Revisions to Digital Flight Data Recorder Regulations for Boeing 737 Airplanes and for Part 125 Operations

SUMMARY: The FAA proposes to amend the digital flight data recorder

(DFDR) regulations for transport category airplanes to add a

requirement for all Boeing 737 (B-737) series airplanes to record

additional flight data parameters. This proposal is based on safety

recommendations issued by the National Transportation Safety Board

(NTSB) following the investigations of two accidents and other

incidents involving B-737 aircraft. The additional parameters that

would be recorded would provide the only currently available means of

gathering information that the FAA and the NTSB anticipate will help

assess the reasons for continuing incidents that appear related to

rudder anomalies on B-737 airplanes. In addition, the FAA is proposing

a change to the flight data recorder requirements of part 125 that

would affect all aircraft operated under that part or under deviation

from that part.

DATES: Comments must be received on or before December 20, 1999.

ADDRESSES: Comments on this document should be mailed or delivered, in

duplicate, to: U.S. Department of Transportation Dockets, Docket No.

[FAA-1999-6482], 400 Seventh Street SW., Room Plaza 401, Washington, DC

20590. Comments also may be sent electronically to the following

Internet address: [email protected] Comments may be filed and

examined in Room Plaza 401 between 10 a.m. and 5 p.m. weekdays, except

Federal holidays.

FOR FURTHER INFORMATION CONTACT: George Kaseote, Aircraft Certification

Service, AIR-130, Federal Aviation Administration, 800 Independence

Avenue SW., Washington, DC 20591; telephone (202) 267-8541; facsimile

(202) 493-5173.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the

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

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

federalism, or economic impact that might result from adopting the

proposals in this document also are invited. Substantive comments

should be accompanied by cost estimates. Comments must identify the

regulatory docket or notice number and be submitted in duplicate to the

DOT Rules Docket address specified above.

All comments received, as well as a report summarizing each

substantive public contact with FAA personnel concerning this proposed

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. Comments filed late will be considered as far as possible

without incurring expense or delay. The proposals in this document may

be changed in light of the comments received.

Commenters wishing the FAA to acknowledge receipt of their comments

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

stamped postcard with those comments on which the following statement

is made: ``Comments to Docket No. FAA-1999-6482.'' The postcard will be

date stamped and mailed to the commenter.

Availability of NPRMs

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) and the Government Printing Office (GPO)'s electronic

bulletin board service (telephone: (202) 512-1661).

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

avr/arm/nprm/nprm.htm or the GPO's web page at http://

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

documents.

Any person may obtain a copy of this document 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

rulemaking documents 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

Statement of the Problem

Two aviation accidents in the United States involving Boeing 737

(B-737) model airplanes appear to have been caused by a rudder hardover

with resultant roll and sudden descent: United Airlines (United) flight

585, near Colorado Springs, Colorado, on March 3, 1991, and USAir

flight 427, near Aliquippa, Pennsylvania, on September 8, 1994. The

NTSB has determined that the rudder on B-737 airplanes may experience

sudden uncommanded movement or movement opposite the pilot's input,

which may cause the airplane to roll suddenly. Incidents of suspected

uncommanded rudder movement continue to be reported, including five

incidents in 1999 involving U.S.-registered airplanes.1

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

\1\ On February 23, 1999, a USAirways Metrojet B-737-200

experience a roll to the left with no change in heading. This

incident is further described later in this NPRM. On February 23,

1999, A USAirways B-737-200 experienced an uncommanded rudder

movement shortly after departure. On March 12, 1999, a Delta Air

Lines B-737-247 experienced a 2-second uncommanded yaw to the right

during cruise flight. On April 13, 1999, a United B-737-300

experienced an uncommanded 20 to 30 degree roll to the left during

level cruise flight described as a ``sharp quick uncommanded kick to

the left.'' On April 10, 1999, a United B-737-300 aborted its

takeoff roll because of an uncommanded yaw event as the airplane

passed through 120 to 130 knots.

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

The B-737 airplanes involved in the United and USAir accidents and

in the recent rudder incidents were equipped with the required flight

data recorders (FDRs), but none of the recorders provided information

about the airplanes' movement about their three axes or the positions

of the flight control surfaces immediately preceding the accidents or

incidents. To date, corrective measures taken to resolve the suspected

problem have been limited by the lack of data being recorded. More data

is needed to help identify events occurring during suspected

uncommanded or hardover rudder events.

The FAA has issued 17 airworthiness directives (ADs) for the B-737

airplane as a result of the investigation into the USAir accident,

including one that addresses an upgraded rudder power control unit

(PCU) designed to remedy one element of the rudder upset problem, a

rudder reversal. Suspected rudder upsets continue to occur, however,

and some of the B-737 airplanes that recently experienced

[[Page 63141]]

suspected uncommanded rudder movements (not reversals) had been

modified with the upgraded rudder PCU, suggesting that other events are

still occurring in the rudder system.

The FAA agrees with the NTSB's conclusion that the collection of

additional rudder system and flight control data are necessary to more

effectively assess the cause of the continued uncommanded rudder

movements and to possibly design a solution. The NTSB stated in its

safety recommendations that all B-737 airplanes should record pitch

trim, trailing and leading edge flaps, thrust reverser position, yaw

damper command, yaw damper status (on/off), standby rudder status (on/

off), and control wheel, control column, and rudder pedal forces.

Summary of B-737 Accidents

United Flight 585

On March 3, 1991, United flight 585, a B-737-291, was on a

scheduled passenger flight from Denver to Colorado Springs, Colorado.

As the airplane was completing its turn to final approach, it rolled

rapidly to the right and pitched down, reaching a nearly vertical

attitude before it struck the ground. The airplane was destroyed and

none of the 5 crewmembers or 20 passengers survived. The FDR recorded

five flight data parameters (altitude, airspeed, heading, vertical

acceleration, and microphone keying) in accordance with the applicable

regulations for an airplane its age. The FDR was not required to record

other parameters that the NTSB later perceived as critical to its

accident investigation, including airplane pitch and roll attitude,

engine thrust, lateral and longitudinal acceleration, control wheel

position, rudder pedal position, and the position of the control

surfaces (rudder, aileron, and spoiler). The NTSB was unable to make a

determination of the probable cause of the accident.

USAir Flight 427

On September 8, 1994, USAir flight 427, a B-737-3B7, was on a

scheduled passenger flight from Chicago, Illinois, to Pittsburgh,

Pennsylvania, when, during the approach to Pittsburgh, the airplane

suddenly rolled to the left and pitched down until it reached a nearly

vertical attitude and struck the ground near Aliquippa, Pennsylvania.

The airplane was destroyed and none of the 5 crewmembers or 127

passengers survived. The FDR was equipped to record the following 13

parameters: altitude, airspeed, heading, pitch attitude, roll attitude,

vertical acceleration, longitudinal acceleration, microphone keying,

low pressure compressor speed, high pressure compressor speed, exhaust

gas temperature, fuel flow, and control column position.

