Aging Airplane Safety

Federal RegisterApr 2, 1999

Ask Donna

What actually matters in this document.

Text

SUMMARY: The FAA proposes to require all airplanes operated under part

121 of Title 14, Code of Federal Regulations (14 CFR), all U.S.-

registered multiengine airplanes operated under 14 CFR part 129, and

all multiengine airplanes used in scheduled operations under 14 CFR

part 135 to undergo records reviews and inspections by the

Administrator after their 14th year in service to ensure that the

maintenance of these airplanes' age-sensitive parts and components has

been adequate and timely. The FAA also proposes to permit certain

representatives of the Administrator to conduct these inspections. The

proposed rule also would prohibit operation of these airplanes after

specified deadlines unless damage-tolerance-based inspections and

procedures are included in their maintenance or inspection program.

This proposal represents a critical step toward compliance with the

Aging Aircraft Safety Act of 1991. It would help ensure the continuing

airworthiness of aging airplanes operating in air transportation by

applying modern damage-tolerance analysis and inspection techniques to

older airplane structures that were certificated before such techniques

were available, and through mandatory aging aircraft records reviews

and inspections to be performed by the Administrator.

The Aging Airplane Safety NPRM published on October 5, 1993 (58 FR

51944) is withdrawn.

DATES: Comments must be received on or before August 2, 1999.

ADDRESSES: Comments on this proposed rulemaking should be mailed or

delivered, in triplicate, to: U.S. Department of Transportation

Dockets, Docket No. FAA-1999-5401, 400 Seventh St. SW., Room Plaza 401,

Washington, DC 20590. Comments also may be submitted electronically to

the following Internet address: [email protected] Comments may be

filed and/or examined in Room Plaza 401, between 10:00 a.m. and 5:00

p.m. weekdays except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Frederick Sobeck, Aircraft Maintenance

Division (AFS-300), Flight Standards Service, Federal Aviation

Administration, 800 Independence Avenue SW., Washington, DC 20591,

telephone (202) 267-7355.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the

proposed rule by submitting such written data, views, or arguments as

they desire. Comments relating to the environmental, energy,

federalism, or economic impact that might result from adopting the

proposals in this notice also are invited. Substantive comments should

be accompanied by cost estimates. Comments must identify the regulatory

docket or notice number and be submitted in triplicate to the Rules

Docket address specified above.

All comments received, as well as a report summarizing each

substantive public contact with FAA personnel on this rulemaking, will

be filed in the docket. The docket is available for public inspection

before and after the comment closing date.

All comments received on or before the closing date will be

considered by the Administrator before taking action on this proposed

rulemaking. Late-filed comments will be considered to the extent

practicable. The proposals contained in this notice may be changed in

light of the comments received.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this notice must include a pre-addressed,

stamped postcard with those comments on which the following statement

is made: ``Comments to Docket No. FAA-1999-5401.'' The postcard will be

date stamped and mailed to the commenter.

Availability of NPRMs

Using a modem and suitable communications software, an electronic

copy of this document may be downloaded from the FAA regulations

section of the FedWorld electronic bulletin board service (telephone:

(703) 321-3339), the Federal Register's electronic bulletin board

service (telephone: (202) 512-1661), or the FAA's Aviation Rulemaking

Advisory Committee Bulletin Board service (telephone: (202) 267-5948).

Internet users may reach the FAA's web page at http://www.faa.gov/

avr/arm/nprm/nprm.htm or the Government Printing Office's webpage at

http://www.access.gpo.gov/nara for access to recently published

rulemaking documents.

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

to the Federal Aviation Administration, Office of Rulemaking, ARM-1,

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

267-9680. Communications must identify the notice number or docket

number of this NPRM.

Persons interested in being placed on the mailing list for future

NPRMs should request from the above office a copy of Advisory Circular

No. 11-2A, Notice of Proposed Rulemaking Distribution System, which

describes the application procedure.

Background

Statutory Requirement

In October 1991, Congress enacted Title IV of Public Law 102-143,

the ``Aging Aircraft Safety Act of 1991'' (AASA), to address aging

aircraft concerns. The AASA was subsequently codified as section 447717

of Title 49, Unites States Code (49 U.S.C.).

Section 44717 of 49 U.S.C. instructs the Administrator to

``prescribe regulations that ensure the continuing airworthiness of

aging aircraft.'' That section also requires the Administrator to

``make inspections, and review the maintenance and other records, of

each aircraft an air carrier uses to provide air transportation.'' The

records reviews and inspections would be those necessary to ``enable

the Administrator to decide whether the aircraft is in safe condition

and maintained properly for operation in air transportation.'' Section

44717 of 49 U.S.C. specifies that these inspections and reviews must be

carried out as part of each aircraft's heavy maintenance check

conducted ``after the 14th year in which the aircraft has been in

service.'' It also states that the air carrier must ``demonstrate to

the Administrator, as part of the inspection, that maintenance of the

aircraft's age-sensitive parts and components has been adequate and

timely enough to ensure the highest degree of safety.''

Section 44717 of 49 U.S.C. further states that the rule issued by

the Administrator must require an air carrier to make its aircraft, as

well as any records about the aircraft that the Administrator may

require to carry out the review, available for inspection as necessary

to comply with the rule. It also states that the Administrator must

establish procedures to be followed for carrying out such an

inspection.

[[Page 16299]]

Aging Airplane Safety Notice of Proposed Rulemaking, 1993

On October 5, 1993, the FAA published Notice No. 93-14, ``Aging

Airplane Safety'' (58 FR 51944). The proposals contained in that notice

would have required operator certification of aging airplane

maintenance actions and would have established a framework for the

Administrator to impose operational limits on certain airplanes. Once

an airplane reached those limits, additional maintenance actions would

be necessary, such as inspections or parts replacements, for the

airplane to continue operating. Operational limits would have been

established in a separate rulemaking.

