Noise Limitations for Aircraft Operations in the Vicinity of Grand Canyon National Park

SUMMARY: This notice of proposed rulemaking proposes to establish noise

limitations for certain aircraft operated in the vicinity of Grand

Canyon National Park. This notice is one part of an overall strategy to

reduce further the impact of aircraft noise on the park environment and

to assist the National Park Service in achieving its statutory mandate

imposed by Public Law 100-91 to provide for the substantial restoration

of natural quiet and experience in Grand Canyon National Park. To this

end, this proposed rule is issued concurrently with a final rule

affecting the Special Flight Rules in the Vicinity of Grand Canyon

National Park, a Notice of Availability of Proposed Commercial Air Tour

Routes for the Grand Canyon National Park and Request for Comments, and

the Draft Environmental Assessment for this Notice. As mentioned above,

this NPRM is issued concurrently with a final rule published elsewhere

in this part of this issue of the Federal Register. Based on Notice No.

96-11, the final rule adds a new subpart to part 93 to codify and

revise the provisions of Special Federal Aviation Regulation (SFAR) No.

50-2, Special Flight Rules in the Vicinity of Grand Canyon National

Park.

DATES: Comments must be received on or before March 31, 1997.

ADDRESSES: Comments on this NPRM should be mailed, in triplicate to:

Federal Aviation Administration, Office of the Chief Counsel,

Attention: Rules Docket (AGC-200), Docket No. 28770, 800 Independence

Avenue, SW., Washington, DC 20591. Comments may also be sent

electronically to the Rules Docket by using the following Internet

address: [email protected]. Comments must be marked Docket No.

28770. Comments may be examined in the Rules Docket in Room 915G on

weekdays between 8:30 a.m. and 5:00 p.m., except on Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Mr. Thomas L. Connor, Mgr, Technology Division, AEE-100, Office of

Environment and Energy, Federal Aviation Administration, 800

Independence Avenue, SW., Washington, DC 20591; Telephone: (202) 267-

8933. For the draft Environmental Assessment contact Mr. William J.

Marx, Division Manager, ATA-300, Federal Aviation Administration, 800

Independence Avenue, SW., Washington, DC, 20591; Telephone: 202-267-

3075.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in this proposed

rulemaking by submitting such written data, views, or arguments as they

may desire. Comments relating to the environmental, energy, federalism,

or economic impact that may result from adopting the proposals in this

notice are also invited. Comments that provide the factual basis

supporting the views and suggestions presented are particularly helpful

in developing reasoned regulatory decisions. Communications should

identify the regulatory docket number and be submitted in triplicate to

the above specified address. All communications and a report

summarizing any substantive public contact with FAA personnel on this

rulemaking will be filed in the docket. The docket is available for

public inspection both before and after the closing date for receiving

comments.

Before taking any final action on this proposal, the Administrator

will consider all comments made on or before the closing date for

comments, and the proposal may be changed in light of the comments

received.

The FAA will acknowledge receipt of a comment if the commenter

includes a self-addressed, stamped postcard with the comment. The

postcard should be marked ``Comments to No. 28770.'' When the comment

is received by the FAA, the postcard will be dated, time stamped, and

returned to the commenter.

Availability of the NPRM

Any person may obtain a copy of this NPRM by submitting a request

to the Federal Aviation Administration, Office of Rulemaking, 800

Independence Avenue SW., Washington, DC 20591, or by calling (202) 267-

9677. Communications must identify the notice number of this NPRM.

Persons interested in being placed on a mailing list for future FAA

NPRM's should request a copy of Advisory Circular No. 11-2A, Notice of

Proposed Rulemaking Distribution System, which describes application

procedures.

An electronic copy of this document may be downloaded using a modem

and suitable communications software from the FAA regulations section

of the Fedworld electronic bulletin board service (telephone: 703-321-

3339) or the Federal Register's electronic bulletin board service

(telephone: 202-512-1661). Internet users may reach the FAA's webpage

at http://www.faa.gov or the Federal Register's webpage at http://

www.access.gpo.gov/su__docs for access to recently published rulemaking

documents.

History

Beginning in the summer of 1986, the FAA initiated regulatory

action to address increasing air traffic over Grand Canyon National

Park (GCNP). On March 26, 1987, the FAA issued Special Federal Aviation

Regulation (SFAR) No. 50 (subsequently amended on June 15, 1987; 52 FR

22734) establishing flight regulations in the vicinity of the Grand

Canyon. The purpose of the SFAR was to reduce the risk of midair

collision, reduce the risk of terrain contact accidents below the rim

level, and reduce the impact of aircraft noise on the park environment.

In 1987, Congress enacted Public Law 100-91, commonly known as the

National Parks Overflights Act. The Act stated, in part, that noise

associated with aircraft overflights at GCNP was causing ``a

significant adverse effect on the natural quiet and experience of the

park and current aircraft operations at the Grand Canyon National Park

have raised serious concerns regarding public safety, including

concerns regarding the safety of park users.''

Section 3 of Public Law 100-91 required the Department of the

Interior (DOI) to submit to the FAA recommendations to protect

resources in the Grand Canyon from adverse impacts associated with

aircraft overflights. The law mandated that the recommendations: (1)

Provide for substantial restoration of the natural quiet and experience

of the park and protection of public health and safety from adverse

effects associated with aircraft overflight; (2) with limited

exceptions, prohibit the flight of aircraft below the rim of the

canyon; and (3) designate flight-free zones except for purposes of

administration and emergency operations.

In December 1987, the DOI transmitted its ``Grand Canyon Aircraft

Management Recommendation'' to the FAA, which included both rulemaking

and nonrulemaking actions. Public Law 100-91 required the FAA to

prepare and

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issue a final plan for the management of air traffic above the Grand

Canyon, implementing the recommendations of the DOI without change

unless the FAA determined that executing the recommendations would

adversely affect aviation safety. After the FAA determined that some of

the DOI recommendations would adversely affect aviation safety, the

recommendations were modified to resolve those concerns.

On May 27, 1988, the FAA issued SFAR No. 50-2 revising the

procedures for operation of aircraft in the airspace above the Grand

Canyon (53 FR 20264, June 2, 1988) SFAR No. 50-2 established a Special

Flight Rules Area (SFRA) from the surface to 14,499 feet above mean sea

level (MSL) in the area of the Grand Canyon. The SFAR prohibited flight

below a certain altitude in each of five sectors of this area, with

certain exceptions. The SFAR established four flight-free zones from

the surface to 14,499 feet MSL above large areas of the park. The SFAR

provided for special routes for commercial sightseeing operators, which

are required to conduct operations under part 135, as authorized by

special operations specifications. Finally, the SFAR contained certain

terrain avoidance and communications requirements for flights in the

area.

A second major provision of section 3 of Public Law 100-91 required

the DOI to submit a report to Congress ``* * * discussing * * * whether

[SFAR No. 50-2] has succeeded in substantially restoring the natural

quiet in the park; and * * * such other matters, including possible

revisions in the plan, as may be of interest.'' The report was to

include comments by the FAA ``regarding the effect of the plan's

implementation on aircraft safety.'' The Act mandated a number of

studies related to the effect of overflights on parks. The National

Park Service (NPS) took longer than originally anticipated to complete

the studies because many of the issues involved are on the cutting edge

of technical and scientific capability. According to the NPS, measuring

natural quiet is different from measuring levels of aircraft noise. On

June 15, 1992, the FAA promulgated a final rule to extend the

expiration date of SFAR No. 50-2 to June 15, 1995, while the NPS

studies and analyses were being conducted (57 FR 26764).

On September 12, 1994, the DOI submitted its final report and

recommendations to Congress. This report, entitled, ``Report on Effects

of Aircraft Overflights on the National Park System,'' was published in

July 1995. The Report recommended numerous revisions to SFAR No. 50-2

that are described below. The NPS Report was based on more than 20

separate studies. These studies included acoustical measurements from

GCNP sites, GCNP visitor surveys, noise dose-visitor response analyses,

and noise modeling of commercial sightseeing aircraft overflying GCNP

using FAA survey data.

The Report concluded that the SFAR had not fully resulted in the

substantial restoration of natural quiet in the Grand Canyon, despite

the improvements it brought. Further, as of 1994, only about 34 percent

of the park could be said to experience a substantial restoration of

natural quiet, and that this would drop to little more than 10 percent

by the year 2000 if growth continued at the same level as predicted.

Only when the NPS made larger flight-free zones and, more importantly,

substituted quieter aircraft into the scenario modeled for 2010, was

achievement of a substantial restoration possible. The NPS Report to

Congress clearly states that reducing noise at the source, as in the

use of quieter aircraft, is the most important ingredient in achieving

the substantial restoration of natural quiet in the Grand Canyon.

On June 15, 1995, the FAA published a final rule that extended the

provisions of SFAR No. 50-2 to June 15, 1997 (60 FR 31608). This action

allowed the FAA sufficient time to review the NPS recommendations and

to initiate and complete any appropriate rulemaking action.

President Clinton, on April 22, 1996, issued a Memorandum for the

Heads of Executive Departments and Agencies to address the significant

impacts on visitor experience in national parks. Specifically, the

President directed the Secretary of Transportation to issue proposed

regulations for the Grand Canyon National Park placing appropriate

limits on sightseeing aircraft to reduce the noise immediately and make

further substantial progress toward restoration of natural quiet, as

defined by the Secretary of the Interior, while maintaining aviation

safety in accordance with Public Law 100-91.

In response to the President's directive, on July 31, 1996 (61 FR

40120; Notice No. 96-11), the FAA published an NPRM to reduce the

impact of aircraft noise on Grand Canyon National Park (GCNP) and to

assist the NPS in achieving its statutory mandate imposed by Public Law

100-91 to provide for the substantial restoration of natural quiet and

experience in GCNP. The NPRM proposed and requested comments on the

following: (1) Modification of the dimensions of the GCNP SFRA; (2)

Establishment of new flight-free zones and flight corridors, as well as

modification of existing flight-free zones and flight corridors; (3)

Proposed flight-free periods and/or an interim moratorium on additional

commercial sightseeing air tours and tour operators; and (4)

Establishment of reporting requirements for commercial sightseeing

companies operating in the SFRA. In addition to these areas, the FAA

sought comment on a number of questions and alternatives regarding

curfews and caps on the number of aircraft and operations, as well as

on the issue of quiet aircraft technology. The comment period for the

proposed rule, originally set for 60 days, was subsequently extended

for another 45 days as directed by the Congress in the Federal Aviation

Authorization Act of 1996 (61 FR 54716; October 21, 1996). In addition

several commenters requested additional time to analyze the complex

components of the proposed rule.

On September 16-20, 1996, in Scottsdale, AZ, and Law Vegas, NV, the

FAA held public meetings to obtain additional comment on the NPRM and

on the draft environmental assessment. Comments and the transcripts of

these meetings have been placed in the rulemaking docket for Notice No.

96-11.

The FAA received approximately 14,000 comments in response to the

NPRM and the public meetings. The FAA has developed a final rule, based

on Notice No. 96-11 and on the public comments to the notice, that is

being issued concurrently with this NPRM published elsewhere in this

part of this issue of the Federal Register.

Interagency Working Group

On December 22, 1993, Secretary of Transportation Federico Pena and

Secretary of the Interior Bruce Babbitt formed an interagency working

group (IWG) to explore ways to limit or reduce the impacts from

overflights on national parks, including GCNP. Secretary Babbitt and

Secretary Pena concur that increased flight operations at GCNP and

other national parks have significantly diminished the national park

experience for some park visitors, and that measures can and should be

taken to preserve a quality park experience for visitors, while

providing access to the airspace over national parks. The Secretaries

see the formation of the working group and the mutual commitment to

addressing the impacts of park overflights as the initial steps in a

new spirit of cooperation between the two departments to promote an

effective balance of missions. The FAA has been working closely with

the NPS to identify and deal with the impacts of

[[Page 69336]]

aviation on parks, and the two agencies will continue to identify and

pursue the most effective solutions. This close cooperation is

necessary because the FAA has sole authority for control of the

nation's airspace to ensure aviation safety and efficiency, while the

NPS is charged with managing the natural and cultural resources in the

national park system and providing for public enjoyment of those

resources in such a manner that they are unimpaired for the enjoyment

of future generations.

The FAA's role in the IWG has been to promote, develop, and foster

aviation safety, and to provide for the safe and efficient use of

airspace, while recognizing the need to preserve, protect, and enhance

the environment by minimizing the adverse effects of aviation on the

environment. The NPS' role in the IWG has been to protect public land

resources in national parks, preserve environmental values of those

areas, and provide for public enjoyment of those areas.