NTSB Investigation of USAir Flight 427

Early in the investigation of the USAir accident, the NTSB noticed

that the airplane experienced a high rate of change in its heading, an

indication that the initial upset of the airplane may have been caused

by uncommanded rudder movement. This situation had been considered in

the 1991 United flight 585 accident investigation, and the NTSB

reviewed the information it had collected from the United accident as

the USAir investigation continued. Another rudder upset incident

occurred on an Eastwind Airlines2 B-737 while the USAir

investigation continued, and a concurrent investigation was opened. The

Eastwind investigation concluded that unlike the B-737s involved in the

United and USAir accidents, the Eastwind flight was moving at well over

the crossover airspeed,3 and thus maintained sufficient roll

control authority to overcome the effects of full rudder deflection.

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

\2\ On June 9, 1996, Eastwind fight 517, a B-737-2H5, was on a

regularly scheduled passenger flight from Trenton, New Jersey, to

Richmond, Virginia. While on approach to Richmond, the airplane

yawed abruptly to the right and then rolled to the right. The

captain immediately applied opposite rudder and left aileron. The

yaw/roll event slowed but the airplane was still attempting to roll

so the captain advanced the right throttle to compensate for the

roll with differential power. The airplane then appeared to move

back toward neutral for 1 or 2 seconds before abruptly returning to

a right bank. The flightcrew then disengaged the yaw damper system

and several seconds later the upset event stopped. The airplane flew

normally for the remainder of the flight. There were no injuries to

the 48 passengers or 5 crewmembers nor any damage to the airplane.

The FDR recorded the following 11 parameters: time, altitude,

airspeed, magnetic heading, engine pressure ratio (both engines),

microphone keying, roll attitude, control column position, and

longitudinal and vertical acceleration.

\3\ The crossover airspeed is the airspeed above which the

lateral control system (ailerons) of the B-737 can overcome the

aerodynamic forces caused by a rudder that has gone to a full

hardover position (full travel in one direction).

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

FAA Actions

Following piloted computer simulations of the USAir accident and

reports of malfunctions in the yaw damper system of B-737s, the FAA

issued two ADs requiring design changes to the rudder system on B-737

airplanes. To address possible rudder hardover scenarios and

uncommanded yaw damper movements, the FAA first issued AD 97-14-03 (62

FR 34623, June 27, 1997). That AD requires installation of a newly

designed rudder-limiting device to reduce rudder authority at flight

conditions where full rudder authority is not required; and

installation of a newly designed yaw damper system to improve system

reliability and fault monitoring capability. In response to the

possibility of a secondary slide jam and rudder reversal, the FAA next

issued AD 97-14-04 (62 FR 35068, June 30, 1997), which requires

installation of a new vernier control rod bolt and a new main rudder

PCU servo valve. The new servo valve is similar to the servo valve used

on B-737 Next Generation (NG) series airplanes (B-737-600, -700, -800,

and -900) and is designed to eliminate the possibility of a rudder

reversal.

Incident Investigation: 1991-1995

The NTSB investigated 28 B-737 incidents involving anomalous rudder

activity or uncommanded rolls between 1991 and 1995. Because all of the

airplanes involved were manufactured before May 26, 1989, under

Sec. 121.343(b) they were required to record only five parameters of

flight data. As a result, the NTSB lacked certain definitive

investigative criteria and had little more than the flightcrews'

subjective recollections to aid in determining a probable cause.

Safety Recommendations: 1995-1997

Between 1995 and 1997, while investigating the USAir accident, the

NTSB issued 20 safety recommendations dealing with the B-737; three of

those (A-95-25, A-95-26, and A-95-27) dealt specifically with upgrades

to the FDR for all B-737s. The NTSB stated that if either the United or

the USAir B-737 airplanes had recorded data on the flight control

surface positions, flight control inputs, and lateral acceleration,

that information would have allowed quick identification of any

abnormal control surface movements and configuration changes or

autopilot status changes that may have been involved in the loss of

control.

FAA Response: 1997 Regulations

In response to these safety recommendations, the FAA promulgated

revisions to the DFDR requirements for all airplanes. (Revisions to

Digital Flight Data Recorder Rules; Final Rule (62 FR 38362, July 17,

1997)) The revised DFDR regulations prescribe a maximum of 88

parameters to be recorded on flight data recorders, with the exact

number of parameters required to be recorded depending on the date of

airplane manufacture. For turbine-powered

[[Page 63142]]

transport category airplanes manufactured on or before October 11,

1991, and not equipped with a flight data acquisition unit (FDAU),\4\

14 CFR 121.344 and 125.226 require the recordation of 18 specified

parameters by August 20, 2001. For airplanes manufactured on or before

October 11, 1991, that were equipped with a FDAU, the regulations

require the recordation of 22 parameters by August 20, 2001. Airplanes

manufactured after October 11, 1991, are required to record 34

parameters by August 20, 2001. In some situations, compliance may

require the addition of sensors and wiring capable of recording the

specified parameters or a reprogramming of the current recorder to

accommodate the specified parameters. The 1997 DFDR regulations also

added a requirement for newly manufactured airplanes. Airplanes

manufactured after August 18, 2000, are required to record 57

parameters, and airplanes manufactured after August 19, 2002, are

required to record 88 parameters of flight data.

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

\4\ The flight data acquisition unit (FDAU) is an electronic

device that acquires data from sensors of various types (analog,

digital, pneumatic, etc.), translates the data into a digital

format, and transmits the data to the flight data recorder.

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

Further NTSB Findings

On March 24, 1999, the NTSB issued the final report of its

investigation into the crash of USAir flight 427. The NTSB determined

that the probable cause of the accident was a loss of control resulting

from the movement of the rudder surface position to its blowdown

limit.\5\ Furthermore, the NTSB stated that--

\5\ The rudder's blowdown limit is the maximum rudder deflection

available for an airplane at a given flight condition/configuration

and occurs when the aerodynamic forces acting on the rudder become

equal to the output force of the rudder's powered control actuator,

which is a function of the system hydraulic pressure.

the rudder surface most likely deflected in a direction opposite to

that commanded by the pilots as a result of a jam of the main rudder

PCU servo valve secondary slide to the servo valve housing offset

from its neutral position and overtravel of the primary slide.

Continuing Concerns

On February 23, 1999, USAirways Metrojet flight 2710, a B-737-2B7,

experienced an unexplained rudder hardover at cruise altitude. The

flightcrew reported that the airplane began to roll to the left

although the heading did not change. After the flightcrew disconnected

the autopilot, they noticed the right rudder pedal was forward of

neutral and that pressure on the left rudder pedal would not move the

rudder. The flightcrew regained normal rudder control only after the

standby rudder system was activated under prescribed USAirways'

procedures. The airplane made a successful emergency landing. The

preliminary results of kinematic analysis and computer simulations

using the Metrojet's FDR data indicate that the rudder traveled slowly

to its blowdown limit. To date, examinations of the Metrojet rudder

system have not revealed evidence of a failure or a jam of the servo

valve or other problem, such as a blockage in the rudder system

feedback loop, that would explain the uncommanded rudder hardover.

The NTSB recognized that the B-737 airplane has flown over 92

million hours since its initial certification in December 1967, and

that the airplane's accident rate is comparable to that of other

airplanes of a similar type. Nonetheless, the NTSB has concluded that

the redesigned rudder system does not eliminate the possibility of

other potential failure modes and malfunctions.