Other specific proposals related to operator certification of aging

airplane maintenance actions were included in the notice. Those

proposals included: (1) A definition of the terms ``heavy maintenance

check'' (HMC) and ``years in service''; (2) a requirement for

certificate holders to establish an HMC interval for each airplane they

operate; (3) a requirement for certificate holders to make a

maintenance record at the start of each airplane's 15th year in service

and at all subsequent HMCs to certify that the airplane met all

maintenance program requirements; and (4) a requirement for certificate

holders to notify the FAA at least 30 days before the start of an

airplane's HMC.

A number of commenters objected to certain provisions contained in

the notice. Many commenters indicated that current rules already enable

the Administrator to determine that an aircraft meets all maintenance

program requirements; therefore, they asserted that additional

rulemaking was unnecessary. Several commenters opposed the required 30-

day notice proposal because the current regulations provide the FAA

with sufficient means to determine the date of an aircraft's next

required inspection. Several commenters also were concerned that the

definition of ``heavy maintenance check'' was too broad.

A number of commenters opposed the concept of an operational limit

unless the FAA specified the requirements used to establish and extend

those limits. Finally, some commenters suggested that the FAA exclude

airplanes already having damage-tolerance-based supplemental inspection

programs (SIPs) from the operational limit requirement.

Withdrawal of Notice

After further review, and taking into consideration public

comments, the Aging Airplane Safety NPRM, Notice No. 93-14 (58 FR

51944, October 5, 1993) is hereby withdrawn.

General Discussion

Historical Perspective

The continued airworthiness of aircraft structure is significantly

affected by age-related fatigue damage. Evidence to date suggests that

when all critical structure are included, damage-tolerance-based

inspections and procedures provide the best approach to address

aircraft fatigue.

An underlying principle of damage tolerance is that the initiation

and growth of structural fatigue damage can be anticipated with

sufficient precision to allow damage-tolerance-based inspections and

procedures to detect damage before it reaches a size that affects an

airplane's airworthiness. When damage is discovered, airworthiness is

maintained by repairing the airplane before further flight.

Early fatigue requirements, such as ``fail-safe'' regulations, did

not provide for timely inspection of an aircraft's critical structure

to ensure that damaged or failed components could be dependably

identified and then repaired or replaced before a hazardous condition

developed. In 1978, the damage-tolerance concept was adopted for

transport category airplanes as an amendment to 14 CFR 25.571 by

Amendment No. 25-45 (43 FR 46238). That amended rule required damage-

tolerance analysis as part of the type design of transport category

airplanes for which application was received after October 5, 1978. On

May 6, 1981, the FAA published Advisory Circular (AC) 91-56,

``Supplemental Structural Inspection Program for Large Transport

Category Airplanes,'' guidance material based on the amended rule for

existing designs. Using the guidance provided in AC 91-56, many

manufacturers of large transport category airplanes (airplanes of more

than 75,000 pounds) developed SIPs for their existing models.

Beginning in 1984, the FAA issued a series of airworthiness

directives (ADs) requiring the operators of those airplanes to

incorporate the SIPs into their maintenance programs. SIPs provide

inspections and procedures that are based on damage-tolerance

principles.

On August 6, 1993, the FAA revised the airworthiness standards for

small metallic airplanes to incorporate Amendment No. 23-45 (58 FR

42163) into 14 CFR part 23. Those revisions provided an option to use

damage-tolerance-based inspections and procedures as a means for

achieving continued airworthiness of newly certificated normal,

utility, acrobatic, and commuter category airplanes. On February 9,

1996, the FAA revised part 23 by Amendment No. 23-48 (61 FR 5148) to

require damage-tolerance-based inspections and procedures on all newly

certificated commuter category airplanes.

Other airplanes were not affected by the described rule changes and

thus do not have prescribed damage-tolerance-based inspections and

procedures. These airplanes fall into four basic categories: (1)

Airplanes with non-damage-tolerance-based SIPs, based solely on service

history, as prescribed in AC No. 91-60, ``The Continued Airworthiness

of Older Airplanes''; (2) airplanes that were certificated with design-

life limits on the entire airplane or on major components such as the

wing, empennage, or fuselage; (3) airplanes that were designed to

``fail-safe'' criteria to comply with fatigue requirements; and (4)

airplanes that were certificated with limited consideration being given

to metal fatigue.

This Proposal

This proposed rule responds to the provisions of 49 U.S.C. 44717,

which requires the Administrator to ``prescribe regulations that ensure

the continuing airworthiness of aging aircraft * * * [and] to make

inspections and review the maintenance and other records of each

aircraft an air carrier uses to provide air transportation that the

Administrator decides may be necessary to enable the Administrator to

decide whether the aircraft is in safe condition and maintained

properly for operation in air transportation.''

As a result of requirements stipulated in 49 U.S.C. 44717, the FAA

proposes to prohibit the operation of certain airplanes in scheduled

service unless the Administrator or the Administrator's designee has

determined that maintenance of the aircraft's age-sensitive parts and

components has been adequate and timely. All airplanes operating under

part 121, all U.S.-registered multiengine airplanes operating under

part 129, and all multiengine airplanes conducting scheduled operations

under part 135 would be affected.

Air carriers would be required to make each airplane and certain

records related to the maintenance of age-sensitive components of the

airplane available to the Administrator. Also, each affected airplane

would be prohibited from operating unless damage-tolerance-based

inspections and procedures are included in the

[[Page 16300]]

maintenance or inspection program used on each airplane in accordance

with a specified schedule. Damage-tolerance-based inspections and

procedures would be required on all affected airplanes no later than

December 20, 2010.

The airplanes affected by this proposed rule transport a

significant proportion of those passengers carried in scheduled

passenger service and are the most prevalent airplanes operated in such

service.

This notice does not propose requirements for rotorcraft or single-

engine airplanes, nor does it propose requirements for on-demand

passenger- or cargo-carrying operations under 14 CFR part 135. The

scope of this proposal includes the preponderance of aircraft the

Congress intended to cover under the AASA. Furthermore, the FAA

anticipates that the resource-intensive implementation of the proposed

aircraft and records inspection provisions may be difficult to

administer initially, but that FAA (and designee) resources, in the

future, will have the capacity to oversee additional fleets of

aircraft.