In March 1994, the two agencies jointly issued an advance notice of

proposed rulemaking (ANPRM) seeking public comment on policy

recommendations addressing the effects of aircraft overflights on

national parks, including GCNP (59 FR 12740; March 17, 1994). The

recommendations presented for comment included voluntary measures,

altitude restrictions, flight-free periods, flight-free zones,

allocation of noise equivalencies, and incentives to encourage use of

quiet aircraft technology. On the issue of possible incentives for

quiet aircraft technology, the ANPRM stated:

Air tour operators could be encouraged to use relatively quiet

aircraft on park overflights. For example, a flight corridor with a

good scenic view of the canyon could be limited to aircraft meeting

certain noise emission standards. An air tour operator could find it

advantageous to convert its entire fleet to such quiet aircraft to

incorporate that corridor in its tours. While there is no Federal

requirement for aircraft to be manufactured to produce less noise

than Stage 3 standards, some aircraft appropriate for air tour

operations are quieter than Stage 3. Increased use of such aircraft

in air tours would achieve noise mitigation through reducing noise

levels on the surface of the park, although this option does not

address issues other than noise.

In response to the ANPRM, the FAA received 30,726 comments,

including duplicate form letters and several petitions with multiple

signatures; the FAA received 24,510 submissions of one form letter with

comments addressing the GCNP. Of the total number of comments, 1,975

were distinct letters. This NPRM will discuss only those comments that

relate to establishing aircraft noise limitations at GCNP. The

remainder of the comments relating to the above noted recommendations

may be addressed in a later rulemaking.

Of the 644 comments that specifically addressed GCNP, 337

commenters opposed, while 232 commenters supported, further regulation.

Commenters included members of State and local governments;

congresspersons; helicopter operators; Native Americans and other

individuals; and aviation, environmental, and recreational

organizations and associations.

A number of commenters addressed the issue of quiet aircraft

technology. Commenters opposing additional regulation of aircraft noise

levels argued that quieter aircraft are expensive and incentives to

invest in this technology are needed. Alternatively, commenters said

that noise budgets are too complex and will not work. Commenters

supporting additional regulation urged that incentives to minimize

noise per passenger should be established or that an aircraft noise

budget should be created. Specifically, a few commenters supported the

unconditional adoption of quiet aircraft technology. One commenter

suggested dividing aircraft into noise producing classes, with the

higher noise class airplanes facing greater restrictions. Other

commenters suggested requiring mufflers for all aircraft. The majority

of the comments received on this issue, however, raise concerns with

the adoption of noise-reduction technology. Many commenters stated that

the cost of quiet plane technology is prohibitive at this time. Some

commenters suggested adopting noise abatement equipment as it becomes

affordable. Other commenters suggested using financial incentives--such

as tax incentives, fee abatements, loan programs, and increased

allocation on the number of flights allowed--to encourage operators to

use quiet aircraft. One commenter stated that quiet aircraft technology

is not an adequate solution for the overflight problem because such

aircraft retain impacts and risks other than noise. Another commenter

argued that exploring quiet aircraft technology at this time is not a

worthwhile endeavor because technology will not be able to address the

noise problem in the near future. Another commenter stated that, as an

example for commercial operators, those agencies conducting airflights

over Noise Sensitive Areas should be required to integrate quieter

aircraft into their fleets.

Since the issuance of the joint ANPRM and the formation of the IWG,

the FAA and NPS have been working closely to identify and deal with the

impacts of aviation on GCNP, and the two agencies will continue to

identify and pursue effective solutions. In this spirit of cooperation,

the agencies plan to take the following nonregulatory and regulatory

actions to achieve the substantial restoration of natural quiet in

GCNP.

In addition to the rulemakings concerning GCNP, the IWG is working

to develop a nationwide strategy for addressing noise for the national

park system, and the FAA will be issuing a rule for limiting noise at

Rocky Mountain National Park.

Public Meetings

The FAA has held several public meetings in an effort to obtain

public input for the development of additional actions to reduce the

impact of aircraft noise on GCNP and assist the NPS in its efforts to

restore natural quiet and experience in the park.

On June 28, 1995, the FAA and the NPS jointly published a notice

announcing a public meeting to provide the interested parties with an

opportunity to comment on improving SFAR No. 50-2 (60 FR 33452). The

meeting, held on August 30, 1995, in Flagstaff, AZ, yielded 62 speakers

representing air tour operators, environmentalists, government, tourist

boards, corporations, Native American tribes, and other individuals. An

additional 349 public comments were subsequently received during the

comment period that ended on September 8, 1995.

On September 16-20, 1996, in Scottsdale, AZ, and Las Vegas, NV, the

FAA held public meetings to obtain additional comment on the NPRM and

on the Draft Environmental Assessment for the final rule that is

published elsewhere in this issue of the Federal Register. Comments and

the transcripts of these meetings have been placed in the rulemaking

docket for that final rule.

Congressional Hearings

On October 10-11, 1996, Congressional hearings were held by the

Aviation Subcommittee of the Senate Committee on Commerce, Science, and

Transportation at Las Vegas, Nevada, and Tempe, Arizona. The hearings

were held to gather testimony from various entities involved in or

affected by the FAA's proposed special flight rules over the Grand

Canyon (Notice No. 96-11). Senator John McCain of Arizona made opening

statements at both field hearings indicating that they were there

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to examine the impacts of the proposed rules and the Draft

Environmental Assessment. He hoped the FAA would provide appropriate

incentives for quiet air technology in the final rule.

The Nevada Congressional delegation (Senator Bryan and Congressman

Ensign in person, Senator Reid and Congresswoman Vucanovich by proxy)

indicated, at the Las Vegas hearing, their opposition to Notice No. 96-

11 as written, noting safety concerns as well as ones related to

economics, NEPA compliance, and the lack of quite air technology

incentives.

The issues raised by Senator McCain and other members of the

Arizona delegation were also addressed by others testifying at the

field hearings. There were points (and often counterpoints) raised as

to the effectiveness of SFAR 50-2 in substantially restoring natural

quiet in the Grand Canyon, as mandated by Public Law 100-91; the NPS's

definition of substantial restoration of (50 percent or more of the

park quiet at least 75 percent of the time); methodology involved in

measuring and modeling noise impacts; potential impacts of the new rule

on safety in the SFRA; effects of the new rule on general aviation;

potential adverse impacts of the rule on the economy of Las Vegas and

Nevada; the adequacy of the consultation process with Native American

tribes; and controls on other uses of the park vis-a-vis air tour

overflights.

Many of the air tour operators, some of whom had also voiced

concerns about the safety implications of Notice No. 96-11, predicted

dire economic consequences for the industry if the NPRM, which included

possible caps on operations, curfews, and two additional flight-free

zones, went into effect. In response to the operators' economic

worries, Senator McCain reminded them that they had unanimously opposed

his bill, which became Public Law 100-91, in 1987, claiming that it

would put the entire industry out of business. Instead, he noted, the

number of air tour overflights of Grand Canyon had increased from

approximately 40,000 per annum in 1987 to the 95,000 reported by the

Arizona Republic newspaper for the 12-month period which ended

September 30, 1996.

Aside from a commitment to air safety, perhaps the only issue on

which all of the interests represented at the field hearings appeared

to agree was the need for quiet air technology incentives for both

manufacturers and air tour operators. From Senator McCain and members

of the Nevada Congressional delegation to the Native American tribal

leaders and from environmental groups to air tour operators and

aircraft manufacturers, as well as aviation and tourism industry

representatives, quieter air technology incentives were viewed as

integral to efforts to substantially restore natural quiet to the Grand

Canyon while maintaining a viable air tour industry. Among specific

suggestions made were providing more attractive routes to quieter

aircraft, setting aside a portion of air tour overflight fees to

provide loans to air tour operators to invest in further quiet air

technology, and lowering fees for those operators using quieter

aircraft.

The FAA has considered the statements made at the hearings in

developing this proposed rule.

Consultation With Affected Native American Tribes

Three Native American reservations border GCNP, and several

additional tribes have cultural ties to the Grand Canyon. The DOT and

DOI recognize that before taking any action, they have an obligation to

consult with these tribes on a government-to-government basis. The

consultation process, begun with the development of the proposed and

final rule for the reduction of aircraft noise on GCNP, will continue

with this process.This will include a continuing dialogue with tribes

potentially affected by this proposal and will include direct meetings

as well as written consultation. Initial steps have been taken to

contact potentially affected tribes of this proposal based on the

government-to-government relationships.

Relationship to Final Rule Published Concurrently

As mentioned above, the FAA has developed a final rule, based on

Notice No. 96-11 and on the public comments to the notice, that is

being issued concurrently with this NPRM as published elsewhere in this

part of this issue of the Federal Register.

Notice No. 96-11 proposed and requested comments on the following:

(1) Modification of the dimensions of the GCNP Special Flight Rules

Area (SFRA); (2) Establishment of new flight-free zones and flight

corridors, as well as modification of existing flight-free zones and

flight corridors; (3) Proposed flight-free periods and/or an interim

moratorium on additional commercial sightseeing air tours and tour

operators; and (4) Establishment of reporting requirements for

commercial sightseeing companies operating in the SFRA. In addition to

these areas, the FAA sought comment on a number of questions and

alternatives regarding curfews and caps, as well as on the issue of

quiet aircraft technology. The final rule for Notice No. 96-11

addresses all of these areas except for the issue of quiet aircraft

technology. The FAA did not include requirements on quiet aircraft

technology in the final rule, because Notice 96-11 did not propose

specific measures on that subject; instead the FAA requested comments

and information that would allow the FAA to develop a specific

proposal. Based on a review of the comments on quiet technology

received on Notice No. 96-11, summarized below, the comments received

at the FAA and Congressional public meetings, the comments received on

the ANPRM published in 1994, and the NPS Report to Congress, the FAA is

issuing this NPRM. Comments received to date on quiet technology will

be considered in conjunction with comments submitted in response to

this proposed rule.

Comments Concerning Quiet Technology

One commenter states that the largest operators at the Grand Canyon

have either converted to quiet technology or are in the process of

converting.

Papillon says that quieter aircraft is the solution to the problems

raised in the NPRM and, in addition to describing the current

technology available, recommends establishing a time frame for

transition to quiet technology; establishing guidelines to qualify

aircraft as quiet; and encouraging and assisting tour operators to

convert their fleets to quiet technology aircraft.

Sierra Club-Grand Canyon Chapter says that the goal should be to

completely phase in quiet technology aircraft over the next 10 to 15

years, with no increase and even a decrease in the number of flights.

This commenter says that new aircraft should not be louder than the

aircraft they replace and that if a noise budget approach is developed,

there should be a reduction factor.

The National Parks and Conservation Association (NPCA) asserts the

necessity of incorporating quiet flight technology into the rule by

noting that sound can travel 13 to 16 miles laterally from aircraft and

penetrate deeply into flight-free areas.

A river tour company notes the use of the Thrush TurboPro for drug

interdiction. This commenter believes that if the demand were created

for ``hush kits'' on smaller aircraft via FAA rulemaking, manufacturers

would develop and produce this type of technology at cheaper prices

than are currently available.

Some commenters submitted technical information about quiet

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aircraft that are currently available or being developed. In addition,

at the Congressional hearing, the National Aeronautics and Space

Administration (NASA) submitted information on research and development

efforts (by NASA and the FAA) on quiet aircraft technology for

propeller-driven airplanes and rotorcraft. The FAA has considered this

information in developing this proposed rule.

Some commenters, such as the Grand Canyon Air Tour Association

(GCATA), Twin Otter, and Grand Canyon Airlines say that the proposed

rules in Notice No. 96-11 will make it difficult for small operators to

generate the revenue to invest in quieter aircraft. These commenters

(some of whom have already employed quieter, more expensive aircraft)

recommend that incentives such as tax credits, preferred routes and

altitudes, elimination of overflight fees, and no curfews or caps, be

made available to tour operators who wish to invest in quieter

aircraft. Twin Otter and Grand Canyon Airlines add that the use of

quieter and larger aircraft would be beneficial by reducing the number

of air tour operations required to carry the same number of passengers,

which would further reduce noise levels.

Twin Otter and Grand Canyon Airlines recommend withdrawing the NPRM

and replacing it with incentives for quiet aircraft technology. Another

commenter says that the FAA should not take a regulatory approach;

rather, government should work with private enterprise to develop

quieter aircraft.

Some commenters (e.g., Grand Canyon Trust, Wilderness Watch,

Wilderness Society, Grand Canyon River Guides) state that a stronger

rule is needed that would provide incentives for conversion of the

existing tour fleet to the quietest aircraft available. Grand Canyon

Airlines recommends that interim milestones be set by which existing

conventional air tour aircraft fleets are converted to quiet aircraft;

these milestones could be similar in concept to those established in 14

CFR part 91 for air carrier compliance with 14 CFR part 36 for Stage 3

certification standards.

McDonnell Douglas Helicopter Systems (MDHS) supports offering

economic incentives to encourage air tour operators to operate

helicopters equipped with quiet technology. Since 1991, MDHS has

provided many quiet technology ``No Tail Rotor'' (NOTAR) helicopters

which are operating effectively in noise-sensitive environments. In

addition to the types of incentives mentioned by other commenters (see

above), MDHS recommends the use of airspace entry locations based on

FAA noise certification data for each type of helicopter. MDHS also

recommends that Federal government agencies operating within the

national parks should set an example by acquiring and using quiet

technology aircraft.