NTSB Recommendations

The NTSB concluded in its March 1999 report that the current

regulations for upgrading the DFDRs on existing airplanes are

inadequate because they do not require the recordation of specific

flight control information. Because several B-737 airplane rudder-

related events have been associated with the yaw damper system (which

moves the rudder independent of flightcrew input), the NTSB concluded

that it is important that yaw damper command (proposed parameter 90),

yaw damper status (proposed parameter 89), standby rudder status

(proposed parameter 91), and control wheel, control column, and rudder

pedal forces (current parameter 88) all be recorded on all B-737

airplanes. The NTSB also indicated that for optimal documentation, the

indicated parameters need to be sampled more frequently than is

currently required. The NTSB stated that by documenting the yaw

damper's operation and the resultant rudder surface movements, a yaw

damper event could be distinguished quickly from a flightcrew input or

a rudder anomaly. The NTSB considers this information critical in the

case of B-737 airplanes. The NTSB stated that if pilot flight control

input forces had been recorded on the United, USAir, or Eastwind FDRs,

the NTSB investigations would have been resolved more promptly and

actions taken to prevent similar events would have been hastened.

On April 16, 1999, the NTSB submitted the following recommendations

to the FAA regarding the recordation of additional parameters on B-737

DFDRs:

Recommendation No. A-99-28. Require that all B-737 airplanes

operated under part 121 or part 125 that currently have a FDAU be

equipped, by July 31, 2000, with a flight data recorder system that

records, at a minimum, the parameters required by the 1997 DFDR

regulations applicable to that airplane, plus the following parameters:

pitch trim, trailing edge flaps, leading edge flaps, thrust reverser

position (each engine), yaw damper command, yaw damper status, standby

rudder status, and control wheel, control column, and rudder pedal

forces. Yaw damper command, yaw damper status, and control wheel,

control column, and rudder pedal forces should be sampled at a minimum

rate of twice per second.

Recommendation No. A-99-29. Require that all B-737 airplanes

operated under part 121 or part 125 that are not equipped with a FDAU

be equipped, at the earliest time practicable, but no later than August

1, 2001, with a flight data recorder system that records, at a minimum,

the same parameters noted in Safety Recommendation No. A-99-28.

The NTSB also noted in its final report on the USAir accident that

B-737 flightcrews continue to report anomalous rudder behavior and the

NTSB considers it possible that another catastrophic event related to

the B-737 rudder upset could occur.

FAA Response

The FAA agrees with the intent of NTSB Safety Recommendation Nos.

A-99-28 and A-99-29. The agency shares the concern of the NTSB

regarding continuing reports of rudder-related incidents on B-737

airplanes and has initiated this rulemaking action.

The Proposed Regulations

The FAA is proposing that all B-737 model airplanes be required to

record the parameters listed in Sec. 121.344(a)(1) through (a)(22), and

(a)(88), plus three new parameters, to be designated as (a)(89) through

(a)(91), that would be added by this rulemaking. The new parameters

include yaw damper status, yaw damper command, and standby rudder

status. In addition, the sampling rate for the control forces listed in

current paragraph (a)(88) would be increased for B-737 airplanes.

Compliance Date Determinations

In its recommendation, the NTSB proposed that B-737 aircraft with

FDAUs be retrofitted to record the listed parameters by July 31, 2000,

and those

[[Page 63143]]

without FDAUs be retrofitted by August 1, 2001.

The FAA is proposing dates of August 18, 2000, and August 20, 2001,

respectively. The FAA notes that the compliance date for the 1997 DFDR

requirements is August 20, 2001. In an effort to streamline compliance

and facilitate planning by operators with mixed fleets, the dates in

this proposed regulation are the same (or comparable to) the date in

the 1997 regulations. These dates represent a change of less than three

weeks from the date recommended by the NTSB. The FAA has determined

that this brief delay is warranted in order to facilitate consistency

and efficiency in the regulations.

The FAA is aware that operators that have already upgraded their

airplanes to meet the 1997 regulations may have incurred out-of-service

costs from the additional downtime needed for installation. The FAA

does not have data indicating how many airplanes may already have been

retrofitted and thus would have to undergo another unscheduled

maintenance visit to comply with these proposed regulations.

Accordingly, the FAA is willing to consider an extension of the

compliance period, up to one year beyond the 2001 compliance date, for

those airplanes that installed a FDAU between July 16, 1996, and

November 18, 1999. The FAA seeks comment from those operators who would

benefit from such an extension, including specific information

regarding the number of airplanes that would be affected by this change

and the costs savings that would result from decreased downtime, as

opposed to complying by August 20, 2001. The FAA understands that

airplanes may have recently undergone an extended heavy maintenance

visit to install equipment to meet the 1997 regulations, and seeks to

mitigate the impact of this proposed rule if the savings would be

significant without undermining the intent of the regulations proposed

here. More detailed economic data is necessary to justify this further

extension.

Compliance Status Determination

The NTSB recommendations concerning the date for retrofit of B-737

airplanes is based on whether the airplane was equipped with a FDAU as

of the date of its recommendation, April 16, 1999. The 1997 DFDR

regulations use the date July 16, 1996 (the date of the NPRM for those

regulations), as the date for determining whether an airplane was

equipped with a FDAU. The FAA has determined that the 1996 date is more

appropriate for the requirements proposed here. The FAA is aware that

some operators, in an attempt to comply with the 1997 DFDR regulations

early, have already retrofitted B-737s in their fleets and have

installed FDAUs in airplanes that were not equipped with them in July

1996. Because airplanes with FDAUs would have to comply with these

proposed regulations 1 year earlier than non-FDAU airplanes, these

operators would be penalized by their early compliance with the 1997

DFDR upgrades. Accordingly, the FAA has determined that it is more

appropriate to use the July 16, 1996, date in this proposed regulation.

That date already is familiar to operators, will facilitate consistent

planning by affected operators, and will not penalize those operators

that chose to complete the 1997 DFDR upgrades before they were required

to do so.

In addition, as proposed above, the FAA is considering extending

the compliance date an additional year for those airplanes that were

upgraded with FDAUs between July 16, 1996 and November 18, 1999.

Accordingly, B-737 airplanes that were equipped with a FDAU on July

16, 1996, would be required to comply with the requirements proposed

here by August 18, 2000. Those B-737 airplanes that were not equipped

with a FDAU as of July 16, 1996, would have to comply by August 20,

2001. If the FAA receives sufficient data supporting such a change,

airplanes that were retrofitted to include a FDAU between July 16,

1996, and November 18, 1999, would have to comply by August 19, 2002.

Proposed Rule Changes

The FAA is concerned that the promulgation of new regulations

applicable only to B-737 airplanes may cause confusion since they

overlap the DFDR upgrade regulations promulgated in 1997 for all

airplanes operated under part 121 and part 125.

Proposed changes to the affected sections of part 121 are

summarized as follows:

Paragraph 121.344(b) applies to airplanes that were manufactured

before October 11, 1991, and requires the recordation of either 18 or

22 parameters of flight data, depending on whether the airplane had a

FDAU on July 16, 1996. Paragraph (b) would be amended by adding

language that excepts B-737 airplanes from this paragraph; all B-737

airplanes would instead be subject to the requirements listed in new

paragraph 121.344(m), discussed below.

Paragraph 121.344(c) applies to airplanes that were manufactured

before October 11, 1991, and were equipped with digital data buses and

certain FDAU equipment as of July 16, 1996. That paragraph requires the

recordation of 22 parameters of flight data. Paragraph (c) would be

amended by adding the same exception language for the B-737 that was

proposed for paragraph (b). All B-737 airplanes would instead be

subject to the requirements listed in new paragraph 121.344(m),

discussed below.