Thus, in a future notice, the FAA will propose aging aircraft

requirements necessary to cover the operation of all the other aircraft

used by air carriers to provide air transportation. For the purpose of

developing those proposals, the FAA may consider the information (e.g.,

documents in public docket) it develops for the rule proposed in this

notice. It is possible that those future proposals could be similar to

the requirements proposed in this notice; however, because of the

differences in the designs, operations, and maintenance of those

aircraft, differences between this notice and the future proposals are

likely.

Congress also instructed the Administrator to encourage governments

of foreign countries and relevant international organizations to

develop programs addressing aging aircraft concerns. Most foreign air

carriers and foreign persons engaged in common-carriage operations have

maintenance program requirements adopted by their governments. The FAA

issues the airworthiness certificates for U.S.-registered airplanes. By

including part 129 in this proposed rule, foreign air carriers and

foreign persons operating U.S.-registered multiengine aircraft within

or outside the United States would be required to include damage-

tolerance-based inspections and procedures in their maintenance

programs and be subject to aging aircraft records reviews and

inspections. This action forms a portion of the FAA's response to the

AASA by helping to ensure the continued airworthiness of aging U.S.-

registered airplanes operated worldwide.

This proposal also would revise current 14 CFR 183.33(a) to expand

the authority of the Designated Airworthiness Representative (DAR). The

DAR would be authorized to conduct the proposed records reviews and

inspections on behalf of the Administrator. When this proposal becomes

a final rule, the FAA intends to recommend that the International Civil

Aviation Organization (ICAO) and the Joint Aviation Authorities (JAA)

consider making similar changes to their recommended practices and

requirement.

Inspections

The FAA intends to verify that each operator has records to show

that they have accomplished all required maintenance tasks, as well as

the damage-tolerance-based inspections and procedures that would be

required by this proposal. The FAA would validate that these records

are correct for each affected airplane during the records review and

inspection required by this proposed rule.

Section 44717 of 49 U.S.C. specifies that the records reviews and

inspections be carried out as part of each aircraft's heavy maintenance

check after the 14th year in service. For airplanes that have already

completed 14 years in service, the proposal would require the first

records review and inspection within 3 to 5 years of the effective date

of the rule. This proposal would generally require the first records

review and inspection to be accomplished no later than 5 years after

the 14th year in service.

The FAA realizes that the first inspection required 5 years after

the 14th year in service may not be consistent with current operator

maintenance schedules. As a result, the records reviews and inspections

carried out by the Administrator or the Administrator's designee may

significantly affect these maintenance schedules, because the reviews

and inspections may not coincide with current maintenance schedules.

In formulating this proposal, the FAA considered options for

setting repeat intervals. Among those considered were the heavy

maintenance check interval, heavy maintenance visit interval, or the

``letter check'' (e.g., ``C'', ``D'', or ``E'') interval or other

equivalent check interval an operator may use. The FAA reviewed

variabilities in the parameters used by operators to carry out

scheduled maintenance requirements such as flight hours, calendar time,

or a combination of both. The FAA also considered the phasing and

segmenting of heavy maintenance checks and found that the intervals

varied from 1 to 27 years.

In Air Transport Association of America (ATA) memorandum number 96-

AE-014, dated March 11, 1996, the Airworthiness Concern Coordination

Task Force recommended that ``a `C' check compliance period (18 months)

or `D' check period (5 years) be adopted for all rules unless it can be

shown that a shorter time interval is required for safety reasons.'' A

copy of this memorandum has been placed in the docket.

Individual operator maintenance or inspection check intervals have

been adjusted over the years based on service experience and the

operational environment of the aircraft. The adjustment, for the most

part, has been toward increasing the time between subsequent check

intervals. Consequently, maintenance check intervals vary among

operators. To comply with the AASA, the 5-year repetitive interval

after the initial inspection, not withstanding the escalations, best

helps accomplish the safety goal of the AASA.

The FAA has determined that the best approach is to specify a fixed

repeat interval when the Administrator will carry out records reviews

and inspections of the affected airplanes. The FAA has chosen the 5-

year repeat interval to meet its obligations, as established in 49

U.S.C. 44717.

To reduce the burden on the operator, the record reviews and

inspections could take place at any time before the deadlines specified

in the proposal. This allows the inspections to coincide with an

airplane's normally scheduled maintenance visit when structural

components are accessible for inspection. However, if an operator's

maintenance interval exceeds 5 years, the operator will be obligated

sooner than the end of the interval to make the airplane available to

the Administrator or the Administrator's designee for the records

review and inspection required by this proposal. For many smaller

airplanes, the maintenance visit intervals are less than 5 years. In

those cases, the repetitive intervals of the aging airplane records

reviews and inspections would not exceed 5 years.

Conducting the inspections during normally scheduled maintenance

visits will allow maximum use of the FAA's resources while minimizing

the disruption to the operator. It also ensures that a significant

portion of the airplane is accessible to the Administrator or the

Administrator's designee and allows, to the extent

[[Page 16301]]

possible, a visible determination of compliance with aging aircraft

requirements. Although it is the FAA's intent to carry out records

reviews and inspections to the extent that the aircraft structure is

accessible during the maintenance visit, the FAA may require additional

access to determine that the maintenance of the airplane's age-

sensitive parts and components has been adequate and timely.

The proposed rule specifies that airplanes already at their 25th

year in service must be inspected within 3 years after the effective

date of the rule. This earlier compliance time for the older airplanes

will ensure that the oldest airplanes are inspected first and will

distribute the workload for the initial inspections. The FAA estimates

that 1,550 airplanes affected by this proposed rule would exceed 24

years in service by 1998. The estimated number of airplanes that will

be 15 years old by 1998 is 2,850. Therefore, the proposed rule provides

for approximately 1,500 airplanes to be inspected within the first 3

years following the effective date of the rule, followed by an

approximately equal amount to be inspected in the subsequent 2 years.

The proposed rule also would require the operator to notify the FAA

60 days before the aircraft is available for the aging airplane records

review and inspection. This would ensure that the Administrator or the

Administrator's designee would be able to make the plans necessary to

accomplish the aging airplane records review and inspection.