Another commenter suggests allowing those operators who own

measurably quieter machinery a 5 percent credit on their allotted

number of flight permits. According to the commenter, operators who

persist in running noisy aircraft should be subject to penalties

restricting their permits.

Another commenter suggests a fee per flight that would encourage

the use of larger, quieter aircraft by multiplying that fee by the

sound level. This commenter believes that if this is used in

conjunction with a limitation on the number of total tour flights

permitted, operators would be encouraged to use quieter aircraft.

A BIA representative says that requirements for high-technology

quiet aircraft should provide a specific exemption to Native American

tribes for any flights sanctioned by such Native American tribes over

their own lands.

The FAA agrees that the use of quieter aircraft will, in the long

run, provide the most benefit toward restoring natural quiet. As

discussed later in this preamble, this proposal contains a phase out

schedule for noisier aircraft, a requirement that newly acquired

aircraft meet certain acoustic criteria, and an incentive for using

quieter aircraft by allowing flights though the proposed National

Canyon route to be conducted with only the aircraft that meet this

acoustic criteria. The FAA has considered the comments received on

Notice No. 96-11 in developing the specific proposals described below.

The FAA and NPS are working together to develop a long-term

Comprehensive Noise Management Plan that will address the best

available technology, provision of appropriate incentives for investing

in quieter aircraft, and appropriate treatment for operators that have

already made such investments. As discussed below under ``Potential

Further Action,'' the FAA and NPS solicit comments on the types of

considerations that should be included in this plan. Both FAA and NPS

are committed to the development of a noise management plan over the

next 5 years.

The Proposal

This proposed rule has several purposes. The first would be to

provide an incentive for the use of quieter aircraft within GCNP. The

second would be to establish additional noise limitations to reduce

further the impact of aircraft noise on the park environment in the

GCNP. The third would lift for the quietest aircraft the immediate

temporary cap placed on the number of aircraft permitted to be used for

commercial sightseeing operations in GCNP.

National Canyon Corridor

The companion final rule published elsewhere in this part in this

issue of the Federal Register expands the Toroweap/Shinumo Flight-free

Zone to prohibit operations in the airspace area that is now used by

operators for commercial sightseeing operations while flying from Las

Vegas to Tusayan. This proposal would establish a corridor, referred to

as the National Canyon Corridor, within the newly expanded Toroweap/

Shinumo Flight-free Zone that would enable operators using GCNP

Category C aircraft (the quietest category of aircraft, as discussed

below) to reinitiate commercial sightseeing operations along this route

from Las Vegas to Tusayan without having to circumnavigate the

Toroweap/Shinumo Flight-free Zone.

Phase-Out of Noisier Aircraft

In addition, the purpose of this proposal is to establish

additional noise limitations to reduce further the impact of aircraft

noise on the park environment in the Grand Canyon National Park. This

proposal would accomplish this goal by a combination of requirements

that would limit future use of noisier aircraft and that would provide

incentives for the use of quieter aircraft. As discussed below, the

proposed phase out of the GCNP Category A aircraft would provide a

major reduction in noise by the end of the year 2000 and make a major

contribution toward achieving the Congressional mandate of substantial

restoration of natural quiet. Modeling shows that, if the phase out is

adopted as proposed, the substantial restoration objective would be

exceeded by 2008. The subsequent phase out of GCNP Category B aircraft

would ensure continued restoration of natural quiet, as required by the

NPS, even when projected numbers of additional GCNP Category C aircraft

are added to the commercial sightseeing fleet.

The FAA has evaluated the noise exposure of existing aircraft used

in the GCNP and has divided those aircraft into three categories based

on noise per passenger or ``noise efficiency'': GCNP Category A

aircraft includes the least noise efficient aircraft currently in use

for sightseeing operations in the vicinity

[[Page 69339]]

of the Grand Canyon National Park; GCNP Category B aircraft includes

aircraft more noise efficient than Category A aircraft but less noise

efficient than the quietest aircraft now available; and GCNP Category C

aircraft includes affected aircraft which are the quietest currently

available. A detailed discussion of the technological basis for these

categorizations is in the following section of this preamble, entitled

``Quiet Technology for GCNP.''

This proposal would in effect prohibit any further acquisition of

GCNP Category A aircraft for use in the SFRA by persons conducting

sightseeing operations. Current operators with Category A aircraft

could continue to use that number of GCNP Category A aircraft listed on

the operator's operations specifications on December 31, 1996, but that

use of GCNP Category A aircraft would have to end on or before December

31, 2000.

Current operators of GCNP Category B aircraft would be allowed to

continue to use that number of aircraft listed on the operating

specifications as of December 31, 1996, and on or before December 31,

2000, as a replacement for GCNP Category A aircraft, but would be

required to phase out all of those aircraft on or before December 31,

2008. The proposed phase out schedule would require that on or before

December 31, 2002, at least one-quarter of the number of Category B

aircraft listed on the operator's operations specifications on December

31, 2000, (the base level) would have to be phased out. The remaining

Category B aircraft would have to be phased out in 25 percent

increments so that no more than 50 percent of the base level aircraft

would be in use after December 31, 2004, 25 percent after December 31,

2006, and all Category B aircraft would have to be phased out on or

before December 31, 2008. During the period of time after the effective

date of a final rule and on or before December 31, 2000, an operator

could replace Category A aircraft with Category B or C aircraft but

only on a one-for-one basis.

While the proposed rule would allow the continued use of Categories

A and B aircraft by current certificate holders as described above, all

aircraft used by new entrants to the affected sightseeing area would

have to meet Category C requirements. This means that any person who

wants to establish an aircraft sightseeing operation in the affected

area after the effective date of a final rule would have to use only

Category C aircraft. Also, all new aircraft acquired by present

operators above the total number of Category A and B aircraft listed on

the operations specifications of each operator on December 31, 1996,

would have to be Category C aircraft.

The FAA is soliciting comments on all aspects of the proposed

phase-out plan, including the affected aircraft, the schedule and

percentage of aircraft that would be affected by any such plan.

Comments focusing on the economic and environmental impact of the

proposed phase-out would be beneficial.

Comments on Alternative Proposal

Comments are particularly requested on a potential alternative to

the proposal to allow an operator to replace Category A aircraft with

either Category B or Category C aircraft. Under the alternative,

Category A aircraft could only be replaced by Category C aircraft. No

interim replacement by Category B would be permitted. Because this

would hasten the elimination from the GCNP of all aircraft other than

Category C, it is likely to achieve the goal of attaining natural quiet

more rapidly than the primary proposal set forth in this notice. This

alternative was not incorporated into the current proposal, however,

because the FAA's preliminary analysis suggests that it could be

significantly more costly to operators. (See the Appendix to the

Regulatory Evaluation contained in the docket.) These costs could be

particularly burdensome to small entities.

However, if the additional costs of a direct transition from

Category A to Category C are lower than they currently appear, and

substantial additional environmental benefits may be obtained at

reasonable cost, the final rule adopted in this proceeding could

incorporate the alternative approach. Before taking final action,

therefore, the FAA intends to further refine its cost estimates and the

likely burden on small operators. Toward that end, it would be

especially helpful if commenters provide specific cost and

environmental projections that compare the impact of the primary

proposal with the alternative. The FAA requests answers to the

following questions, along with any other relevant information

commenters wish to provide. Please note that comments accompanied by

specific data about costs and/or environmental effects will be more

useful than arguments of a general nature.

From a business economic standpoint, would allowing the

interim conversion of Category A aircraft to Category B be less

burdensome than direct conversion to Category C?

Does the cost of Category C aircraft exceed the cost of

Category B aircraft? If so, by how much? What options other than direct

purchase of Category C aircraft would be available that may have an

effect on the economics of conversion?

What is the availability of used Category C aircraft, and

how could the acquisition of used aircraft mitigate the cost of the

alternative?

Are there business reasons that would cause operators to

choose to replace Category A aircraft with Category C, even if Category

C aircraft are more expensive than Category B aircraft? For example,

would the subsequent need to phase out Category B make the option of an

interim step undesirable in any event? Similarly, do Category C

aircraft offer advantages in operating efficiency, marketability of air

tours, repair costs, or other factors that would reduce the overall

cost differences between acquiring Category B and Category C aircraft?

Would other methods of analysis that include such factors

as the cost of capital, long-term tax consequences, and other factors

be more useful in determining the economic impacts of the conversion?

If so, how should those factors be taken into account?

What would be the noise-reduction consequences of

requiring a direct transition from Category A to Category C? The

replacement of Category A aircraft (by either Category B or Category C)

is likely to make the greatest contribution toward the restoration of

natural quiet. Insofar as quantification is possible, it would be

useful to understand how much additional benefit could be obtained by

going directly to Category C.

Removal of Temporary Cap

Under the companion final rule published today, an immediate

temporary cap is placed on the number of aircraft permitted to be used

by each operator for commercial sightseeing operations in the Grand

Canyon SFRA. If this notice is adopted as proposed, a cap on the total

number of Category A and Category B aircraft permitted to operate in

GCNP would remain in effect. However, the cap on Category C aircraft

would be lifted. As a result, the fleet size of Category C aircraft

could grow, subject to safety considerations, market-based

considerations, or recommendations from the Comprehensive Noise

Management Plan. For a more detailed discussion of this issue, see

``Potential Further Action'' below.

Quiet Technology for GCNP

This section of the preamble is a summary of a technical paper

describing the methodology for classifying noise characteristics for

aircraft operating in

[[Page 69340]]

GCNP. The full document has been placed in the docket for this

rulemaking and is available for viewing and comment as described above

under ADDRESSES. To obtain a copy of this document, contact the person

listed under FOR FURTHER INFORMATION CONTACT.

Introduction

In response to comments in the docket for Notice No. 96-11 and

those made at public hearings, FAA redoubled its efforts to develop

concepts which would provide incentives for tour operators to invest in

the best available noise abatement technology. Traditionally, the FAA

uses its regulatory authority to impose more stringent national noise

standards when it has been determined to be appropriate. By law when

deciding on further noise stringency, FAA must ascertain whether the

proposal is technologically feasible, economically reasonable, and

appropriate to aircraft type. Based upon a joint FAA/NASA research

report to Congress on quiet technology \1\ and earlier work prepared

for the third meeting of the Committee on Aviation Environmental

Protection (CAEP) under the International Civil Aviation Organization

(ICAO), the FAA determined that the imposition of new national and

international noise standards for propeller-driven small airplanes and

helicopters is not appropriate at this time. While there is ongoing

research by the Federal government to identify future noise abatement

technology, current aircraft designs already incorporate most of the

available technology within economic reasonableness. At GCNP, there are

substantive differences in the noise characteristics of the air tour

aircraft in use. Therefore, FAA looked to non-traditional concepts

which could offer some incentive for tour operators to improve the GCNP

situation.

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\1\ Report of the FAA and NASA to the U.S. Congress Pursuant to

Section 308 of the FAA Authorization Act of 1994, ``Quiet Aircraft

Technology for Propeller-driven Airplanes and Rotorcraft,'' June

1996.

---------------------------------------------------------------------------

Noise Efficiency Concept

One theme expressed by some commenters was that the use of quieter,

larger aircraft would provide two-fold benefits in reducing noise of

each operation and reducing the number of operations to carry the same

number of passengers. This theme fits in nicely with the FAA's general

policy of using cumulative aircraft noise as an appropriate measure of

the potential impact as it accounts for both the number of flights and

intensity of their noise. The FAA began to explore noise efficiency

concepts as an incentive for operators to utilize aircraft equipped

with the best available noise abatement technology in the park. The

following attributes were used in judging potential concepts:

Is based on aircraft noise certification (14 CFR part 36).

Judges fixed- and rotary-wing aircraft on a common basis.

Correlates with aircraft performance and operation at

GCNP.

Offers basis for incentives.

Is manageable.

In addition to these attributes, the concept must be shown to be

economically reasonable.

Links to Aircraft Noise Certification

Levels obtained from aircraft noise certification represent the

highest quality of data available. The flight tests are conducted under

controlled conditions with an FAA representative or designee in

attendance to witness the test setup and test activities. Data obtained

during these tests are corrected to standard reference conditions as

prescribed in 14 CFR part 36. FAA publishes these levels in Advisory

Circular 36-1, ``Noise Levels for U.S. Certificated and Foreign

Aircraft.'' The current version of this AC is 36-1F dated 6/5/92.

Unfortunately there is no single method applicable to all aircraft for

determining the certificated noise level. Depending on date of

application for type certificate and whether the aircraft is a

helicopter or airplane, the noise level could have been obtained from

one of 4 different tests, Appendices F, G, H, and J of 14 CFR part 36.

Because these noise certification procedures contain differences in

aircraft operation, measurement altitudes, and units of noise, it is

not possible to directly compare Appendix F, G, H, and J noise levels.

However, FAA has developed a procedure for: (1) Extrapolating from the

controlled conditions of a certification test to the operating

conditions at GCNP and (2) converting levels to a common noise unit,

thus making it possible to judge fixed- and rotary-wing aircraft on a

common basis under conditions that pertain to air tour operations over

GCNP. Sound Exposure Level (SEL) was selected as the common noise unit.