Paragraph 121.344(d) applies to airplanes that were manufactured

after October 11, 1991. That paragraph requires the recordation of 34

parameters of flight data, plus all other parameters that the airplane

is equipped to record. Language would be added to paragraph (d)

indicating that in addition to the requirements of (d), all B-737

airplanes must comply with paragraph 121.344(m). Because the

requirements of paragraphs (d) and (m) do not overlap completely,

compliance with both would be required. The compliance dates for the

two paragraphs remain separate. Essentially, a B-737 airplane covered

by paragraphs (d) and (m) would have to install the parameters listed

in paragraphs (a)(1) through (a)(22), plus paragraphs (a)(88) through

(a)(91) by August 18, 2000, since they already have FDAUs. The

parameters listed in paragraphs (a)(23) through (a)(34) would not have

to be installed before August 20, 2001, under the requirements of

paragraph (d). This is the only category of B-737s for which a dual

compliance date would exist. The FAA anticipates that most operators of

B-737s would choose to install all of the required equipment at the

same time.

Paragraph 121.344(e) applies to airplanes that will be manufactured

after August 18, 2000. Paragraph (e) requires the recordation of 57

parameters of flight data, plus all other parameters that the airplane

is equipped to record. Similar to paragraph (d), language would be

added to paragraph (e) indicating that in addition to the requirements

of (e), all B-737 airplanes must comply with paragraph 121.344(m).

Because the requirements of paragraphs (e) and (m) do not overlap

completely, compliance with both would be required. In order to comply

with both paragraphs, a B-737 airplane manufactured after August 18,

2000, must go into service recording the parameters listed in

paragraphs (a)(1) through (a)(57) and (a)(88) through (a)(91), plus all

other parameters that the airplane is equipped to record.

Paragraph 121.344(f) applies to airplanes that will be manufactured

after August 19, 2002. That paragraph requires the recordation of 88

[[Page 63144]]

parameters of flight data, plus all others parameters that the airplane

is equipped to record. Similar to paragraph (e), language would be

added to paragraph (f) indicating that in addition to the requirements

of paragraph (f), all B-737 airplanes must comply with paragraph

121.344(m). Because the requirements of paragraphs (f) and (m) do not

overlap completely, compliance with both would be required. In order to

comply with both paragraphs, a B-737 airplane manufactured after August

19, 2002, must go into service recording the parameters listed in

paragraphs (a)(1) through (a)(91), plus all other parameters that the

airplane is equipped to record.

All paragraphs of current Sec. 121.344 not specifically amended by

this rulemaking would continue to apply to all B-737 airplanes.

New Paragraph 121.344(m)

The proposed rule contains a new paragraph 121.344(m) that would

apply to all B-737 airplanes operated under part 121. The parameters

required to be recorded under paragraph (m) would be either an

alternative or an addition to the other recording requirements of

Sec. 121.344 for an airplane of a particular age and having particular

equipment installed, as explained above.

The introductory text of proposed paragraph (m) states that all B-

737 airplanes must record the parameters listed in paragraphs (a)(1)

through (a)(22) and (a)(88) through (a)(91) in accordance with the

ranges, accuracies, resolutions, and recording intervals specified in

appendix M to part 121. This language introduces two requirements that

were not included in the 1997 DFDR upgrade regulations.

First, under the 1997 DFDR regulations, B-737 airplanes that were

not equipped with FDAUs did not have to have FDAUs installed to meet

those regulations. However, the FAA anticipates that FDAUs will, in

many cases, be necessary in order to meet the recording requirements

established in paragraph (m) and appendix M.6 Second, B-737

airplanes that were covered under Sec. 121.344(b) had to record the

designated parameters in accordance with the rates, ranges, and

accuracies specified in appendix B to part 121. Under this proposal,

those airplanes would have to record the parameters listed in paragraph

(m) in accordance with appendix M rather than appendix B. Appendix M

contains more stringent requirements than appendix B for recording

rates and accuracies, and may require equipment upgrades.

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

\6\ If an operator chooses instead to add a second flight data

recorder, a FDAU may not be necessary because sufficient recording

capacity would exist.

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

The proposed compliance dates for the requirements of paragraph (m)

are in given in paragraphs (m)(1) and (m)(2). Paragraph (m)(1) provides

that all B-737 model airplanes equipped with a FDAU of any type as of

July 16, 1996, must comply with the requirements of paragraph (m) by

August 18, 2000. Paragraph (m)(1) also provides that B-737 airplanes

manufactured after July 16, 1996, must comply with the requirements of

paragraph (m) by August 18, 2000. Without the manufacturing date

provision, airplanes manufactured after the date specified (July 16,

1996) would have no specified compliance date. This requirement

presumes that B-737s manufactured after July 16, 1996, are equipped

with FDAUs and thus would be subject to the August 18, 2000, compliance

date.

Paragraph (m)(2) states that all B-737 model airplanes that were

not equipped with a FDAU of any type as of July 16, 1996, must comply

with the requirements of paragraph (m) by August 20, 2001.

FDAU Equipment

A FDAU is an electronic device that acquires data from sensors of

various types, translates the data into a digital format, and transmits

the data to a flight recorder. The FAA has received numerous questions

regarding the meaning of a ``FDAU of any type,'' as used in the

regulations. In some cases, operators have sought to delay compliance

with the 1997 DFDR regulations or change the applicability of the

regulations based on the equipment installed in their airplanes. The

term FDAU is intended to refer to any piece of equipment installed on

an airplane that functions as a data acquisition unit. A particular

piece of equipment need not have a nameplate designating it as, or be

marketed or sold as, a ``flight data acquisition unit'' in order to be

considered a FDAU for purposes of these regulations if it functions as

described. Further, a combination unit that is capable of FDAU

functions would be considered a FDAU for purposes of both current and

proposed regulations.

Compliance Dates

With some minor variation, as described above, the FAA has agreed

to the compliance schedule recommended by the NTSB for retrofit of B-

737s to record the flight data proposed in this rulemaking. The FAA

agrees with the NTSB that operators have less to accomplish in a

retrofit of airplanes that had FDAUs installed as of July 16, 1996,

than they do for airplanes that have never had FDAUs. Accordingly, a B-

737 that had a FDAU installed on July 16, 1996, must comply with the

requirements of paragraph (m) by August 18, 2000. A B-737 airplane that

did not have a FDAU installed as of July 16, 1996, and does not have a

FDAU installed as of the date of this NPRM must comply with the

requirements of paragraph (m) by August 20, 2001. A B-737 airplane not

equipped with a FDAU on July 16, 1996, but equipped with a FDAU as of

the date of this NPRM, must comply with paragraph (m) by August 19,

2002.

The reasons for the change to the NTSB's recommended dates for

compliance and for determining FDAU status were discussed above.

The New Parameters

Flight Control Input Forces

The parameter listed in paragraph (a)(88) is described as ``[a]ll

cockpit flight control input forces (control wheel, control column,

rudder pedal).'' These control input forces are the center of the

NTSB's recommendation and comprise data that the NTSB has stated is

critical to a more complete investigation of accidents and incidents

concerning loss of control of airplanes.