Records Review

For the Administrator to fulfill his or her obligation under 49

U.S.C. 44717, this proposal would require that certain records be made

available by the operator. Operators are already required by existing

regulations to maintain these records and reports. Although the

proposal would require status lists and reports of specific maintenance

actions, if needed, the FAA has the authority under exiting regulations

to request all supporting documentation for the lists.

This proposal would establish a new requirement for ``total years

in service.'' The FAA has determined that this new requirement is

essential for the Administrator and the operator to determine the

compliance time for the initial and repetitive inspections. To meet

this requirement, the operator would retain records validating when the

initial certificate of airworthiness was issued for each airplane.

In addition, the FAA is aware that an airframe's flight cycles are

not currently being collected by operators of small airplanes under

part 135. This proposal would require that the operator make certain

records and reports available to the FAA during the proposed aging

airplane records review inspection.

Damage-Tolerance-Based Inspections and Procedures

A damage-tolerance-based inspection and procedure refers to ``an

inspection program that specifies procedures, thresholds, and repeat

intervals that have been developed using damage-tolerance principles.''

Damage-tolerance-based inspections and procedures are developed by a

manufacturer or operator based on an engineering evaluation of likely

sites where damage could occur, considering expected stress levels,

material characteristics, and projected crack growth rates. Damage-

tolerance-based inspections and procedures identify inspection sites,

specify inspection techniques; define thresholds for the initial

inspection; and prescribe repeat inspection intervals. Test data and

service experience are used to support the analysis.

The most important information used to develop a damage-tolerance-

based inspection and procedure is derived analytically or by test, and

the inspections are intended to anticipate locations where fatigue

cracking might occur. Therefore, it is inappropriate to change damage-

tolerance-based inspections and procedures solely on service experience

without a significant engineering evaluation to confirm that there are

no areas subject to fatigue cracking other than those revealed by the

service experience. The engineering evaluation should include

considering the detailed design data of the airplane, which is under

the control of the manufacturer. For this reason, all damage-tolerance-

based inspections and procedures should be developed under the

technical direction of the type certificate holder for that airplane,

with support from the operators when appropriate. However, the FAA

would consider damage-tolerance-based inspections and procedures

submitted by any applicant for approval if they are based on tests and

service-supported damage-tolerance evaluations for that airplane model.

The damage-tolerance-based inspections and procedures specified in

this proposal can be developed using one of the following methods:

(1) Damage-tolerance-based inspections and procedures that comply

with Sec. 25.571, Amendment 25-45 (43 FR 46238), or that comply with a

subsequent amendment thereto;

(2) Damage-tolerance-based inspections and procedures that comply

with the damage-tolerance provisions for metallic structure listed in

14 CFR 23.573, Amendment 23-45 (58 FR 42163), or that comply with a

subsequent amendment thereto;

(3) AC 91-56 ``Supplemental Structural Inspection Program for Large

Transport Category Airplanes'' dated May 6, 1981;

(4) Draft AC 91-MA ``Continued Airworthiness of Older Small

Transport and Commuter Airplanes; Establishment of Supplemental

Inspection Programs.'' A notice of availability for this AC is

published concurrently with this proposal; or

(5) Any other method that the Administrator finds complies with the

principles of damage tolerance.

Although this proposed rule specifies dates by which damage-

tolerance-based inspections and procedures would be required, the

thresholds for these inspections may occur much later. While the

damage-tolerance-based inspections and procedures would need to be

developed within the regulatory timeframe proposed, the times when the

inspections would be completed would depend on the damage-tolerance

assessment.

For newly certificated airplanes, damage-tolerance-based

inspections necessary to prevent catastrophic failure must be included

in the Airworthiness Limitations Section of the Instructions for

Continued Airworthiness required by 23.1529 or 25.1529.

Damage-tolerance-based inspections and procedures for airplanes

certificated before the amendments that require damage tolerance as

part of airplane type design may be approved through an amended or

supplemental type certificate. Such a certificate would identify the

damage-tolerance-based inspections and procedures as an airworthiness

limitation on the airplane.

Damage-tolerance-based inspections and procedures for certain older

airplanes also may be approved by a Letter of Approval issued by the

FAA Aircraft Certification Office cognizant of the type certificate.

The Letter of Approval would place an operational requirement for the

operator's affected airplanes.

For some airplanes, the FAA has approved major structural

modifications under a supplemental type certificate (STC). The original

airplane manufacturer may not have sufficient technical data pertinent

to these modifications to assist the airplane operators in conducting a

damage-tolerance assessment of the modification. In these situations,

the FAA expects the operator to work with the STC holder and the

original airplane

[[Page 16302]]

manufacturer to develop damage-tolerance-based inspections and

procedures for that modification. In some instances, the operator may

not be able to work with the STC holder or manufacturer. These

operators may elect to conduct their own damage-tolerance assessments.

If an operator elects to develop damage-tolerance-based inspections and

procedures in this fashion, competent engineering personnel, as well as

inspection findings from the current maintenance or inspection program,

should be used in conjunction with the airplane's design data base and

model fleet experience. These data should be developed by the original

manufacturer, and the STC holder should provide the basis for the

damage-tolerance-based inspections and procedures; however, the

operator also can develop its own data. FAA-approved major structural

repairs should be analyzed in the same manner as modifications

accomplished under an STC. Such procedures ensure that damage-

tolerance-based inspections and procedures address each airplane

affected by this proposal, including any modifications or repairs made

to the basic airframe.

The FAA is aware that for some currently operating airplanes it may

be difficult to develop damage-tolerance-based inspections and

procedures. For example, the manufacturer may have gone out of

business; technical data may not be adequate; the technical knowledge

base may no longer be readily available; or the development of a

damage-tolerance-based inspections and procedures may not be

economically viable. If any of these conditions exist and appropriate

damage-tolerance-based inspections and procedures cannot be developed

those airplanes would not be eligible for operation under part 121,

129, or 135 after the dates specified in the proposal.