SEL is a basic building block in calculating Equivalent Sound Level

(Leq) which is the measure of cumulative noise exposure that FAA

is using to assess noise impacts in GCNP. (Leq) is the most common

method used to quantify time-varying noises. The Federal government

uses a form of equivalent sound level, Day Night Sound Level (DNL), to

quantify aircraft noise exposure in the vicinity of airports.

Noise Efficiency Measure

These extrapolation procedures for predicting noise levels

applicable to Appendices F, H, and J of 14 CFR part 36 enable one to

directly compare propeller-driven small airplanes and helicopters.

There is no extrapolation procedure for Appendix G. The noise

efficiency criterion for Appendix G noise levels was derived by a

method that is explained later. In keeping with the theme of developing

a noise efficiency concept, the extrapolated noise levels were examined

as a function of the number of seats of the aircraft in the fleet of

air tour aircraft operating at GCNP. Since the principal business of

these aircraft is to carry sightseers over the park, the number of

passenger seats is a logical production (or efficiency) factor.

When the aircraft noise levels are plotted against the number of

passengers, there appears to be a break or gap between groups of

aircraft that support some NPS findings on ``quiet aircraft.'' The NPS

report to Congress identifies the DHC-6-300 Twin Otter (``Vistaliner''

version), the Cessna Caravan I, and the McDonnell Douglas ``No Tail

Rotor'' (NOTAR) helicopters as the quietest aircraft currently

operating at GCNP. The report further states that NPS expects that

these aircraft would qualify under a ``quiet aircraft'' category.

A line of a demarcation can be drawn between the quietest aircraft

and the rest of the air tour fleet. The two components of the line are:

(1) Horizontal until greater than 2 passenger seats, and (2) increasing

slope at 3 dB per doubling of number of seats. The line is horizontal

until the number of seats is greater than 2 because a review of

aircraft specification data found that two is the least number of

passenger seats found on an aircraft that had been operated as an air

tour aircraft in GCNP. Specifying a limit that increases with the

number of seats is consistent with FAA's philosophy of rewarding

efficiency by allowing aircraft which carry more passengers to emit

more noise, thus creating less noise per passenger. For example, the

slope of Appendix H noise limit increases at the rate of 3 decibels per

doubling of weight. For aircraft in these weight ranges, 3 dB per

doubling of number of seats is a comparable growth rate to 3 dB per

doubling of weight. Figure 1 shows noise levels of many of the air tour

aircraft against the number of passenger seats in the aircraft.

[[Page 69341]]

The area below the solid line in Figure 1 is proposed as the

potential objective in the encouragement of compatible noise abatement

technology for air tour operations in GCNP. This area is labeled ``C''

and the aircraft whose SELs fall within this region are ``GCNP Category

C aircraft.'' Another dotted line is plotted at 4 decibels above the

solid line in Figure 1 which creates two new areas each covering 4

decibels and evenly splits the number of air tour aircraft into these

two zones. The two new areas are labeled ``A'' and ``B.'' Aircraft

whose noise levels fall within these new zones are identified as GCNP

Category A and GCNP Category B aircraft, respectively. An examination

of a recent count of air tour aircraft finds that there are 57 GCNP

Category A aircraft, 56 GCNP Category B, and 23 GCNP Category C

aircraft operating at GCNP.

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Noise Efficiency Criteria

The curves in Figure 1 demonstrate the general concept and are the

bases for the noise efficiency criteria. A workable criterion should be

easy to apply and manage in the field and should be understandable to

the operators and general public. The airport community has many years

of experience using the certificated noise levels published in FAA's AC

36-1F. These data have been used to establish use restrictions,

curfews, and noise budgets at some airports in the country. The

certificated noise levels are not only available in advisory circulars

which are updated and published periodically but the levels are readily

available to the aircraft owners from the aircraft flight manuals

(AFM). Thus the development of noise efficiency criteria based on

certificated noise levels is proposed not only because of the

precedent, but it also eliminates the need for someone in the field to

perform the mathematical extrapolation from certification to GCNP

conditions by the method that was outlined in the section ``Links to

Aircraft Noise Certification.''

By reversing the process that determined the noise levels in Figure

1, the two lines in Figure 1 are translated into three GCNP noise

efficiency criteria for Appendices F, H, and J. These are shown in

Figures 2a, 2b, and 2c, respectively. The figures also contain the

equations for the GCNP Categories B and C noise efficiency criteria or

noise limits. These are the criteria for compliance with the proposed

regulation.

As stated earlier, this study did not discover a method to

successfully extrapolate Appendix G noise levels to GCNP conditions.

When FAA promulgated Appendix G to supersede Appendix F, the change was

to replace the level flyover test with a takeoff test. The Appendix G

noise limit is 5 decibels higher than the Appendix F noise limit to

account for difference in measured noise levels obtained under the

different test conditions. Applying that philosophy to this situation,

a noise efficiency criterion for Appendix G noise levels can be derived

by adding 5 decibels to the criteria for Appendix F. There is no figure

in this paper, similar to Figures 2a-c, showing the Appendix G noise

efficiency criteria because all of the propeller-driven airplanes

currently operating at GCNP predate the promulgation of Appendix G of

14 CFR part 36. The equations of the noise efficiency criteria for

Appendix G are found in Appendix B of the proposed rule.

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[[Page 69343]]

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[[Page 69344]]

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[[Page 69345]]

Implementation

The proposed GCNP aircraft noise incentive concept links to the

aircraft noise certification provisions prescribed in 14 CFR part 36.

The incentive criteria will be based upon the noise levels obtained

under noise certification conditions. The use of noise certification

levels will provide an ability to judge fixed- and rotary-wing aircraft

on a common basis.

New aircraft are subject to the provisions of 14 CFR part 36

including the requirement to conduct a noise certification test under

controlled conditions. This test is conducted in accordance with an FAA

approved test plan and is typically witnessed by FAA personnel unless

delegated to an FAA designee. Some aircraft, depending on the date of

type certification, were not subject to the noise certification

provisions of 14 CFR part 36. Thus noise certification levels are

unknown. In the strict sense certification noise tests should be

required to establish noise levels for comparative purposes against the

GCNP aircraft noise efficiency criteria.

The FAA does not have the authority to mandate that those older

aircraft conduct such tests for compliance with the provisions of 14

CFR part 36. However, in order to fully implement the GCNP aircraft

noise incentive concept, noise certification levels or estimates of

those levels under certification conditions will be required.

Considering the overall cost associated with conducting noise

certification tests and establishing noise certification levels it is

proposed to offer a hierarchy of noise level data source options for

establishing noise levels to fully implement the GCNP aircraft noise

incentive concept. FAA plans to publish an Advisory Circular (AC 36-XX)

that will facilitate the determination of the noise levels for the GCNP

noise efficiency criteria. This AC would list all aircraft operating at

Grand Canyon National Park as determined from operations

specifications. Noise levels would be specified for each aircraft

listed in the AC.

In some cases the noise levels listed in this proposed AC would be

the actual FAA approved noise certification levels documented in the

FAA approved airplane or rotorcraft flight manuals. These level are

typically provided in FAA AC 36-1 and would simply be referenced in the

proposed GCNP AC. In other cases where noise certification under 14 CFR

part 36 was not required, the noise level could be provided to the FAA

by the operator or owner following the hierarchy described below. The

owner or operator would have to substantiate to the FAA that the

estimated noise level is representative for the subject aircraft.

The following hierarchy of noise level data sources would be

documented in the proposed AC and used for all aircraft in determining

the noise level for the GCNP aircraft noise incentive concept:

1. US certifications under 14 CFR part 36 with noise certification

levels obtained from the FAA approved flight manuals or FAA AC 36-1.

(a) For propeller driven small airplanes the applicable hierarchy

of regulations are:

(1) 14 CFR part 36 Appendix F.

(2) 14 CFR part 36 Appendix G.

(b) For helicopters the applicable hierarchy of regulations are:

(1) 14 CFR part 36 Appendix J.

(2) 14 CFR part 36 Appendix H.

2. Foreign certifications under ICAO Annex 16, Volume I with noise

certification levels obtained from the approved flight manuals or data

approved by the foreign civil aviation authorities, or FAA AC 36-1.

(a) For propeller driven small airplanes the applicable hierarchy

of regulations are:

(1) ICAO Annex 16, Volume I Chapter 6.

(2) ICAO Annex 16, Volume I Chapter 10.

(b) For helicopters the applicable hierarchy of regulations are:

(1) ICAO Annex 16, Volume I Chapter 11.

(2) ICAO Annex 16, Volume I Chapter 8.

3. Research or other measurement test data obtained under

controlled conditions, documented and corrected to the certification

conditions of Appendix F for small propeller driven airplanes and

Appendix J for helicopters. Preference would be placed on those data

obtained under certification-like conditions and/or those data

collected under an FAA sponsored noise research test.

4. FAA approved noise estimation methods that can estimate Appendix

F noise levels for small propeller driven airplanes and Appendix J

noise levels for helicopters. Currently the following methods may be

suitable for use pending FAA approval on a case by case basis.

(a) For propeller driven small airplanes: Method in Section 2.2 of

DOT/FAA/AEE-82-1.

(b) For helicopters: SAE/AIR 1989.

As one moves down on the hierarchy the expected level of

substantiation (as the representative noise certification level-

estimated) by the operator or owner would increase, and the level of

FAA scrutiny should be expected to increase.

The resulting noise levels will vary depending upon an operator's

or owner's situation related to the above hierarchy. In the case of

helicopters the noise levels will be the flyover noise certification

level in the noise metric of Effective Perceived Noise Level (EPNL) (14

CFR part 36, Appendix H) or Sound Exposure Level (SEL) (14 CFR part 36,

Appendix J). In the case of small propeller-driven airplanes the noise

levels will be the flyover (14 CFR part 36, Appendix F) or takeoff (14

CFR part 36, Appendix G) noise certification level in the noise metric

of maximum A-weighted sound level. It is estimated that noise levels

for virtually all aircraft currently operating in GCNP could be

achieved without the need for a complete noise certification test.

All estimated noise certification levels provided in the proposed

FAA AC 36-XX would be for the sole and specific purpose of determining

compliance with Grand Canyon noise efficiency criteria.

NPS Air Operations

GCNP has one of the most strictly regulated aviation programs

within the NPS and the DOI. The park limits use of its contracted

aircraft to activities involving life or health-threatening

emergencies, administration and/or protection of resources, and for

individually approved special purpose missions. Each flight request is

reviewed to ensure that it is the most efficient, economical, and

effective method of performing the required task consistent with NPS

and GCNP goals. These goals include the protection of natural quiet and

experience, as reinforced by the park's recently approved General

Management Plan. The NPS is revising its contract requirements so that

it can contract for quieter aircraft that meet mission requirements,

and it is addressing this in budget formulation as a high priority

need. The NPS will, to the maximum extent possible, meet or exceed

phase-out schedules for the air tour industry at large and will to the

maximum extent feasible honor flight-free zones established for the

Park. GCNP seeks to make this conversion in advance of the requirements

of this rule.

Development of a Comprehensive Noise Management Plan

This proposed rule reflects the understanding of the FAA and NPS

that the conversion of the commercial sightseeing aircraft fleet

operating in the SFRA to a more noise efficient fleet is

[[Page 69346]]

the most promising approach to providing for the substantial

restoration of natural quiet mandated by Public Law 100-91 and allowing

for some measure of growth in the commercial sightseeing industry. To

ensure that the proposed rule provides the fairest solution for all

parties involved, the FAA and NPS are committed to the joint

development of a noise management plan no later than 5 years from May

1, 1997. It will provide for a more adaptive management system, full

resolution of all monitoring and modeling issues, improved public

input, and the provision of improved incentives to invest in noise

efficient aircraft. The purpose is to further refine the final rule

published concurrently with this proposed rule, whose intent is to

provide for the substantial restoration of natural quiet mandated by

the Overflights Act. To ensure development of a flexible and adaptive

approach to noise mitigation and management, this plan will, at a

minimum, (1) address development of a reliable aircraft operations and

noise database, (2) validate and document the most effective uses for

FAA and NPS noise models in GCNP, (3) explore how the conversion to a

noise efficient fleet can most effectively contribute to the

substantial restoration of natural quiet while allowing for growth in

the industry, and how, in this context, incentives can best be provided

to promote this conversion. The FAA and the NPS are committed to an

open process that will provide for full public involvement.

In the development of the Comprehensive Noise Management Plan,

consideration will be given to the inclusion of additional reporting

requirements. The final rule published elsewhere in this part of this

issue of the Federal Register does not require that operators report on

their commercial sightseeing operations and aircraft used with the SFRA

beyond the year 2002. Some type of additional information after that

time will be required. The FAA is requesting comments on the type of

information and the method of collecting that information that would be

most consistent with this plan. Comments will be considered during the

development of the Comprehensive Noise Management Plan.