This parameter was added in the 1997 amendment to the DFDR

regulations, but within the last few months has become a source of

disagreement as to where these forces must be measured. The FAA has

received inquiries from the NTSB and Boeing concerning an acceptable

means of recording rudder pedal forces. These are discussed below.

Actions by Boeing

In 1996, in response to the proposed DFDR upgrade regulations,

Boeing began to develop the equipment and instructions necessary to

comply with paragraph (a)(88). In designing a rudder pedal force

transducer (a specific type of sensor), Boeing's primary concern was to

identify whether the input was coming from the forward or the aft end

of the system; that is, whether the input was coming from the cockpit

or the rudder assembly itself.

Boeing developed a transducer that is placed ``midstream'' in the

rudder control system. This specific transducer and its location were

driven by the need for the equipment to be retrofitted or installed (on

the assembly line) on every design in the Boeing fleet. Boeing's

research indicated that a force transducer placed on the rudder pedals

themselves could require significant structural redesign of existing

airplanes.

[[Page 63145]]

Finally, Boeing was looking for a design and installation that it could

develop quickly to meet the needs of operators for compliance with the

1997 DFDR regulations, and that would require the least amount of

structural disassembly to install.

The first rudder force transducer was designed for the B-737 NG

series airplanes. Although the NPRM for the 1997 regulations (published

in July 1996) drove the initial design and timing, Boeing realized that

whatever design it settled on would have to work on all of its airplane

models.

Boeing currently has available two service bulletins addressing the

installation of the rudder force transducer on in-service B-737s. The

service bulletin for the B-737-300, -400, and -500 series was released

April 15, 1999; the bulletin for the B-737-600, -700, and -800 series

was released May 20, 1999. The bulletin for the B-737-100 and -200

series airplanes is in development. In mid-June 1999, Boeing reported

that it had approximately 1,000 rudder transducer retrofit kits

available, and that for the time being, they were being offered free of

charge in order to encourage installation. Boeing stated that few kits

had been requested at that time.

NTSB Opinion

The NTSB's April 1999 recommendation indicated only that it wanted

the control forces recorded, without specifying a means for doing so.

In conversations with NTSB staff in May 1999, it became evident to the

FAA that the NTSB would prefer a system that measured the rudder input

force at the pedals themselves, an addition of four transducers rather

than the one already designed by Boeing. Subsequent discussions between

the FAA and the NTSB indicated that the Board is of the opinion that

only the installation of four rudder pedal force sensors would meet the

intent of its April 16, 1999, recommendation to record rudder input

force.

FAA Response

In response to the NTSB's expressed preference, the FAA requested

that Boeing estimate the amount of time and cost involved in placing

force sensors on each of the four rudder pedals of all B-737 airplanes.

By letter dated May 26, 1999, Boeing estimated that it would take

approximately 18 to 24 months to develop a service bulletin for the

installation of four rudder pedal force transducers. In addition,

Boeing estimates that it would take an additional 6 months before

retrofit kits to install the transducers would be available.

Boeing also indicated that it does not currently have a viable

design solution for the four rudder pedal transducer option that does

not involve ``major under floor structural modification,'' that would

affect the entire fleet of B-737 airplanes. In conversations with

Boeing staff, it was thought that as little as one inch of clearance

was available under the rudder pedals, and that additional equipment

installed at that location could require that one of the floor beams be

moved. Boeing was not immediately able to indicate the estimated costs

of such a modification, but the description implies that the cost would

be substantial.

The time estimated by Boeing to reengineer the B-737 for four

rudder pedal transducers is well beyond the installation dates

recommended by the NTSB. Moreover, the fact that the four rudder pedal

transducer option might require significant redesign of the airplane

structure suggests that the cost of such a modification would be

extraordinary.

In a presentation to the FAA and the NTSB in May 1999, Boeing

indicated that the rudder transducer data, alone or in combination with

other flight recorder data, will satisfy almost all of the concerns

expressed by the NTSB for flight control data. The FAA acknowledges

that choices have to be made when deciding what equipment is feasible

for installation and the level of data that can be provided by

different installations.

The FAA acknowledges that there is a difference in the exact nature

of the data acquired using Boeing's approved single transducer system

and the NTSB's preferred four-pedal sensor retrofit. However, without a

better understanding of the incremental benefits the particular data

that the four-pedal sensor option would provide and a better estimate

of the time and cost that would be required for installation, the FAA

cannot decide which option provides the most overall benefit.

The FAA specifically requests comment on the necessity and

feasibility of instrumenting all four rudder pedals on B-737 airplanes

with force sensors as a means of compliance with paragraph (a)(88).

While the FAA has found Boeing's single force transducer to be

acceptable for monitoring rudder pedal force, it requests comment on

whether this should remain an accepted means of compliance for all B-

737 airplanes that have not yet installed the single transducer or

otherwise complied with paragraph (a)(88).

If the FAA finds, in light of the comments received, that the four-

pedal sensor retrofit is the only way available to determine the source

of suspected uncommanded rudder movement, and that any incremental

increase in cost and time required to accomplish this retrofit will

provide a justifiable benefit, the FAA will propose it as an

alternative for B-737 airplanes that have not otherwise complied with

paragraph (a)(88) as of November 18, 1999. Any proposal would include

an analysis of the costs and benefits of that configuration.

The FAA notes that for the purpose of determining an estimated cost

of these proposed regulations, the data for the single Boeing

transducer was used for compliance with paragraph (a)(88) because it

was the only information available. Those estimates are presented in

detail in the regulatory evaluation section of this document. The FAA

requests cost data for the four-pedal retrofit, described above, in

order to determine whether the incremental increase in benefits that

would be provided by that configuration are offset by the additional

time and cost that would be needed for compliance.

Measuring Other Control Forces

Paragraph (a)(88) also requires the measurement and recordation of

control wheel and control column input forces. While these two

measurements have not received the level of attention focused on rudder

pedal forces, the FAA understands that there are issues of acceptable

means of measuring these forces as well. The FAA specifically requests

comment on the means and costs of measuring these control forces under

the requirements proposed in this rulemaking.

Change to Current Parameter 88

The NTSB also recommended that control input forces be measured

more frequently for B-737 airplanes. This recommendation is being

proposed as a change to the sampling interval that would apply to the

B-737 only, and would require that control forces be sampled twice per

second. This requirement would be added in appendix M, parameter 88, by

means of a footnote specifying a shorter interval for B-737 airplanes

only. The sampling interval for that parameter would remain unchanged

for all other aircraft. Similarly, the text in the ``Remarks'' column

for parameter 88 would remain applicable to other aircraft, but would

not apply to B-737 airplanes.

[[Page 63146]]

Yaw Damper Status

Proposed paragraph (a)(89) would add the recordation of yaw damper

status. The intent of this requirement is to record whether the yaw

damper is on or off. As described previously, the yaw damper system

moves the rudder independent of flightcrew input, and has become a

concern in the continuing occurrence of rudder-related incidents.

Yaw Damper Command

Proposed paragraph (a)(90) would add the recordation of yaw damper

command. The intent of this is to record the amount of voltage being

received by the yaw damper system, which determines how much rudder

movement is being commanded. This is an automatic system that is not

controlled by cockpit commands, except to turn the system on or off.

The flightcrew does not necessarily know what the system is doing since

the rudder movement does not feed back through the rudder pedals.