Non-damage-tolerance-based SIPs based on AC 91-60 have been

mandated by ADs on the following airplanes: Douglas DC-3 and DC-6;

Convair 240, 340, 440, 580, and 600 series; Lockheed Electra; and the

Fokker F-27. Although inspections and procedures based on AC No. 91-60

address known service difficulties, they do not anticipate the

possibility of future fatigue cracks that could be predicted through

the use of damage-tolerance principles. Some inspection programs

developed in accordance with AC No. 91-60 do not qualify as damage-

tolerance-based inspections and procedures because they are either

based solely on service experience or they may combine partial damage-

tolerance assessments with service experience. For these reasons, the

proposed rule would not allow continued use of inspection programs

based on AC No. 91-60 alone. Instead, it proposes to require damage-

tolerance-based inspections and procedures to supplement or replace

existing inspection programs based on AC No. 91-60 no later than

December 20, 2010.

Designated Airworthiness Representatives (DAR)

Section 44717 of 49 U.S.C. allows the Administrator to delegate the

aging aircraft records reviews and inspections to properly qualified

private persons as provided under 49 U.S.C. 44701(a)(2)(B) and (C). The

FAA normally delegates similar authority to individuals under 49 U.S.C.

44702(d). Those delegations are contained in part 183. Because of the

large number of airplanes (over 3,000) that would have to be inspected

in a short period of time (5 years) and an anticipated growth of the

aging fleet, the FAA proposes to permit such records reviews and

inspections to be accomplished by a DAR authorized under part 183.

This proposal would revise current Sec. 183.33 to permit DARs to

conduct the reviews and inspections necessary to determine the

continued effectiveness of airworthiness certificates, including the

proposed reviews and inspections. The FAA would issue guidelines to its

aviation safety inspectors and DARs on how to monitor and conduct

records reviews and inspections in compliance with this proposed rule.

Proposed Appendixes

The proposed appendixes list the FAA-established design-life goals

of several airplane types that are commonly used in scheduled service

to assist in implementing this proposal.

For airplane models listed in the proposed appendix to part 121 and

for airplane models initially certificated to carry 10 or more

passengers located in the proposed appendix to part 129 and the

proposed appendix to part 135, the proposal could effectively delay the

implementation date of damage-tolerance-based inspections and

procedures for these aircraft from 4 years after the effective date of

the rule to the time the aircraft reaches its design-life goal.

However, for airplane models initially certificated to carry nine

or fewer passengers listed in the proposed appendixes to part 129 and

part 135, the proposal requires damage-tolerance-based inspections and

procedures sooner than December 20, 2010.

The airplane models with 10 or more passenger seats listed in the

proposed appendixes have been certificated with limits on either the

structure or the maintenance program, or they have had subsequent

structural analysis and testing. These limits are considered adequate

to ensure the safety of these airplanes until they reach the listed

design-life goal.

Early small airplane regulations did not consider fatigue until

1956, and then only on pressurized fuselages. With the exception of the

Fairchild Model SA227-TT, the passenger airplanes with nine or fewer

seats included in the proposed appendixes to part 129 and part 135 were

initially certificated in the United States without any consideration

being given to wing or empennage fatigue. However, the airworthiness

authorities of the United Kingdom and Australia required fatigue

evaluation on these airplanes before allowing operation in their

countries. The airplane models listed in the proposed appendixes have

been used consistently in scheduled commuter service in the United

States for the past several years, and many of the highest-time

airplanes have accumulated a number of flight hours approaching or

exceeding the limits set by the airworthiness authorities of these

other countries.

Most airplanes with a capacity for nine or fewer passengers were

not listed in the appendixes because these airplanes are not commonly

used in U.S. commuter operations and tend to have lower fleet times.

Most were designed with sufficiently low stresses to allow them to

operate safely without the need for damage-tolerance-based inspections

and procedures before December 20, 2010.

However, if at a later date the FAA learns of specific airplanes

with nine or fewer passenger seats commonly being used in commuter

service with flight hours approaching or exceeding the limits set by

the airworthiness authorities of other countries, the FAA will consider

future rulemaking to add those models to the proposed appendixes.

A description of the airplanes in the proposed appendixes and their

associated design-life goals are listed below. The FAA has reviewed the

assessments that resulted in the life limit requirements described

below, and has determined that those requirements appropriately, if not

conservatively, reflect the times in the aircraft's service lives when

significant maintenance must be performed on the critical structures to

maintain the level of safety required for air transportation.

[[Page 16303]]

Beech 99 (All Models)

The Beech 99 is an unpressurized, 17-seat airplane configured for

15 passenger seats and 2 pilot seats. The Beech 99 initially was

certificated in 1968 under part 23, Amendment No. 3, and is listed on

type certificate data sheet (TCDS) A14CE. Special conditions were

imposed on the Beech 99 to require fatigue validation testing of the

wing and carry-through structure. In 1990, Beech Aircraft Company

issued Mandatory Service Bulletin No. 2297 to require replacement of

the entire outboard wing and the entire wing center section after

46,000 hours. This retirement time is based on full-scale fatigue

testing.

Beech 1900 (All Models)

The Beech 1900, 1900C, and 1900D are pressurized, 21-seat airplanes

configured for 19 passenger seats and 2 pilot seats. The 1900 and 1900C

were initially certificated under Special Federal Aviation Regulation

(SFAR) No. 41 in 1983, and the Beech 1900D was initially certificated

in the commuter category in 1991. All models are listed on TCDS A24CE.

All three models have certified life limits of 45,000 hours for the

empennage listed in the Airworthiness Limitations sections of their

maintenance manuals.

Beech 300, 300LW, B300, and B300C

The Beech 300, 300LW, B300, and B300C are 15-seat airplanes

configured for 13 passenger seats and 2 pilot seats. The Beech 300 and

300LW were initially certificated under SFAR No. 41 in 1988, and the

Beech B300 and B300C were initially certificated in the commuter

category in 1989. All models are listed on TCDS A24CE. All four models

have certified 30,000-hour life limits for the empennage listed in the

Airworthiness Limitations sections of their maintenance manuals.