Potential Further Action

As proposed, the FAA would remove the temporary cap placed on

certain aircraft permitted to be used for commercial sightseeing

operations in GCNP. This is in response to the cap established by the

companion final rule published elsewhere in this part in this issue of

the Federal Register.

The proposed rule would permit operators conducting commercial

sightseeing operations within the SFRA to replace GCNP Category A

aircraft with GCNP Category B aircraft until December 31, 2000.

According to the proposed requirements of the phase-out, the GCNP

Category B aircraft could be used until December 31, 2008. Furthermore,

the proposed rule allows the substitution of GCNP Category B aircraft

with other GCNP Category B aircraft until December 31, 2008. In this

context, should operators be restricted to replacing either GCNP

Category A and B aircraft only with GCNP Category C aircraft?

As proposed in this notice, the removal of the cap would enable the

fleet size to grow. Fleet conversion to larger and quieter aircraft

provides for industry growth and noise reduction. But since there is

ultimately some capacity level that is consistent with the substantial

restoration of natural quiet, which the FAA and NPS will address in the

development of a Comprehensive Noise Management Plan, the FAA is

requesting specific comment on how to address this ``capacity'' issue:

--Should an overall cap on the fleet size be maintained until the

Comprehensive Noise Management Plan is completed? Or should the number

of Category C aircraft in the fleet be allowed to grow through random

addition until it reaches the size recommended in the Comprehensive

Noise Management Plan to be in concert with one that will maintain the

substantial restoration of natural quiet in GCNP?

--At what size should the fleet be capped? What is the appropriate

baseline to establish for imposition of a fleet cap? And if imposed,

what would the effect be on transitioning to noise efficient aircraft?

What provisions should be made for changes in technology that result in

increased aircraft efficiency and sound reduction?

--Should incentives be included in a ``flexible'' cap that would permit

increasing numbers of aircraft based on acquisition of leading edge

noise efficient technology by operators? Should growth be tied to an

incentive system for existing operators to convert their fleet to more

noise efficient aircraft? For example, an operator converting two GCNP

Category A aircraft to GCNP Category C aircraft could add an additional

GCNP Category C aircraft, for a total of three GCNP Category C

aircraft. And an operator converting three GCNP Category B aircraft

would be permitted to add one additional GCNP Category C aircraft, for

a total of four GCNP Category C aircraft.

--Should caps be applied more selectively to specific routes or

corridors that are more noise-sensitive, such as the Dragon Corridor?

The FAA is specifically requesting comments on how to better

protect areas adjacent to the Dragon Corridor, identified by the NPS as

among the most noise-sensitive areas in the GCNP. To minimize the

amount of noise from commercial sightseeing aircraft in the Dragon

Corridor, the FAA solicits comments on the following alternatives:

Removing the two-way loop permitted for helicopters in the

Dragon Corridor and reinstating the two-way loop in the Zuni Corridor.

Accelerating the proposed phase-out schedule for aircraft

operating in the Dragon Corridor.

Permitting only GCNP Category C aircraft to operate in two

directions within the Dragon Corridor.

Environmental Review

The FAA has prepared a draft environmental assessment (EA) for this

proposed action to assure conformance with the National Environmental

Policy Act of 1969. A copy of this draft EA will be circulated to

interested parties and placed in the docket, where it will be available

for review. For those unable to view the document in the docket, the

Draft EA can be obtained from the person listed in the FOR FURTHER

INFORMATION CONTACT section listed previously. The comment period on

the Draft EA will remain open for 90 days from the date of the

publication of this Notice. Before the final rule is issued, the FAA

will prepare a Final EA and determine whether a Finding of No

Significant Impact may be issued or an environmental impact statement

is required.

Regulatory Evaluation Summary

Changes to federal regulations must undergo several economic

analyses. First, Executive Order 12866 directs Federal agencies to

promulgate new regulations or modify existing regulations only if the

potential benefits to society justify the costs. Based on the criteria

outlined in E.O. 12866, the Department of Transportation has concluded

that this rulemaking would constitute a ``significant regulatory

action'' and, as such, must include an analysis of alternative actions.

Second, the Regulatory Flexibility Act of 1980 requires agencies to

analyze the

[[Page 69347]]

economic impact of regulatory changes on small entities. Finally, the

Office of Management and Budget directs agencies to assess the effects

of regulatory changes on international trade.

In conducting these assessments, the FAA has determined that the

combined quantifiable and non-quantifiable benefits of the proposed

rule would exceed costs. The FAA has also determined that the rule

would not have any significant impact on international trade. In

addition, the FAA has estimated that the rule would have a significant

economic impact on a substantial number of small air tour operators.

Therefore, a regulatory impact analysis is included as required by law.

These analyses, available in the docket, are summarized below.

Introduction

This regulatory evaluation analyzes the costs and benefits of the

proposed rulemaking to establish noise limitations for certain aircraft

operations over the Grand Canyon National Park (GCNP). The FAA is

proposing these limitations to reduce the impact of aircraft noise on

the park environment and to assist the National Park Service in

achieving its statutory mandate imposed by Public Law 100-91. Public

Law 100-91 mandates for the substantial restoration of natural quiet

and experience in GCNP. Responding to the law, this proposal would

assure the achievement of that mandate through a combination of

requirements that would limit the future use of noisier aircraft and

provide incentives for the use of quieter aircraft. This NPRM is issued

concurrently with a final rule which codifies and revises the

provisions of Special Federal Aviation Regulation (SFAR) No. 50-2,

Special Flight Rules in the Vicinity of Grand Canyon National Park.

Costs

The FAA estimates that the undiscounted cost of the proposed rule

to be $172.6 million, with a present value of $96.7 million. This cost

estimate was calculated for the 12-year period, 1997 to 2008, and would

be incurred by operators conducting airtour operations at the GCNP.

Most of this cost would result from operators having to ultimately

replace their Category A and B aircraft with Category C aircraft. Each

of the cost categories are described below. The assumptions used to

calculate the costs are explained in detail in the full regulatory

evaluation.\2\

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\2\ As required by the Office of Management and Budget (OMB),

the present value of this stream was calculated using a discount

factor of 7 percent. All dollar values are expressed in 1995

dollars.

---------------------------------------------------------------------------

The FAA has identified five cost components in the NRPM. These

components and their respective costs are explained below.

Cost of Certifying Noise Efficiency

Four aircraft--CE-180, CE-206, PA-28-180, and BHT-206-B--predate

the noise standard and, therefore, do not have certificated noise

levels. To obtain a noise level to use to compare with the GCNP noise

efficiency limit, either a computational analysis or a measurement test

is required. The estimated costs for this are $18,750 for each aircraft

type, and would occur in 1997, so the total cost would be $75,000 (net

present value, $70,000).\3\

---------------------------------------------------------------------------

\3\ While it is possible in the future that another aircraft

would be introduced into the GCNP that does not have a certified

noise level, such a situation is impossible to predict. All Category

B and C aircraft that this analysis assumes airtour operators would

convert to have certified noise levels, so no additional costs are

anticipated in the future for this cost component.

---------------------------------------------------------------------------

Cost of Phase-Out

Another cost of the NPRM is the eventual phase-out of Category A

and Category B aircraft and replacement with Category C aircraft.

Specifically, the cost represents the difference in value of existing

aircraft and their replacements and the additional or differential

expenses associated with operating the quieter aircraft.

Phase-Out of Category A for Category B Aircraft: The aircraft value

differential was calculated by subtracting the value of Category A

aircraft from the value of Category B aircraft. The operating cost

differentials were similarly calculated and added over the period 1997

to 2000. These aircraft would subsequently need to be replaced by

Category C aircraft between 2001 and 2008. The analysis assumes that

each existing Category A aircraft would be replaced by a PA-31-350 by

2000, which would then be replaced by a Caravan by 2008. The cost of

phasing out Category A for Category B aircraft (and subsequently for

Category C aircraft) is $74 million, with a present value of $42

million.

The FAA considered the option of requiring phased-out Category A

aircraft to be replaced directly with Category C aircraft instead of

allowing operators to temporarily replace Category A aircraft with

Category B aircraft. This option was rejected because requiring direct

conversion to more expensive Category C aircraft would place a major

economic burden on many small business operators during the first four

years of the phase-out (1997-2000). The FAA estimates that $72 million

more in costs would occur in this period as a result of this option

than if transition to Category B was allowed. Some operators may choose

to convert directly from Category A to Category C aircraft since it

must be done by 2008 anyway, but allowing the flexibility to convert

from A to B to Category C provides economic relief to those operators

who need it most by allowing them to spread costs over a much longer

period and generate additional revenues to offset these costs. Direct

conversion from Category A to Category C results in some small earlier

noise reductions in the Park, but both approaches lead to the same

benefits by the year 2008.

Phase-Out of Category B for Category C Aircraft: The aircraft value

differential was calculated by subtracting the value of Category B

aircraft from the value of Category C aircraft. (See full regulatory

evaluation for list of aircraft.) The operating cost differentials were

similarly calculated and added over the period 2001 to 2008. The cost

of phasing out Category B for Category C aircraft by 2008 is $62

million, with a present value of $34 million.

Cost of Non-Addition for Category A Aircraft

This non-addition cost is the cost associated with prohibiting

additions of Category A aircraft that would otherwise occur in the

absence of the proposed rule. It is the cost differential between the

price of Category B or C aircraft and Category A aircraft. From 1997 to

2000, all Category A aircraft would need to be converted to Category B

aircraft. Thereafter, all Category A aircraft would have to become

Category C aircraft. Twelve-year costs sum to $22 million with a

present value of $12 million.

Cost of Non-Addition for Category B Aircraft

Similarly, non-addition cost for Category B aircraft is the cost

associated with prohibiting Category B additions except for replacement

of Category A aircraft. It is the cost differential between the price

of Category B aircraft and a Category C aircraft had this proposed rule

not been in place. This analysis makes the same aircraft substitutions

that are shown in the table above in the section on ``Phase-Out of

Category B for Category C Aircraft.'' Total 12-year costs equal $14

million with a present value of $9 million.

Benefits

The benefits of noise reduction attributable to this rulemaking can

be broadly categorized as use and non-use benefits. Use benefits are

the benefits perceived by individuals from the direct

[[Page 69348]]

use of a resource such as hiking, rafting, or sightseeing. Non-use

benefits are the benefits perceived by individuals from merely knowing

that a resource is preserved in a given state. For example, GCNP

clearly has value to people who have not visited the park, but take

pleasure from the knowledge of its existence. It also has value to

people who may wish to visit the Park at some future date. The non-use

benefits attributable to this rulemaking have not been estimated but

are described qualitatively. The use benefits of this rulemaking have

been estimated and are presented below.

The Final Rule revising SFAR 50-2 contains certain overflight

restrictions. The benefits of those restrictions have been estimated

and are reported in the Final Rule. The NPRM would further amend SFAR

50-2 and the additional benefits are estimated here. The same

methodology and some of the same data used to estimate benefits for the

Final Rule are also used to estimate benefits in the NPRM.

Economic studies have not been conducted specifically to estimate

benefits for the NPRM. Benefits are, therefore, estimated for analogous

situations combining value estimates from existing economic studies

with site-specific information related to GCNP and other information.

Certain criteria should be applied to ensure that appropriate studies

are selected. Those criteria are:

Selected economic studies must reasonably represent the

resources to be valued in terms of physical characteristics, service

flows, user characteristics, and available substitutes;

Selected economic studies must be scientifically sound.

Studies that are either published in a peer-reviewed academic journal

or are conducted by a recognized university-associated researcher or

established consulting firm are considered to be scientifically sound;

and

Selected economic studies must use appropriate valuation

methodologies.

The site-specific information used in the benefits estimation

includes visitation data for GCNP and a visitor survey conducted to

document the visitor impacts of aircraft noise within GCNP. The

available visitation data for GCNP permits the categorization of

visitors into the following groups: backcountry users, river users, and

other visitors. ``Other visitors'' includes those sightseeing,

picnicking, pleasure driving, etc. National Park Service estimates for

the number of visitor-days in 1995 for these visitor groups are as

follows:

Number of Visitor-Days in 1995

------------------------------------------------------------------------

Visitor group Visitor days

------------------------------------------------------------------------

Backcountry............................................. 115,478

River................................................... 168,602

Other................................................... 5,517,720

---------------

Total............................................. 5,801,800

------------------------------------------------------------------------

The GCNP visitor survey indicates that these different visitor

groups are variously affected by aircraft noise (HBRS, Inc. and Harris

Miller Miller & Hanson, Inc. 1993). This survey asked respondents to

classify the interference of aircraft noise with their appreciation of

the natural quiet of GCNP as either ``not at all,'' ``slightly,''

``moderately,'' ``very much,'' or ``extremely.'' The percent of

visitors indicating these impacts is presented below by visitor group.

Visitors Affected by Aircraft Noise in Grand Canyon National Park

------------------------------------------------------------------------

Back-

country River Other

Impact visitorsa visitorsb visitors

(percent) (percent) (percent)

------------------------------------------------------------------------

Not At All............................. 41.0 45.5 76.0

Slightly............................... 15.0 16.5 11.0

Moderately............................. 13.5 10.0 4.0

Very Much.............................. 14.5 12.5 4.0

Extremely.............................. 16.0 15.5 5.0

------------------------------------------------------------------------

a Average for Summer and Fall users.

b Average for motor and oar users.