Standby Rudder Status

Proposed paragraph (a)(91) would add the recordation of standby

rudder status. The standby rudder system is an alternative source of

hydraulic power to the rudder that is used when primary hydraulic power

is lost. The intent of this requirement is to record whether the

standby rudder system switch is in the on or off position.

Changes to Part 125

The changes proposed for part 121 are also proposed for the

corresponding sections of part 125. Specifically, the changes made to

Sec. 121.344 also would be made to Sec. 125.226. The changes made to

appendix M to part 121 would also be made to appendix E to part 125.

One additional change would be made to part 125. The FAA has

determined that for purposes of flight data recordation, there is no

difference between a large airplane operated under part 121 and one

operated under part 125, or operated under part 91 under deviation

authority from part 125. Accordingly, the FAA has determined that

aircraft that are operating under deviation authority from part 125

must still comply with the flight data recorder requirements of part

125 for the particular aircraft. This requirement would apply to all

aircraft, not just the B-737.

This requirement is proposed as a new paragraph 125.3(d), which

indicates that no deviation authority from the flight data recorder

requirements would be granted, and that any previously issued deviation

from the FDR requirements of part 125 would no longer be valid. Section

91.609 also will be amended to reflect this requirement.

Any person who operates under deviation authority from part 125

would be subject to the FDR requirements of part 125 applicable to the

particular aircraft as of the date of the final rule adopting these

proposed regulations. For B-737s, compliance would be required as

described in this proposed rule. For all other aircraft, compliance

would be required as specified in the applicable subsections of

Secs. 125.225 or 125.226. An aircraft subject to Sec. 125.226 would

have to upgrade its FDR system to meet the requirements of that

paragraph by the date specified in the applicable paragraph of that

regulation.

For persons operating using deviation authority from part 125, this

would be a retrofit requirement, and no current holders of letters of

deviation would be ``grandfathered.'' This NPRM serves as notice to

current holders of letters of deviation that their deviation authority

would be amended pursuant to paragraph 125.3(b).

The FAA specifically requests comments addressing why the flight

data recorder requirements of part 125 should not be made applicable to

aircraft operated under deviation authority. The FAA also specifically

requests comments from affected persons operating their aircraft under

deviation authority from part 125 concerning the compliance dates

proposed above. If the proposed compliance dates cannot be met, reasons

why they cannot be met and acceptable alternatives should be submitted

as part of the comment.

Table 1.--Rule Changes and Compliance Dates

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

Number of Number of

Manufacture date/ parameters 1997 rule parameters

Current rule paragraph FDAU status in required in the compliance date proposed for B-

1996 1997 rule 737s

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

121.344(b)...................... Before 1991/no 18................ 8/1999 through 8/ 26 by 8/2001, FDAU

FDAU. 2001. necessary.

121.344(b)...................... Before 1991/FDAU.. 22................ 8/1999 through 8/ 26 by 8/2000.

2001.

121.344(c)...................... Before 1991/FDAU 22 plus any 8/2001............ 26 by 8/2000.

plus data bus. capable.

121.344(d)...................... After 1991/with 34 plus any 8/2001............ 38 by 8/2000.

FDAU. capable.

121.344(e)...................... After 2000/with 57 plus any 8/2000............ 61 at manufacture.

FDAU. capable.

121.344(f)...................... After 2002/with 88................ 8/2002............ 91 at manufacture.

FDAU.

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

Paperwork Reduction Act

This proposal contains information collection requirements. As

required by the Paperwork Reduction Act of 1995 (44 U.S.C. 3507(d)),

the Department of Transportation has submitted the information

collection requirements associated with this proposal to the Office of

Management and Budget for its review.

Title: Revisions to Digital Flight Data Recorder Regulations for

Boeing 737 Airplanes and for Part 125 Operations.

This notice proposes to amend the regulations to add a requirement

for all B-737 series airplanes to record additional flight data

parameters. The additional parameters to be recorded are not required

by the current regulations and would provide the only currently

available means of gathering information that the FAA and the NTSB

anticipate will help assess the cause of continuing incidents that

appear to be related to rudder anomalies on B'737 airplanes.

The respondents are all U.S. certificate holders operating B'737

airplanes under parts 91, 121, 125, and 129.

The required information is electronically recorded on the FDR each

time the airplane begins its takeoff roll until it has completed its

landing roll and must be kept until the airplane has been operated for

25 hours. The recorded data are overwritten on a continuing basis and

are only accessed following an accident. This requirement is a nominal

addition to a passive information collection activity and therefore

does not contain a measurable hour burden. However, for purposes of the

submission to OMB, the FAA has assigned a one hour burden to the

request. The measurable burden

[[Page 63147]]

associated with this NPRM is the cost to the respondents. The breakdown

associated with the cost can be found in the regulatory evaluation

summary below.

The agency is soliciting comments to: (1) Evaluate whether the

proposed collection of information is necessary for the proper

performance of the functions of the agency, including whether the

information will have practical utility; (2) evaluate the accuracy of

the agency's estimate of the burden; (3) enhance the quality, utility,

and clarity of the information to be collected; and (4) minimize the

burden of the collection of information on those who are to respond,

including through the use of appropriate automated, electronic,

mechanical, or other technological collection techniques or other forms

of information technology (for example, permitting electronic

submission of responses).

Individuals and organizations may submit comments on the

information collection requirement by December 20, 1999, to the address

listed in the ADDRESSES section of this document.

According to the regulations implementing the Paperwork Reduction

Act of 1995 (5 CFR 1320.8(b)(2)(vi)), an agency may not conduct or

sponsor, and a person is not required to respond to, a collection of

information unless an agency displays a current valid OMB control

number. The OMB control number for this information collection will be

published in the Federal Register after it is approved by the Office of

Management and Budget. It should be noted that OMB approval for the

activity described above would be for a modification of the existing

collection of information for digital flight data recorders under OMB

control number 2120-0616.

Compatibility With ICAO Standards

In keeping with U.S. obligations under the Convention on

International Civil Aviation, it is FAA policy to comply with

International Civil Aviation Organization (ICAO) Standards and

Recommended Practices to the maximum extent practicable. The FAA

determined that there are no ICAO Standards and Recommended Practices

that correspond to these proposed regulations.

Regulatory Evaluation

Proposed changes to Federal regulations must undergo several

economic analyses. First, Executive Order 12866 directs that each

Federal agency shall propose or adopt a regulation only upon a reasoned

determination that the benefits of the intended regulation justify its

costs. Second, the Regulatory Flexibility Act of 1980 requires agencies

to analyze the economic impact of regulatory changes on small entities.

Third, the Office of Management and Budget directs agencies to assess

the effects of regulatory changes on international trade. Fourth, the

Unfunded Mandates Reform Act of 1995 (Public Law 104-4) requires

agencies to prepare a written assessment of the costs, benefits, and

other effects of proposed or final rules that include a Federal mandate

likely to result in the expenditure by State, local, or tribal

governments, in the aggregate, or by the private sector, of $100

million or more annually (adjusted for inflation). In conducting these

analyses, the FAA has determined that this proposed rulemaking: (1)

Would be a ``significant regulatory action'' as defined in Executive

Order 12866 or as defined in DOT's Regulatory Policies and Procedures;

(2) would have a significant economic impact on a substantial number of

small entities; (3) would have minimal effects on international trade;

and (4) would not contain a significant intergovernmental mandate but

would contain a significant private sector mandate. These analyses,

contained in the document Initial Regulatory Evaluation of the

Revisions to Digital Flight Data Recorder Rules for Boeing 737

Airplanes and for Part 125 Operations, which has been placed in the

docket, are summarized as follows.