BAe Jetstream Models 3101 and 3201

The BAe Jetstream 3101 and 3201 are pressurized, 21-seat airplanes

configured for 19 passenger seats and 2 pilot seats. The Jetstream 3101

was initially certificated under SFAR No. 41 in 1982 and is listed on

TCDS A21EU. The Jetstream 3201 was initially certificated in the

commuter category in 1988 and is listed on TCDS A56EU. Both airplanes

have certified life limits of 30,000 landings for the wing and

empennage listed in the Airworthiness Limitations sections of their

maintenance manuals. For flights of 1 hour in length, this equates to a

30,000-hour limit.

Cessna 402

The Cessna 402 is a small, unpressurized, 10-seat airplane

configured for 8 passenger seats and 2 pilot seats. The Cessna 402 was

initially certificated in 1956, the Cessna 402A and 402B in 1969, and

the Cessna 402C in 1978. They are listed on TCDS A7CE and were

certificated in the United States without fatigue requirements. The

402, 402A, and 402B are subjected to AD No. 79-10-15, which mandates a

400-hour repetitive inspection for fatigue cracks on critical

components of the wing structure. The proposed appendixes list a

design-life goal of 12,000 hours for these aircraft, based on recent

Cessna Aircraft Company calculations. The appendix lists a design-life

goal of 7,700 hours for the Cessna 402C, based on fatigue limits set on

the wing structure by the Airworthiness Authorities of Australia and

the United Kingdom.

De Havilland DHC-6 (all models)

The de Havilland DHC-6 is an unpressurized, 24-seat airplane

configured for 22 passenger seats and 2 pilot seats. The DHC-6 was

initially certificated in 1966 under Civil Air Regulation (CAR) 3,

Amendment No. 8, and in 1969 under SFAR No. 23, and is listed on TCDS

A9EA. Transport Canada, designated as the airworthiness authority of

the country of design by ICAO for the continued airworthiness of the

DHC-6, issued an AD that is mandatory in Canada and imposes service

life limits on the airplanes listed in the de Havilland Structural

Components Service Life Limits Manual, PSM 1-6-11, Revision 4, dated

May 31, 1996. This Canadian AD, issued in September 1996, mandates the

retirement of the airplane at 66,000 hours.

Dornier DO-228 (all models)

The Dornier DO-228 is an unpressurized, 21-seat airplane configured

for 19 passenger seats and 2 pilot seats. The DO-228-100 and DO-228-200

were initially certificated in 1984, the DO-228-101 and DO-228-201 in

1985, and the DO-228-202 in 1986 under part 23, Amendment No. 23, and

SFAR No. 41C. The DO-228-212 was certificated in the commuter category

in 1990. All are listed on TCDS A16EU. The Airplane Maintenance Manual

for the DO-228-100/-101 and DO-228-200/-201/-202/-212 includes

Airworthiness Limitation section 05-05-00, which specifies mandatory

airplane replacement times. The DO-228-100 and DO-228-200 have a

fatigue life of 42,800 hours; the DO-228-101 and DO-228-201 have a

fatigue life of 32,800 hours; and the DO-228-202 has a fatigue life of

29,600 hours. The fatigue life for the DO-228-212 is 26,400 hours for

all serial numbers except 155, and serial numbers 191 and higher; and

42,800 hours for serial number 155 and serial numbers 191 and higher.

Embraer EMB-110

The Embraer EMB-110 is a pressurized, 21-seat airplane configured

for 19 passenger seats and 2 pilot seats. The EMB-110 was initially

certificated under SFAR No. 41A in 1978 and is listed on TCDS A21SO.

The EMB-110 was initially certificated with a 30,000-hour life limit on

the wing and carry-through structure. This limit is listed in Note 3 of

TCDS A21SO.

Fairchild Metro SA227

The Fairchild Metro SA227 series includes the SA227-AT, -TT, -AC, -

BC, -PC, -CC, and -DD airplanes. The SA227-AT is a 16-seat airplane

configured for 14 passenger seats and 2 pilot seats. It was initially

certificated under SFAR No. 41C in 1981. The SA227-TT is an 11-seat

airplane configured for 9 passenger seats and 2 pilot seats. It was

initially certificated under SFAR No. 41B in 1981. Both models are

listed on TCDS A5SW and have 35,000-hour certified life limits on their

empennages.

The SA227-AC, -BC, and -PC are pressurized, 22-seat airplanes

configured for 20 passenger seats and 2 pilot seats. They were

initially certificated under SFAR No. 41C in 1981, 1989, and 1985,

respectively. All three models are listed on TCDS A8SW and have a

35,000-hour certified empennage life.

The SA227-CC and -DC are pressurized, 21-seat airplanes configured

for 19 passenger seats and 2 pilot seats. They were initially

certificated in the commuter category of part 23 in 1990. Both models

are listed on TCDS A18SW and have 35,000-hour certified empennage life

limits.

Fairchild Metro SA226-TC

The SA226-TC is a pressurized, 22-seat airplane configured for 20

passenger seats and 2 pilot seats. It was initially certificated under

part 23, Amendment No. 6, in 1970, and later certificated under SFAR

No. 41C in 1982. It is listed on TCDS A8SW and has a 35,000-hour

certified empennage life limit.

[[Page 16304]]

Pilatus Britten-Norman BN-2A MK III (all models)

The Pilatus Britten-Norman BN-2A MK III Trislander is an

unpressurized, 18-seat airplane configured for 16 passenger seats and 2

pilot seats. The BN-2A MK III was initially certificated in 1971 under

part 23, Amendment No. 8, and is listed on TCDS A29EU. The wing is

limited to 23,900 hours at initial certification, assuming one landing

per flight hour. For shorter flights, the wing is limited to 20,480

hours. This notice proposes the more conservative number.

Piper Navajo and PA-31 Series

The Piper Navajo and PA-31 series airplanes are 7- to 11-seat

airplanes with seating configurations of 5 to 9 passenger seats and 2

pilot seats. Those airplanes listed in the appendixes are capable of

carrying six or more passenger seats and have been used in commuter

service in significant numbers for several years. There are pressurized

and unpressurized versions and models powered by piston or by

turbopropeller engines. The unpressurized versions are listed on TCDS

A20SO, and the pressurized versions are listed on TCDS A8EA. The

unpressurized versions were certificated in the United States under

older regulations that did not require fatigue substantiation, and the

pressurized versions have no fatigue certification of the wing

structure and no fatigue limits on the pressurized cabin.