Source: HBRS, Inc. and Harris Miller Miller & Hanson, Inc. 1993.

The economic studies selected for use in the benefit estimation are

listed below. These studies value recreational activities in or near

GCNP. All dollar amounts are indexed to 1995. The implicit price

deflator for GDP was used to index all values (Survey of Current

Business, March 1996).

Visitor-Day Values

------------------------------------------------------------------------

Consumer

Activity Study \4\ surplus per

visitor-day

------------------------------------------------------------------------

Hiking in Arizona................ Martin, Russell, and $43.16

Smith 1974.

Multi-Day Rafting in Grand Canyon Boyle, Welsh, and Bishop 128.21

Natl Park. 1988.

Sightseeing in Bryce Canyon Natl Haspel and Johnson 1982. 39.71

Park.

------------------------------------------------------------------------

\4\ Reported in Walsh, Johnson, and McKean 1988.

Consumer surplus is the difference between the maximum amount a

consumer is willing to pay and what the consumer actually pays. It is a

measure of the increase in well-being gained by individuals through

participation in recreational activities.

It was assumed that these visitor-day values represent the value of

participating in the indicated activities at GCNP absent any impacts

from aircraft noise. It should be noted that these values potentially

understate the value of participation absent any impacts from aircraft

noise to the extent that they were estimated in conditions where

aircraft noise was present.

There is no economic study available that estimates the reduction

in the value of participation that is attributable to the ``slightly,''

``moderately,'' ``very much,'' or ``extremely'' impacts described in

the GCNP visitor survey. Therefore, the following reductions were

assumed. The results of a sensitivity analysis using lower percentage

reductions are reported below.

Assumed Reductions in Visitor-Day Values

------------------------------------------------------------------------

Reduction

Impact (percent)

------------------------------------------------------------------------

Slightly..................................................... 20

Moderately................................................... 40

Very Much.................................................... 60

Extremely.................................................... 80

------------------------------------------------------------------------

The total lost value for each category was calculated as the

product of the number of visitor-days, the proportion

[[Page 69349]]

of visitors affected by aircraft noise, the visitor-day value, and the

assumed proportional reduction in the visitor-day value. For example

the total lost value for river users that were moderately affected is

the product of the number of river visitor-days (168,602), the

proportion of river users that were moderately affected by aircraft

noise (10.0 percent), the visitor-day value for river use ($128.21),

and the assumed reduction in the visitor-day value given a moderate

impact (40 percent).

Based on the number of visitors to the park in each use category,

these data and assumptions imply the following total lost values from

all aircraft noise in 1995 as noted in the table below. Approximately

58 percent of these benefits were estimated to be obtained by the final

rule revising SFAR 50-2. That leaves approximately 42 percent of the

total available for this NPRM.

Total Lost Value From All Aircraft Noise in 1995

----------------------------------------------------------------------------------------------------------------

Backcountry

Impact visitors River visitors Other visitors Total

----------------------------------------------------------------------------------------------------------------

Slightly........................................... $149,509 $716,677 $4,819,884 $5,686,070

Moderately......................................... 269,116 868,700 3,505,370 4,643,186

Very Much.......................................... 433,576 1,628,812 5,258,055 7,320,443

Extremely.......................................... 637,905 2,692,969 8,763,425 12,094,299

------------------------------------------------------------

Total........................................ ........... .............. .............. 29,743,998

----------------------------------------------------------------------------------------------------------------

The benefit of the proposed rule is that portion of the total lost

value that is associated with the resulting noise reduction. Aircraft

noise modeling has produced a measures called Leq12, which is a

non-linear form. Determining a linear measurement of noise reduction

weighted by ground area over different levels requires calculation of

the antilog of the contour levels. This process produces an estimated

sound energy level that can be compared linearly over varying ground

areas. The noise reduction results for this NPRM are presented below.

Average linearized noise measure, weighted by the square miles over

which different levels, are predicted to occur according to the

following schedule:

------------------------------------------------------------------------

Noise

Year No NPRM With NPRM reduction

(percent)

------------------------------------------------------------------------

1997............................... 1,268.33 1,277.70 -0.74

2000............................... 1,268.33 1,087.83 14.23

2008............................... 1,268.33 685.96 45.92

------------------------------------------------------------------------

The 45.92% noise reduction by the year 2008 corresponds to the

finding in the environmental assessment of this proposed rule that 57.4

percent of the GCNP area will have achieved natural quiet as defined by

NPS.

The indicated reduction in aircraft noise for each year was applied

to the total lost value from all aircraft noise. Subtracted from that

application is the amount applied as estimated benefits for the final

rulemaking revising SFAR 50-2. That product yields the current use

benefit for that year.

Linear interpolation was used to estimate benefits between the

years 1997 to 2000, and 2000 to 2008. A 3 percent discount rate was

then applied to calculate the present value of use benefits over the

ten year regulatory evaluation period. The economics literature

supports a 3 percent discount rate for natural resource valuation

(e.g., Freeman 1993). Recent Federal rulemakings also support a 3

percent discount rate for natural resource valuation (61 FR 453; 61 FR

20584). The total indicated benefits represent approximately 22 percent

of the total benefits available. The resulting use benefit estimates

are presented in the following table.

Indicated Use Benefits of the Overflight NPRM

------------------------------------------------------------------------

Current

Year value Present value

------------------------------------------------------------------------

1997..................................... $(106,234) $(103,140)

1998..................................... 598,389 564,039

1999..................................... 1,279,091 1,170,549

2000..................................... 1,869,864 1,661,350

2001..................................... 2,324,027 2,004,726

2002..................................... 2,749,363 2,302,548

2003..................................... 3,145,872 2,557,881

2004..................................... 3,513,553 2,773,632

2005..................................... 3,852,408 2,952,550

2006..................................... 4,162,436 3,097,244

2007..................................... 4,443,637 3,210,178

2008..................................... 4,696,011 3,293,688

------------------------------

Total.............................. 25,485,244

------------------------------------------------------------------------

It is important to recognize significant uncertainties in this

estimation. One uncertainty relates to the percentage reductions in

visitor-day values that can be attributed to aircraft noise. It was

assumed above that there is a 20 percent reduction for visitors

affected ``slightly,'' a 40 percent reduction for visitors affected

``moderately,'' a 60 percent reduction for visitors affected ``very

much,'' and an 80 percent reduction for visitors affected

``extremely.'' In recognition of the uncertainty surrounding this

assumption, one-half of these percentage reductions were used to

calculate an alternative benefit estimate. Additionally, in recognition

of the discount rate recommended in OMB Circular A-94, alternative

benefit estimates were calculated using a 7 percent discount rate.

These alternative benefit estimates are presented below.

Alternative Use Benefits Attributable to This NPRM

[Present value, 12 years]

------------------------------------------------------------------------

Visitor day value reduction assumption Discount rate

(slightly, moderately, very much, -------------------------------

extremely) 3 percent 7 percent

------------------------------------------------------------------------

20, 40, 60, 80.......................... $25,485,000 $18,795,000

10, 20, 30, 40.......................... 12,979,473 9,572,011

------------------------------------------------------------------------

The FAA and the NPS believe that the true representation of

benefits from the proposed rule are reflected by the three percent

discount rate and the visitor day value reduction of 20%, 40%, 60%, 80%

with the resulting value of 25,485,000, and that value is used to

represent the use benefits of this proposal.

In addition to these use benefits, this rulemaking would likely

generate non-use benefits. Although the FAA and the NPS have not

attempted to estimate the magnitude of these benefits, non-use benefits

have been documented and estimated in the general proximity of the

Grand Canyon. In a study relating to the operation of Glen Canyon Dam

(Hagler Bailly Consulting 1995), annual non-use benefits in a range

from $2,286.4 million to $3,442.2 million were estimated based on a

national

[[Page 69350]]

survey. No attempt has been made to relate these non-use benefit

estimates to the potential non-use benefits of aircraft noise reduction

that would occur as a result of this proposal. However, these estimates

do suggest that potentially significant non-use benefits can be

attributed to this proposed rulemaking.

National Canyon Corridor

The GCNP Final Rule, which is being simultaneously promulgated with

this proposal, will expand one of the park's flight free zones and

eliminate the Blue 1 route. The NPRM would reopen that route

(redesignated as Blue 1A) to airtour operators, provided they use

Category C aircraft.

The FAA estimates that the revenues potentially lost from

eliminating the old Blue 1 route, and included as an average cost of

$2.3 million per year in the GCNP Final Rule, would be increasingly

recovered throughout the period 1997-2008 as a result of the proposal

as operators phase out Categories A and B aircraft and replace them

with Category C aircraft.\5\ In 1997, the FAA estimates that about 28

percent of the flights between Las Vegas and Tusayan would be conducted

using Category C aircraft and would, therefore, use the new Blue 1A

route. The remaining air tour flights between Las Vegas and Tusayan

would not include a flight through the Blue 1A route and would have a

reduced fare. This percentage would increase each year as Categories A

and B aircraft are phased out. By 2001 approximately half of the

flights between Las Vegas and Tusayan will be conducted using Category

C aircraft, and therefore, fly the Blue 1A route. By 2008, the proposed

deadline for complete phase out for Categories A and B aircraft, all

flights would be conducted using Category C aircraft.

---------------------------------------------------------------------------

\5\ See Notice of Availability of Proposed Air Tour Routes

published in the Federal Register with this NPRM.

Reduction in Revenue Loss

------------------------------------------------------------------------

Year Current value Present value

------------------------------------------------------------------------

1997.................................... $566,259 $529,214

1998.................................... 663,459 579,491

1999.................................... 754,727 616,082

2000.................................... 778,156 593,651

2001.................................... 1,180,220 841,480

2002.................................... 1,616,147 1,076,907

2003.................................... 1,987,803 1,237,904

2004.................................... 2,365,380 1,376,673

2005.................................... 2,447,181 1,331,104

2006.................................... 2,532,784 1,287,539

2007.................................... 2,757,791 1,310,207

2008.................................... 2,848,798 1,264,900

-------------------------------

Totals.................................. 20,498,704 12,045,152

------------------------------------------------------------------------

The FAA estimates that the recovered lost revenue (net of variable

operating costs) attributable to the proposed rule would increase from

$556,000 in 1997 to $2.8 million in 2008. The current values and seven

percent discounted values are shown in the table above.

The FAA estimated natural resource benefits, discounted at three

percent, for the 12-year period 1997-2008 to be $25.5 million. The FAA

also estimated non-resource benefits (increased airtour operator

profits), discounted at seven percent, for the 12-year period to be

$12.0 million. The combined total benefit of this proposal, therefore,

is estimated to be $37.5 million.

Summary of Costs and Benefits

The total quantified costs of this proposal to establish noise

limitations for certain aircraft operated in the vicinity of the GCNP

are estimated to be $172.6 million undiscounted or $96.7 million

discounted to present value.

The quantified benefits, including noise reduction and use of the

Blue 1A scenic route, are estimated to be $47.4 million undiscounted

and $37.5 million discounted to present value. In addition to

quantified benefits, there are substantial unquantified benefits as

discussed above.

However, estimates of costs and benefits of the proposal were made

primarily as an aid in evaluating the economic impacts of a phase-out

that the FAA believes is necessary to obtain substantial reductions in

aircraft noise in GCNP. The benefits justifying the restoration of

natural quiet to the park have already been established by the American

public, and that determination was carried out by their elected

representatives in enactment of the law directing that natural quiet be

restored. Based on that direction and the quantified and unquantified

costs and benefits contained in this analysis, the FAA finds this

proposal to be cost beneficial.

Alternatives

As explained in the Introduction of this regulatory evaluation, the

proposed rule has been deemed ``significant'' due to its high cost and

the impact it would have on small entities. As a result, the FAA has

identified and considered alternatives to the proposed rule.

Alternative 1 is the proposed rule. Alternative 2 is to not undertake

rulemaking at this time beyond the final rule being implemented

simultaneously with this proposal. Alternative 3 is the same as

Alternative 1, but with no interim phase-out of Category B aircraft.

Operators would presumably hold on to their aircraft until the last

minute and replace them at the end of 2000 or 2008 depending on what

type of aircraft they had.

Cost of Alternatives

A side-by-side cost comparison of Alternatives 1 and 3 is presented

in the table below. Alternative 2 would have no cost and is therefore

not included. Alternatives 1 and 3 have the same total cost because the

same type and number of aircraft would be replaced under both

alternatives. However, operators would have a longer time in which to

comply under Alternative 3 than under Alternative 1. Therefore, the

present value of the cost of that compliance would be less.