Request for Comments

The FAA requests comments on any and all of its assumptions,

methodology, and data used in its economic analyses. The FAA also

requests that commenters provide supporting data for their comments.

Data Sources

The principal means of obtaining data for this analysis has been

discussions with representatives from Boeing, several airlines that

operate Boeing 737s, manufacturers of FDRs and FDAUs, and repair

stations that would perform FDR system retrofits. In addition, the Air

Transport Association surveyed its members and provided the FAA with

data concerning potential compliance costs and out-of-service time that

would be associated with the proposed rule. As may be expected, there

were some differences in the various estimates. In choosing among these

estimates, the FAA has generally selected the median estimates.

Affected Industries

The FAA has estimated that the proposed rule would require that

1,306 U.S.-registered B-737s have their FDR systems retrofitted to

record additional flight data parameters. It would further require

these additional flight data parameters to be recorded in an estimated

2,144 newly manufactured U.S.-registered B-737s during the 20 years

following the promulgation of the proposed rule. Twenty-four U.S. air

carriers, 3 foreign U.S. air carriers, and 16 non-air carrier private

owners currently operate U.S.-registered B-737s. The proposed rule

would also affect transport category airplanes other than B-737s that

are operating under part 91 on a deviation authority from part 125.

However, as those costs and benefits for this latter group were

included in the regulatory evaluation for the FAA's 1997 Digital Flight

Data Recorder Rulemaking, they are not again evaluated in this proposed

rule. Finally, the proposed rule would affect Boeing's future

production B-737s.

Benefits

The principal benefit from increasing the number of flight data

parameters recorded would be the increased probability that a future B-

737 accident or incident investigation would uncover a previously

unknown cause that would not have been discovered in the absence of

these additional parameters being recorded. The discovery of this

cause, in turn, could lead to corrective actions (for example, an

airplane design modification or changes in operating procedures) that

would help to prevent similar accidents. As there have been few B-737

accidents whose causes could not be determined (two such accidents in

about 92 million B-737 flight hours), the FAA has evaluated the

benefits and costs of the proposed rule over a 20-year time period.

In order to quantify the potential benefits of a prevented B-737

accident, the FAA has used the following values: $2.7 million for each

prevented fatality and an average of 96 passengers and crew on a B-737,

for a resulting total of $259.2 million per airplane; $20 million for a

destroyed B-737; $5 million for ancillary damage to ground structures;

and $31 million for the resultant government and industry accident

investigation. Thus, the average potential benefit from preventing a B-

737 in-flight accident would be about $315.2 million.

Compliance Costs

Summary

B-737 operators would incur nearly all of the costs imposed by the

proposed rule. These costs would be comprised of both one-time first-

year costs and

[[Page 63148]]

recurring annual costs. As described in the following paragraphs, the

FAA has estimated that the present value of the total costs of

compliance with the proposed rule would be about $205.3 million. Of

that expenditure, about $158.6. million would be first-year costs to

retrofit the current B-737 fleet that would be spent by August 20,

2001. The present value of the increased costs of manufacturing future

B-737s over the next 20 years would be about $40.4 million and the

present value of the increased annual costs of additional fuel and

maintenance of B-737s during the next 20 years would be $6.3 million.

As previously discussed, the FAA revised the flight data recorder

rules for many airplanes, including B-737s, in 1997. In the Final

Regulatory Evaluation for that final rule, the FAA estimated at that

time that the present value in 1997 of the costs to comply with those

revision was about $48 million (which is equivalent to $58.8 million in

year 2000 present value terms) for B-737 airplane operators and

Boeing.7

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

\7\ The present value of the total compliance costs for all

airplanes affected by the 1997 revisions was estimated to be about

$316.3 million (about $387.5 million in year 2000 present value

terms).

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

Consequently, if those revisions and this proposed rule are viewed

as two parts of one rulemaking extended over time, the FAA has

estimated that the present value of the overall compliance costs with

these two parts would be about $264.1 million for the B-737 operators

and for Boeing.

The per-airplane retrofitting costs for only this proposed rule are

have been summarized in Table 2 by B-737 series and by type of FDR

system. As can be seen, the individual airplane costs can vary widely;

the reasons underlying these differences are discussed in the following

paragraphs.

Table 2.--Per-Airplane Compliance Cost by 737 Series and FDR System

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

Out-of-

737 series Equipment and labor service Out-of-service lost Total costs and lost

costs days net revenue net revenue

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

200.............................. $160,200-$176,400 4-7 $250-$800 $160,450-$177,200

200--Advanced (No FDAU).......... 160,200-176,400 4-7 4,900-8,600 165,100-185,000

200--Advanced (FDAU)............. 68,800-90,000 2-4 2,450-4,900 71,250-94,900

300 (No FDAU).................... 175,200-191,400 6-9 20,375-30,550 195,575-221,950

300 (FDAU)....................... 35,100-90,000 2-4 6,800-21,550 41,900-111,550

400 (No FDAU).................... 160,200-176,400 6-9 17,350-30,350 177,550-206,750

400 (FDAU)....................... 35,100-90,000 2-4 8,675-25,250 43,775-115,250

500 (No FDAU).................... 175,200-191,400 6-9 20,150-30,200 195,350-221,600

500 (FDAU)....................... 35,100-90,000 2-4 6,700-19,100 41,800-109,100

600.............................. 35,100 2-4 15,375-30,750 50,475-65,850

700.............................. 35,100 2-4 17,350-34,675 52,450-69,775

800.............................. 35,100 2-4 20,800-41,575 55,900-76,675

900.............................. 35,100 2-4 21,950-43,875 57,050-78,975

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

If the 1997 flight data recorder revisions and this proposed rule

are viewed as two parts of one rulemaking extended over time, then the

per B-737 compliance costs associated with the previous revisions need

to be included. However, that Regulatory Evaluation did not

disaggregate the compliance costs for individual B-737 series. As a

result, the FAA has calculated in the Initial Regulatory Evaluation for

this proposed rule that the per B-737 compliance costs associated with

the 1997 revisions would be about $45,000.

One-time Compliance Costs to Retrofit B-737s

Types of One-time Compliance Costs

The one-time first-year costs to retrofit B-737s would be: (1) The

time to engineer new designs for the retrofitted FDR systems; (2) the

equipment and labor costs to retrofit the FDR systems; and (3) the lost

net revenue while the airplanes are out of service for a retrofit.

Time to Engineer New Designs for the Retrofitted FDR Systems

There are two general types of engineering design costs associated

with the proposed rule. The first type is the manufacturer's or

airline's engineering time required to design the FDR system including

the parts (that is, the FDR and the FDAU) to be used in a retrofitted

B-737 FDR system. The second type is the engineering time required for

the airline or repair station to obtain an FAA Supplemental Type

Certificate (STC)/Parts Manufacturing Approval (PMA) for the revised

FDR system.