The Civil Airworthiness Authorities (CAA) of Australia and the

United Kingdom required fatigue substantiation of these airplanes as a

condition for their initial certification. The design-life goals listed

in the appendixes represent limits certified by the Australian CAA. The

limits for unpressurized models are based on the fatigue limits of the

wing spar lower cap, and the limits for the pressurized models are

based on the pressurized cabin.

Short Brothers SD3-30

The Short Brothers SD3-30 is a 32-seat airplane configured for 30

passenger seats and 2 pilot seats. The SD3-30 was certificated in the

United States in 1976 under part 25, Amendment No. 30. The manufacturer

has limited the maintenance program to 57,600-flight hours contingent

on the successful completion of a mid-life inspection at 28,800 hours,

as defined in the airplane maintenance manual.

Short Brothers SD3-60

The Short Brothers SD3-60 is a 41-seat airplane configured for 39

passenger seats and 2 pilot seats. The SD3-30 was certificated in the

United States in 1982 under a United Kingdom certification basis that

is equivalent to part 25, Amendment No. 34. The manufacturer has

limited the maintenance program to 28,800 hours, as defined in the

airplane maintenance manual.

Short Brothers SD3-Sherpa

The Short Brothers SD3-Sherpa is a 32-seat airplane configured for

30 passenger seats and 2 pilot seats. The SD3-30 was certificated in

the United States in 1990 under a United Kingdom certification basis

and to the additional validation requirements of part 25, Amendment No.

35. The manufacturer has limited the maintenance program to 40,000

hours, as defined in the airplane maintenance manual.

Related Activity

Concurrent with this proposal, the FAA is issuing two Notices of

Availability of ACs. The first, AC No. 91-MA, ``Continued Airworthiness

of Older Small Transport and Commuter Airplanes; Establishment of

Supplemental Inspection Programs,'' provides an acceptable means, but

not the only means, to comply with the proposed damage-tolerance-based

inspections and procedures. The second, AC No. 120-XX, ``Aging Airplane

Records Reviews and Inspections,'' provides guidance regarding how an

operator complies with this proposal.

There are other initiatives being considered by the FAA to address

Aging Aircraft issues. The FAA has received a recommendation from the

Aviation Rulemaking Advisory Committee (ARAC) on rulemaking in the area

of repair assessment of pressurized fuselages. The proposal would

require a repair assessment for the pressurized fuselages of Airbus

A300; Boeing 707/720, 727, 737, and 747; Douglas DC-8, DC-9/MD-80, and

DC-10; British Aerospace BAC 1-11; Fokker F-28; and Lockheed L10-11

airplanes. The recommendation currently is being reviewed within the

FAA, and publication of an NPRM is anticipated in the near future.

In addition, the FAA has found that some operators do not have a

programmatic approach in place to appropriately address airplane

corrosion. A rulemaking effort is being considered that would require

development and implementation of a corrosion prevention and control

program for all airplanes used in air transportation. The FAA

anticipates publication of rulemaking on this subject in 1998.

On December 20, 1995, the FAA issued the final rule, ``Commuter

Operations and General Certification and Operations Requirements'' (60

FR 65832), also known as the ``Commuter Rule,'' to address commuter air

operations in the United States. That rulemaking requires that all

airplanes used in scheduled passenger service capable of carrying 10 or

more passengers meet specific performance requirements by December 20,

2010. For some older airplanes, significant modifications would be

necessary to meet those new requirements. That rulemaking provided an

extended compliance date to give operators time to decide whether to

retrofit those airplanes or phase them out of scheduled service.

Because development of damage-tolerance-based inspections and

procedures may be difficult for some airplanes currently operating in

scheduled service, the FAA is proposing December 20, 2010, as a

compliance date for this rulemaking.

Section-by-Section Analysis

Section 119.3

This section would be revised to include the definition of ``years

in service.''

Section 121.368

Proposed paragraph (a) specifies that the Administrator will

conduct the records reviews and inspections as necessary to decide

whether an airplane is in safe condition and maintained properly for

operation in air transportation.

Proposed paragraph (b) would prohibit a certificate holder from

operating an airplane after a date specified in the section unless the

Administrator has completed the aging aircraft records review and

inspection.

Proposed paragraph (b) also would set forth the times by which a

certificate holder must ensure its airplanes are inspected. Aging

airplanes are divided into three categories for these inspections to

ensure that the oldest aircraft are inspected first. For those

airplanes that will have exceeded 24 years in service, the first

records review and inspection would be required no later than 3 years

after the effective date of the proposed rule. For those airplanes

exceeding 14 but not 24 years in service at the time the proposed rule

becomes effective, the first records review and inspection would be

required no later than 5 years after the effective date of the proposed

rule. Finally, airplanes that will exceed 14 years in service

subsequent to the proposed rule's effective date would be required to

[[Page 16305]]

undergo the first records review and inspection no later than 5 years

after their 14th year in service. All aging airplane records reviews

and inspections specified in this section would need to be repeated at

intervals not to exceed 5 years.

Proposed paragraph (c) would permit the Administrator to approve

90-day extensions on the thresholds and repeat intervals of aging

aircraft records reviews and inspections to accommodate unforeseen

scheduling conflicts.

Proposed paragraph (d) would require a certificate holder to make

an affected airplane and certain associated records available for

review and inspection.

Proposed paragraph (e) would require a certificate holder to notify

the Administrator at least 60 days before the airplane and its

associated records would be made available for review and inspection.

Section 121.370a

Proposed paragraph (a) would require certificate holders to ensure

that, subject to certain limited exceptions, the maintenance programs

for airplanes operating under part 121 include damage-tolerance-based

inspections and procedures within 4 years after the effective date of

the rule.