Cost Comparison of Alternatives 1 and 3

----------------------------------------------------------------------------------------------------------------

Alternative 1 Alternative 3

---------------------------------------------------

Cost categories Present Present

Total cost value Total cost value

----------------------------------------------------------------------------------------------------------------

Certified Noise Efficiency Level............................ $0.08 $0.07 $0.08 $0.07

Phase Out Category A to B................................... 74.33 42.06 74.33 33.99

Phase Out Category B to A................................... 60.92 33.49 60.92 27.05

Non-Addition Category A..................................... 21.76 11.87 21.76 9.68

[[Page 69351]]

Non-Addition Category B..................................... 14.07 8.42 14.07 7.07

---------------------------------------------------

Total................................................. 171.16 95.91 171.16 77.86

----------------------------------------------------------------------------------------------------------------

Benefits of Alternatives

The benefits of Alternative 1 have already been estimated in the

Benefits section above. There are no benefits to Alternative 2 since it

merely maintains the status quo.

Alternative 3 would require the same conversion as that required in

alternative 1, except that phase-out would not be required. As with the

cost analysis, this benefits analysis assumes that all operators of

Category A aircraft would wait until the year 2000 to convert their

aircraft to Category B. Also, it is assumed that operators would wait

until the year 2008 to convert their Category B aircraft to Category C

aircraft because there would be no mandatory phase-out of Category B

aircraft before 2008.

As with Alternative 1, the indicated reduction in aircraft noise

for each year was applied to the total lost value from all aircraft

noise. However, the indicated reduction remained constant at -0.74

percent from 1997 to 2000 and 14.23 percent from the years 2000 to

2008. In the year 2008, it is assumed the noise reduction reaches the

indicated 45.92 percent. Subtracted from the application is the amount

applied as estimated benefits for the final rule making revising SFAR

50-2. That product yields the current use benefit for that year. The

annual current use benefits are presented in the following table two

tables.

Alternative 3.--Indicated Use Benefits of the Overflight NPRM

------------------------------------------------------------------------

Current Present value 3

Year value percent

------------------------------------------------------------------------

1997..................................... $(106,234) $(103,140)

1998..................................... (103,931) (97,965)

1999..................................... (102,204) (93,531)

2000..................................... 1,869,864 1,661,350

2001..................................... 1,818,071 1,568,284

2002..................................... 1,766,278 1.479,230

2003..................................... 1,714,486 1,394,034

2004..................................... 1,662,693 1,312,545

2005..................................... 1,610,901 1,234,621

2006..................................... 1,559,108 1,160,123

2007..................................... 1,507,315 1,088,917

2008..................................... 4,696,011 3,293,688

------------------------------

Total.............................. ............ 13,898,156

------------------------------------------------------------------------

The benefits of restoring the Blue 1A route for Alternatives 1, 2,

and 3 are the same. As discussed above in the Benefits section, the

benefits of implementing this route are $12 million over the 12-year

period. When combined with the $13.9 million natural-resource benefits,

the total present value benefits of Alternative 3 would be $25.9

million.

The following table compares the costs and benefits of the three

proposals. The FAA has rejected Alternative 2 because it relies solely

on the final rule issued concurrently with this NPFM to achieve the

substantial restoration of natural quiet mandated by Congress. The

NPS's definition of substantial restoration is the situation in which

50 percent or more of the Park is free of aircraft noise at least 75

percent of the time. Based on noise estimates contained in the

environmental assessment associated with this proposal, the final rule

would only marginally achieve these goals in 1997, and would begin to

fall below the goal as activity increases in the future. The FAA

believes that substantial further reductions in aircraft noise could be

achieved by taking advantage of the advanced technology incorporated

into quieter aircraft now available. Therefore, the agency rejects

Alternative 2 in favor of one that is estimated to meet or exceed NPS

standards for the immediate future.

The FAA has rejected Alternative 3 because, while similar to the

proposal, it would impose no phase-out schedule for Category B aircraft

beyond the requirement that they discontinue operations by December 31,

2008. Imposing no phase-out schedule was considered as a way to provide

operators more flexibility in transitioning from Category B to Category

C aircraft. A cost analysis of this alternative, based on the

assumption that operators would delay phasing out Category B aircraft

as long as possible, indicated that there would be a cost savings to

operators only in that investment in some Category C aircraft would be

delayed. On the other hand, the benefits of less aircraft noise in the

Park would also be less during the transition period. Further, if

operators actually did delay the phase-out until the last year, they

would probably not be able to find suitable replacement aircraft or

would have some other reason for requesting an extension of time. The

FAA's experience in other rulemaking actions requiring a transition is

that most operators do not wait until the deadline. Instead, they

develop their own transition schedules. Based on the above, the FAA

decided that establishing a transition schedule as contained the

proposal would provide for a phase-out that will assure early benefits

and can be effectively monitored. Therefore, the Agency rejects

Alternative 3.

Alternatives Costs and Benefits Comparison

[Millions]

------------------------------------------------------------------------

Present Present Benefit

value value cost

costs benefits ratio

------------------------------------------------------------------------

Alternative 1............................. $95.91 $37.5 .39

Alternative 2............................. 0.0 0.0 N/A

Alternative 3............................. 77.86 25.9 .33

------------------------------------------------------------------------

Initial Regulatory Flexibility Analysis

By both law and executive order, Federal regulatory agencies are

required to consider the impact of proposed regulations on small

entities. Executive Order 12866 ``Regulatory Planning and Review'',

dated September 30, 1993, states that:

Each agency shall tailor its regulations to impose the least burden

on society, including individuals, businesses of different sizes, and

other entities (including small communities and governmental entities),

consistent with obtaining the regulatory objectives, taking into

account, among other things, and to the extent practicable, the costs

of cumulative regulations.

The 1980 ``Regulatory Flexibility Act'' (RFA) requires Federal

agencies to prepare an initial regulatory flexibility analysis of any

notice of proposed rulemaking that will have a significant economic

impact on a substantial number of small entities. The definition

[[Page 69352]]

of small entities and guidance material for making determinations

required by the RFA are contained in the Federal Register [47 FR 32825,

July 29, 1982]. Federal Aviation Administration (FAA) order 2100.14A

outlined the agency's procedures and criteria for implementing the RFA.

With respect to this proposed rule, a ``small entity'' is a

commercial sightseeing operator that for all practical purposes owns or

operates nine or fewer aircraft. A significant economic impact on a

small entity is defined as an annualized net compliance cost to such a

small commercial sightseeing operator. In the case of scheduled

operators of aircraft for hire having less than 60 passenger seats, a

``significant economic impact'' or cost threshold, is defined as an

annualized net compliance cost level that exceeds $69,800; for

unscheduled operators the threshold is $4,900. A substantial number of

small entities is defined as a number that is more than one-third of

the small commercial sightseeing operators (but not less than eleven

operators) subject to the proposed rule.

The Federal Aviation Administration has determined that this

proposal could have a significant economic impact on all commercial

sightseeing operators conducting flights within Grand Canyon National

Park and therefore has prepared this initial regulatory flexibility

analysis. The analysis, structured in accordance with section 603 of

the RFA, requires the following:

1. Why FAA action is being considered.

2. Statement of the objectives and legal basis for the proposed

rule.

3. Description of and estimated number of small entities affected.

4. Projected reporting, recordkeeping, and other compliance

requirements of the proposed rule.

5. Any relevant Federal rules which may duplicate, overlap or

conflict with the proposed rule.

Why FAA Action is Being Considered: The proposal to establish noise

limitations for certain aircraft operations in the vicinity of the

Grand Canyon National Park stems from the need to further reduce the

impact of aircraft noise on the park environment and assist the

National Park Service in achieving its statutory mandate imposed by

Public Law 100-91 to provide for the substantial restoration of natural

quiet and experience in the Grand Canyon National Park.

Statement of the Objectives and Legal Basis for the Proposed Rule:

In 1987, Congress enacted Public Law (Pub. L.) 100-91, commonly known

as the National Parks Overflights Act (the Act). The Act stated, in

part, that noise associated with aircraft overflights at GCNP was

causing a ``significant adverse effect on the natural quiet and

experience of the park and current aircraft operations at the Grand

Canyon National Park have raised serious concerns regarding public

safety, including concerns regarding the safety of park users.''

Public Law 100-91 requires the Department of the Interior to submit

to the FAA recommendations to protect resources in the Grand Canyon

from adverse impacts associated with aircraft overflights. The law

mandated that the recommendations: (1) Provide for substantial

restoration of the natural quiet and experience of the park and

protection of public health and safety from adverse effects associated

with aircraft overflights; (2) with limited exceptions, prohibit the

flight of aircraft below the rim of the canyon; and (3) designate

flight-free zones except for purposes of administration and emergency

operations. In December of 1987, the DOT transmitted its ``Grand Canyon

Aircraft Management recommendations'' to the FAA, which included both

rulemaking and nonrulemaking actions.

On May 27, 1988, the FAA issued SFAR No. 50-2 revising the

procedures for operation of aircraft in airspace above the Grand Canyon

(53 FR 20264, June 2, 1988). The SFAR, among other things, limited the

areas for aircraft operations by establishing special flight routes for

commercial operators. Since that time, a substantial amount of public

debate has taken place regarding the effect of aircraft noise on the

Grand Canyon's environment. The debate and the objective of the

proposal is more thoroughly discussed in the preamble of this proposed

rulemaking.

On June 15, 1995, the FAA published a final rule that extended the

provisions of SFAR No. 50-2 to June 15, 1997 (60 FR 31608). This action

allowed the FAA sufficient time to review thoroughly the NPS

recommendations as to their impact on the safety of air traffic over

GCNP, and to initiate and complete any appropriate rulemaking action.

On September 16-20, 1996, in Scottsdale, Arizona, and Las Vegas,

Nevada, the FAA held public meetings to obtain additional comment on

the NPRM. entitled ``Special Flight Rules in the Vicinity of Grand

Canyon National Park,'' and on the draft environmental assessment that

accompanied that proposal. Comments and the transcripts of these

meetings have been placed in rulemaking docket No. 28537 for Notice 96-

11.

Description and Estimated Number of Small Entities Affected: The

proposed rulemaking will affect commercial sightseeing operators

conducting flights over the Grand Canyon National Park under 14 CFR

part 135. These commercial operators provide sightseeing tours of the

Grand Canyon over the four flight zones established by SFAR 50-2. FAA

data shows that in 1995, there were 26 potentially affected small

commercial sightseeing operators, each owning, but not necessarily

operating 9 or fewer aircraft. These operators owned a total of 70

aircraft and the average fleet consisted of about 3 airplanes. The FAA

estimated that 26 operators, which are also small entities, will be

impacted by the proposed rules.

Projected Reporting, Recordkeeping, and Other Compliance

Requirements of the Proposed Rule: The proposal would not require

affected small commercial sightseeing operators to maintain and report

additional information.

The proposed rule would require that operators phaseout noisier

aircraft. The proposed rule would allow B category aircraft to replace

phased out A category aircraft.

Any Relevant Federal Rules Which May Duplicate, Overlap or Conflict

with the Proposed Rule: There are no relevant Federal rules which will

duplicate, overlap or conflict with the proposed rule.

Cost of Compliance to Small Entities

The FAA has determined that four aircraft models currently

operating in GCNP predate FAA noise standards and therefore do not have

certificated noise levels. To obtain a level to use to compare with the

Grand Canyon National Park noise efficiency limit may require analysis

or a measurement test. Only four aircraft total operating at the Grand

Canyon National Park (CE 180, CE 206, PA-28-180, and BT-206-B), do not

have certificated noise levels. The cost per analysis or test is

$18,750 or $2670 annualized at 7 percent over 10 years. In no situation

would a substantial number of small operators be significantly impacted

because the annualized cost is below even the lowest threshold for

unscheduled operators and no operator owns more than one of these

aircraft.

To calculate the annualized cost impact on a small operator of the

phaseout schedule, the FAA in the regulatory evaluation determined the

cost impact on operators by aircraft type. That is, given the fleet mix

of a particular operator, the FAA calculated the cost of replacing a

given noncompliant aircraft with a complaint one. The incremental

annualized fixed

[[Page 69353]]

and variable costs of replacing noncompliant aircraft with compliant

aircraft is shown in the following table.

The FAA has determined that, after multiplying the annualized

incremental cost per aircraft type by the number of aircraft that

operators currently own/or operate, 23 small entities would be

significantly impacted under the guidelines outlined earlier.

Therefore, a substantial number of operators affected by this proposed

requirement (which is more than one-third of all GCNP commercial

sightseeing operators) would incur a significant cost impact (See table

in full regulatory evaluation.).

Description of Alternative Actions

Section 603(c) of the RFA requires that each initial regulatory

flexibility analysis contain a description of any feasible alternatives

to the proposed rule that would accomplish the stated objectives of

applicable statutes and that minimizes any significant economic impact

of the proposed rule on small entities.

The FAA and the NPS have made extensive efforts, including the

public meeting at Flagstaff, to determine the optimal action to reduce

aircraft noise and provide for the substantial restoration of natural

quiet in the GCNP. In addition to this proposed rule's phaseout of

operations of certain types of aircraft, the FAA and the NPS considered

two other alternatives, described below.