Proposed paragraph (b) would permit operators of airplanes listed

in appendix M to part 121 to operate these airplanes without non-

damage-tolerance-based inspections and procedures in their maintenance

programs until reaching a design-life goal specified in the appendix,

or 4 years after the effective date of the rule, whichever occurs

later. However, no aircraft may operate without damage-tolerance-based

inspections and procedures after December 20, 2010.

Proposed paragraph (c) would permit operators of airplanes that

have non-damage-tolerance-based inspections and procedures already

mandated by ADs to continue to operate those airplanes until December

20, 2010. After that date, the operator must have damage-tolerance-

based inspections and procedures as part of their maintenance programs

to be eligible to operate those airplanes under part 121.

Part 121, Appendix N

This appendix lists the airplanes and the design-life goals that

are referenced in proposed Sec. 121.370a.

Section 129.1

Paragraph (a) would update the reference to section 402 of the

repealed and recodified FAA Act of 1958.

Paragraph (b) would clarify that proposed Secs. 129.16 and 129.20

also apply to operations of U.S.-registered aircraft operated solely

outside the United States.

Section 129.16

This proposed section is similar to proposed Sec. 121.370a.

Proposed paragraph (a) would require foreign air carriers or

foreign persons who operate U.S.-registered multiengine airplanes that

were initially type certificated with 10 or more passenger seats to

include damage-tolerance-based inspections and procedures in their

maintenance programs within 4 years of the effective date of the

proposed rule.

Proposed paragraph (b) would require foreign air carriers or

foreign persons who operate U.S.-registered multiengine airplanes that

were initially type certificated with nine or fewer passenger seats to

include damage-tolerance-based inspections and procedures in their

maintenance programs before December 20, 2010.

Proposed paragraph (c) would permit foreign air carriers or foreign

persons to operate U.S.-registered airplanes of the type listed in

appendix B to part 129 without damage-tolerance-based inspections and

procedures in their maintenance programs until reaching a design-life

goal specified in the appendix, or 4 years after the effective date of

the proposed rule, whichever occurs later. However, no airplane may be

operated without damage-tolerance-based inspections and procedures

after December 20, 2010.

Proposed paragraph (d) would permit foreign air carriers or foreign

persons to operate U.S.-registered airplanes that have non-damage-

tolerance-based inspections and procedures already mandated by ADs to

continue to operate those airplanes until December 20, 2010. After that

date, the operator must have damage-tolerance-based inspections and

procedures as part of their maintenance programs to be eligible to

operate those airplanes under part 129.

Section 129.33

This proposed section is similar to proposed Sec. 121.368.

Proposed paragraph (a) specifies that the Administrator will

conduct the records reviews and inspections as necessary to decide

whether an airplane is in safe condition and maintained properly for

operation in air transportation.

Proposed paragraph (b) would prohibit a foreign air carrier or

foreign person from operating a U.S.-registered airplane after a date

specified in the section unless the Administrator has completed the

aging aircraft records review and inspection.

Proposed paragraph (b) also would set forth the times by which a

foreign air carrier or foreign person must ensure its U.S.-registered

multiengine airplanes are inspected. Aging airplanes are divided into

three categories for these inspections to ensure that the oldest

airplanes are inspected first. For those airplanes that will have

exceeded 24 years in service, the first records review and inspection

would be required no later than 3 years after the effective date of the

proposed rule. For those airplanes exceeding 14 but not 24 years in

service at the time the proposed rule becomes effective, the first

records review and inspection would be required no later than 5 years

after the effective date of the proposed rule. Finally, airplanes that

will exceed 14 years in service subsequent to the proposed rule's

effective date would be required to undergo the first records review

and inspection no later than 5 years after the 14th year in service.

All aging airplanes records reviews and inspections specified in this

section would need to be repeated at intervals not to exceed 5 years.

Proposed paragraph (c) would permit the Administrator to approve

90-day extensions on the thresholds and repeat intervals of aging

airplane records review and inspection to accommodate unforeseen

scheduling conflicts.

Proposed paragraph (d) would require a foreign air carrier or

foreign person to make an affected airplane and certain associated

records available for review and inspection.

Proposed paragraph (e) would require a foreign air carrier or

foreign person to notify the Administrator at least 60 days before the

airplane and its associated records would be made available for review

and inspection.

Part 129, Appendix B

This appendix would list the airplanes and the design-life goals

that are referenced in proposed Sec. 129.16.

Section 135.168

This proposed section is similar to proposed Secs. 121.370a and

129.16.

Proposed paragraph (a) would require operators of multiengine

airplanes operating in scheduled service that were initially type

certificated with 10 or more passenger seats to include damage-

tolerance-based inspections and procedures in their inspection programs

within 4 years of the effective date of the proposed rule.

Proposed paragraph (b) would require operators of multiengine

airplanes in

[[Page 16306]]

scheduled service that were initially type certificated with nine or

fewer passenger seats to include damage-tolerance-based inspections and

procedures in their inspection programs before December 20, 2010.

Proposed paragraph (c) would permit operators of airplanes listed

in appendix F to part 135 to operate these airplanes in scheduled

service without damage-tolerance-based inspections and procedures in

their inspection programs until reaching a design-life goal specified

in the appendix, or 4 years after the effective date of the proposed

rule, whichever occurs later. However, no airplane may be operated

without damage-tolerance-based inspections and procedures after

December 20, 2010.

Proposed paragraph (d) would permit operators of airplanes that

have non-damage-tolerance-based inspections and procedures already

mandated by ADs to continue to operate those airplanes until December

20, 2010. After that date, the operator must have damage-tolerance-

based inspections and procedures as part of their inspection programs

to be eligible to operate those airplanes under part 135.

Section 135.422

The proposed section is similar to proposed Secs. 121.368 and

129.20.

Proposed paragraph (a) specifies that the Administrator will

conduct the records reviews and inspections as necessary to decide

whether an airplane is in safe condition and maintained properly for

operation in air transportation.

Proposed paragraph (b) would prohibit a certificate holder from

operating a multiengine airplane in scheduled operations after a date

specified in the section unless the Administrator has completed the

aging airplane records reviews and inspections.