Alternative Two

Under this alternative, the FAA would not issue an NPRM phasing out

noisier aircraft at this time. Instead, the FAA would adopt an approach

that would ``wait-and-see'' the extent to which promulgation of part

93, subpart U--Special Flight Rules in the Vicinity of Grand Canyon

National Park, AZ, would reduce aircraft noise and provide for

substantial restoration of natural quiet in the GCNP. Promulgation of

part 93, subpart U, issued concurrently with this NPRM, will reduce

aircraft noise in the park by establishing new and modifying existing

flight-free zones and enlarging the Special Flight Rules Area.

Quieter, generally larger, aircraft are available, however, that

would restore more of the natural quiet in the park. Based on an

extensive review of all current information available, the FAA has

concluded that the use of these quieter aircraft is necessary to

reducing noise substantially more toward natural quiet, and that

initiating a phase-out of noisier aircraft immediately will

significantly contribute to achieving natural quiet goals. Therefore,

the FAA rejects this alternative.

Alternative Three

Under this alternative, Category A aircraft would be banned after

December 31, 2000, and Category B aircraft would be banned after

December 31, 2008, just as in the proposal, but an interim compliance

schedule would not be implemented to phase out Category B aircraft

between 2001 and 2008. Although operators of Category B aircraft could

replace their aircraft with Category C aircraft before the end of 2008,

there would be no requirement to do so.

This alternative could postpone a further reduction in aircraft

noise and postpone restoration of the natural quiet in the park during

the period 2001-2008. Therefore, the FAA rejects this alternative.

International Trade Impact Assessment

The FAA has determined that the proposed rulemaking will not affect

non-U.S. operators of foreign aircraft operating outside the United

States or U.S. trade. It could however, have an impact on commercial

sightseeing at GCNP, much of which is foreign.

The United States Air Tour Association estimates that 60 percent of

all commercial sightseeing tourists in the United States are foreign.

The Las Vegas FSDO, however, believes this estimate to be considerably

higher at GCNP, perhaps as high as 90 percent. The FAA cannot put a

dollar value on the portion of the potential loss in commercial

sightseeing revenue associated with the loss of foreign tour dollars.

Federalism Implications

The regulations herein would not have substantial direct effects on

the states, on the relationship between the national government and the

states, or on the distribution of power and responsibilities among the

various levels of government. Therefore, in accordance with Executive

Order 12866, it is determined that this rule does not have sufficient

federalism implications to warrant the preparation of a Federalism

Assessment.

Paperwork Reduction Act

In accordance with the Paperwork Reduction Act of 1995 (Pub. L.

104-13), there are no requirements for information collection

associated with the proposed regulation.

Conclusion

For the reasons set forth above, the FAA has determined that this

proposed rule is a significant regulatory action under Executive Order

12866. In addition, the FAA certifies that this proposal would have a

significant economic impact, positive or negative, on a substantial

number of small entities under the criteria of the Regulatory

Flexibility Act. This proposed rule is considered significant under DOT

Regulatory Policies and Procedures.

List of Subjects in 14 CFR Part 93

Air traffic control, Airports, Navigation (Air), Reporting and

recordkeeping requirements.

The Proposed Amendment

For the reasons set forth above, the Federal Aviation

Administration proposes to amend 14 CFR part 93 as follows:

PART 93--SPECIAL AIR TRAFFIC RULES AND AIRPORT TRAFFIC PATTERNS

1. The authority citation for part 93 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40103, 40106, 40109, 40113, 44502,

44514, 44701, 44719, 46301.

Sec. 93.305 [Amended]

2. Section 93.305 is amended by adding before the period at the end

of paragraph (c) the words: ``and not including the following airspace

designated as the National Canyon corridor: that airspace one mile on

either side of a line extending from Lat. 36 deg.08'43'' Long.

113 deg.09'19'' to Lat. 36 deg.15'30'', Long. 112 deg.51'07'' to Lat.

36 deg.14'38'', Long. 112 deg.45'56'' to Lat. 36 deg.18'17'', Long.

112 deg.42'22'' to Lat. 36 deg.17'49'', Long. 112 deg.39'54'' to Lat.

36 deg.12'36'', Long. 112 deg.34'120'' to Lat. 36 deg.08'12'', Long.

112 deg.34'36'' then back to the Blue One Direct Route at Havatagvitch

Canyon Point.

3. Section 93.306 is added to read as follows:

Sec. 93.306 Operation of GCNP Category C Aircraft in National Canyon

Corridor.

No person may operate an aircraft within the National Canyon

Corridor within the Special Flight Rules Area unless the aircraft is a

commercial sightseeing operation aircraft that meets the GCNP Category

C aircraft standard, as defined in Sec. 93.319.

Sec. 93.307 [Amended]

4. Section 93.307 is amended by adding at the end of the section

after (b)(2)(iii) a new paragraph (b)(3) to read as follows:

* * * * *

(b) * * *

(3) GCNP Category C aircraft in the National Canyon Corridor. 7,500

feet MSL.

[[Page 69354]]

Sec. 93.316 [Amended]

5. Section 93.316 is amended by removing paragraph (b) and removing

the paragraph designation ``(a)'' from the remaining paragraph.

6. Section 93.319 is added to read as follows:

Sec. 93.319 Noise limitations for commercial sightseeing flights.

(a) Definitions. For the purpose of this section only--

Base level for Category A aircraft means the total number of

category A aircraft listed on a certificate holder's operations

specifications on December 31, 1996, and for Category B aircraft means

the total number of Category B aircraft listed on a certificate

holder's operations specifications on December 31, 2000, for use in

commercial sightseeing operations within the SFRA.

GCNP Category A aircraft means an aircraft that has not been shown

to comply with the GCNP Category B or GCNP Category C noise limit in

appendix B of this part.

GCNP Category B aircraft means an aircraft that has been shown to

comply with the GCNP Category B noise limit in appendix B of this part,

but not the GCNP Category C noise limit in appendix B of this part.

GCNP Category C aircraft means an aircraft that has been shown to

comply with the GCNP Category C noise limit in appendix B of this part.

New Entrant Operator means any person that was not authorized to

conduct commercial sightseeing operations within the SFRA as of

December 31, 1996.

(b) GCNP Category A Aircraft. After [Effective date of final rule],

no certificate holder may operate a greater number of GCNP Category A

aircraft in commercial sightseeing operations within the SFRA than the

number of aircraft listed on that certificate holder's operations

specifications on December 31, 1996, for use in commercial sightseeing

operations within the SFRA. After December 31, 2000, no certificate

holder may operate a GCNP Category A aircraft in commercial sightseeing

operations within the SFRA.

(c) GCNP Category B Aircraft. (1) After [Effective date of final

rule], no certificate holder may operate a greater number of GCNP

Category B aircraft in commercial sightseeing operations within the

SFRA than the number of aircraft listed on that certificate holder's

operations specifications on December 31, 1996, for use in commercial

sightseeing operations within the SFRA, unless the aircraft was added

to the certificate holder's operations specifications after December

31, 1996, and on or before December 31, 2000, as a replacement for a

GCNP Category A aircraft that was listed on that certificate holder's

operations specifications on December 31, 1996, for use in commercial

sightseeing operations within the SFRA.

(2) After December 31, 2002, no certificate holder may operate more

than 75 percent of the base level number of GCNP Category B aircraft in

commercial sightseeing operations within the SFRA. Calculations

resulting in fractions may be rounded to permit the continued operation

of the next whole number of Category B aircraft.

(3) After December 31, 2004, no certificate holder may operate more

than 50 percent of the base level number of GCNP Category B aircraft.

Calculations resulting in fractions may be rounded to permit the

continued operation of the next whole number of Category B aircraft.

(4) After December 31, 2006, no certificate holder may operate more

than 25 percent of the base level number of GCNP Category B aircraft.

Calculations resulting in fractions may be rounded to permit the

continued operation of the next whole number of Category B aircraft.

(5) After December 31, 2008, no certificate holder may operate a

GCNP Category B aircraft in commercial sightseeing operations within

the SFRA.

(d) GCNP Category C Aircraft. Except for GCNP Category B aircraft

added to the certificate holder's operations specifications as a

replacement aircraft as authorized in paragraph (c)(1) of this section,

no certificate holder may add an aircraft to its operations

specifications for use in commercial sightseeing operations within the

Special Flight Rules Area unless the aircraft is a GCNP Category C

aircraft.

(e) New entrant operators. After [insert effective date of final

rule], no new entrant operator may conduct commercial sightseeing

operations within the SFRA unless the aircraft used in those operations

is a GCNP Category C aircraft.

7. Appendix B is added to part 93 to read as follows:

Appendix B--GCNP Aircraft Noise Limits

This appendix contains procedures for determining GCNP aircraft

noise limits for each aircraft subject to Sec. 93.319 determined

during the noise certification process as prescribed under part 36

of this chapter. Where no certificated noise level is available, an

alternative measurement procedure may be approved by the

Administrator.

1. GCNP Category B Noise Limit

A. For helicopters with a flyover noise level obtained in

accordance with the measurement procedures prescribed in Appendix H

of 14 CFR part 36, the limit is 84 dB for helicopters having 2 or

fewer passenger seats, increasing at 3 decibels per doubling of the

number of passenger seats for helicopters having 3 or more passenger

seats. The limit at number of passenger seats of 3 or more can be

calculated by the formula:

EPNL(H-Cat. B)=84 +101og (# PAX seats/2) dB

B. For helicopters with a flyover noise level obtained in

accordance wit the measurement procedures prescribed in Appendix J

of 14 CFR part 36, the limit is 81 dB for helicopters having 2 or

fewer passenger seats, increasing at 3 decibels per doubling of the

number of passenger seats for helicopters having 3 or more passenger

seats. The limit at number of passenger seats of 3 or more can be

calculated by the formula;

SEL(J-Cat. B)=81 +10log(# PAX seats/2) dB

C. For propeller-driven airplanes with a measured flyover noise

level obtained in accordance with the measurement procedures

prescribed in Appendix F of 14 CFR part 36 without the performance

correction defined in Sec. F35.201(c), the limit is 73 dB for

airplanes having 2 or fewer passenger seats, increasing at 3

decibels per doubling of the number of passenger seats for airplanes

having 3 or more passenger seats. The limit at number of passenger

seats of 3 or more can be calculated by the formula:

LAmax (F-Cat. B)=73 +101og(# PAX seats/2) dB

D. In the event that a flyover noise level is not available in

accordance with Appendix F of 14 CFR part 36, the noise limit for

propeller-driven airplanes with a takeoff noise level obtained in

accordance with the measurement procedures prescribed in Appendix G

is 78 dB for airplanes having 2 or fewer passenger seats, increasing

at 3 decibels per doubling of the number of passenger seats for

airplanes having 3 or more passenger seats. The limit at number of

passenger seats of 3 or more can be calculated by the formula:

LAmax(G-Cat. B)=78+10log (# PAX seats/2) dB

2. GCNP Category C Noise Limit

A. For helicopters with a flyover noise level obtained in

accordance with the measurement procedures prescribed in Appendix H

of 14 CFR part 36, the limit is 80 dB for helicopters having 2 or

fewer passenger seats, increasing at 3 decibels per doubling of the

number of passenger seats for helicopters having 3 or more passenger

seats. The limit at number of passenger seats of 3 or more can be

calculated by the formula:

EPNL(H-Cat. C)=80+10log (# PAX seats/2) dB

B. For helicopters with a flyover noise level obtained in

accordance with the measurement procedures prescribed in Appendix J

of 14 CFR part 36, the limit is 77 dB for helicopters having 2 or

fewer passenger seats, increasing at 3 decibels per doubling of the

number of passenger seats for helicopters having 3 or more passenger

seats. The limit at number of passenger seats of 3 or more can be

calculated by the formula:

SEL(J-Cat. C)=77+10log (# PAX seats/2) dB

[[Page 69355]]

C. For propeller-driven airplanes with a measured flyover noise

level obtained in accordance with the measurement procedures

prescribed in Appendix F of 14 CFR part 36 without the performance

correction defined in Sec. F35.201(c), the limit is 69 dB for

airplanes having 2 or fewer passenger seats, increasing at 3

decibels per doubling of the number of passenger seats for airplanes

having 3 or more passenger seats. The limit at number of passenger

seats of 3 or more can be calculated by the formula:

LAmax(F-Cat. C)=69+10log (# PAX seats/2) dB

D. In the event that a flyover noise level is not available in

accordance with Appendix F of 14 CFR part 36, the noise limit for

propeller-driven airplanes with a takeoff noise level obtained in

accordance with the measurement procedures prescribed in Appendix G

is 74 dB for airplanes having 2 or fewer passenger seats, increasing

at 3 decibels per doubling of the number of passenger seats for

airplanes having 3 or more passenger seats. The limit at number of

passenger seats of 3 or more can be calculated by the formula:

LAmax(G-Cat. C)=74+10log (# PAX seats/2) dB

Issued in Washington, DC, on December 24, 1996.

James D. Erickson,

Director, Office of Environment and Energy.

[FR Doc. 96-33145 Filed 12-30-96; 8:45 am]

BILLING CODE 4910-13-M