With respect to the FDR manufacturers' engineering costs, industry

has reported that the increased number of recorded flight data

parameters would require that a solid state FDR (installed to comply

with the 1997 DFDR regulations) with a memory capacity of 64 words per

second (wps) would need to be increased to 128 wps. This increase would

involve a software change that would require FAA approval. The FAA has

estimated that these one-time FDR engineering costs would be about

$5,000 per airline per B-737 series. The FAA has further estimated that

about 40 of these FDR approvals would be required, for a total one-time

engineering cost of about $200,000 for the upgraded FDRs.

Although the proposed rule would not specifically mandate a FDAU in

every B-737, airline and repair station avionics engineers were

unanimous in stating that retrofitting an airplane with a FDAU would be

less expensive than retrofitting it with a second FDR system (and

coordinating it with the first FDR system) to record the additional

flight data parameters. Consequently, the FAA has assumed that an owner

of a B-737 that does not have a FDAU would have the FDAU retrofitted in

order to keep the airplane in service. Unlike upgrading FDR memory,

installing a FDAU would be a substantial modification to the airplane

and a FDAU manufacturer has estimated that obtaining FAA approval to

integrate its FDAU in an FDR system would take between 16 and 26 weeks

and would cost about $200,000 for each airline B-737 series/FDAU

combination. However, the FAA has determined that after about five such

approvals, a manufacturer could use commonality demonstrations to

reduce this estimated time to between 8 and 12 weeks and reduce the

estimated cost to about $25,000. It should be noted that several of

these applications can be submitted at one time and the applicant would

not wait for one airline's FDAU approval

[[Page 63149]]

before submitting the next airline's FDAU for approval. The FAA has

estimated that about 40 of these FDAU approvals would be required, for

a total one-time engineering cost of about $2.75 million for the FDAU

approvals.

With respect to airline or repair station engineering time to

obtain an FDR system STC, its engineering staff would need to redesign

the entire FDR system, ground test it, flight test it, and submit the

drawings and data to the FAA. Airlines have reported that it would take

anywhere from 3 months to 1 year to complete the entire engineering/FAA

approval process. However, the FAA is concerned that the higher

estimates may reflect the worst case. Based on airline reports, the FAA

has determined that 4 months would be the average amount of time needed

for the entire process. The FAA also has estimated that three industry

engineers would work full time on each STC approval. The FAA has used

an engineer hourly compensation rate of $100, which includes salary and

fringe benefits plus a markup for the hours spent by supervisors,

management, legal, etc. Thus, the FAA has estimated that each STC

application would cost about $200,000. The FAA has further estimated

that about 32 of these STC applications would be made. Thus, the FAA

has estimated that the one-time engineering cost for the FDR system STC

applications would be about $6.4 million.

Thus, the FAA has estimated that the total one-time engineering

costs for obtaining FAA-approved equipment and STCs would be about

$9.15 million and would take about 5 months.

Equipment and Labor Costs to Retrofit FDR Systems

The cost of an individual FDR system retrofit will depend on

existing equipment and the number of flight data parameters currently

recorded on any one airplane. In general, the FDR system components

that would be affected by the proposed rule would be the FDR, FDAU,

sensors, and wiring.

As noted earlier, the FAA has relied upon industry estimates for

the FDR system equipment costs and for the amount of labor time to

complete these retrofits. However, the FAA has not used the actual

industry labor rates. Instead, the FAA has developed an airplane

mechanic hourly compensation rate of $75, which includes salary and

fringe benefits plus an adjustment for the otherwise unaccounted hours

spent by engineers, supervisors, management, etc., during an FDR system

retrofit.

With respect to the FDRs, the FAA has estimated that 156 B-737s

would have their FDRs replaced whereas the remaining 1,150 B-737s would

have their FDRs upgraded with additional memory. The FAA has determined

that a new FDR would cost about $25,000; upgrading the memory of an

older FDR that records 18 flight data parameters would cost about

$10,000; upgrading the memory of an older FDR that records 22 flight

data parameters would cost about $5,000; and upgrading the memory of a

newer FDR that records more than 22 parameters would cost about $1,900.

Although all FDR systems have an FDR, it would take more labor time to

install a new recorder than to upgrade an FDR's memory because the

former action would involve more FDR system testing and verifications

than would the latter.

Consequently, the FAA has estimated that upgrading to a new

recorder would require 32 labor hours to remove the old recorder and to

install and to test the new recorder. However, upgrading an FDR would

require 16 labor hours because less testing of the FDR system would be

needed. Thus, the FAA has estimated that the present value of the

equipment cost for replaced or upgraded FDRs would be about $17.2

million.

With respect to the FDAUs, the FAA has estimated that a FDAU would

need to be retrofitted into 496 B-737s, whereas the existing FDAUs in

810 B-737s would need to be reprogrammed. In this case, ``FDAU

reprogramming'' would involve both hardware modifications and software

revisions.

Retrofitting a B-737 with a FDAU would necessitate a complete

rerouting of the FDR system wiring because the recorder itself (where

the wires formerly terminated) is located in the back of the airplane,

while the FDAU would be located in the front of the airplane. Thus, the

wiring would now run from the sensors to the FDAU and then back to the

recorder. The FAA has determined that a new FDAU would cost about

$50,000 while reprogramming an existing FDAU would cost about $10,000.

Relying primarily on estimates provided by airlines that have

retrofitted FDAUs into their B-737s, the FAA has estimated that this

retrofitting would take about 200 labor hours, which includes the

associated labor hours to rewire the existing FDR system. The FAA also

has estimated that the labor hours to remove, ship to the manufacturer,

reinstall, and test a reprogrammed FDAU would take 48 hours for an

older FDAU and about 40 hours for a newer FDAU. On that basis, the FAA

has estimated that the present value of the FDAU equipment and

associated labor costs would be about $37.6 million.

With respect to the additional sensors and wiring, the FAA has

divided the equipment and labor costs into two components: (1) The

equipment and labor costs to add flight data parameters (a)(19) through

(a)(22); and (2) the equipment and labor costs to add the proposed new

flight data parameters (a)(89) through (a)(91) and to add flight data

parameters found in (a)(88) with the proposed increased sampling rates.

The FAA estimates of the costs of sensors and wiring to add

parameters (a)(19) through (a)(22) is based on industry sources that

have reported that the sensors to supply the additional flight data

parameters to be recorded by the FDR generally cost between $200 and

$2,000 each. These additional sensors would also require the addition

of wiring to transmit their inputs to the FDAU. The FAA has estimated

that the total cost of the sensors and wiring for a B-737 FDR system to

add parameters (a)(19) through (a)(22) would be about $20,000.

The FAA has primarily used the estimated labor hours supplied by

airlines that have retrofitted flight data parameters (a)(19) through

(a)(22) in their B-737s to estimate these costs. On that basis, the FAA

has estimated that, in addition to the 200 labor hours associated with

the FDAU rewiring, rewiring the sensors and wiring for flight data

parameters (a)(19) through (a)(22) would take 200 labor hours for a B-

737-200, an Advanced B-737-200, or a B-737-400 and 400 labor hours for

a B-737-300 or a B-737-500. Thus, the labor costs of adding flight data

parameters (a)(19) through (a)(22) would be about $15,000 for a B-737-

200, an Advanced B-737-200, or a B-737-400, while it would be about

$30,000 for a B-737-300 or a B-737-500.

Thus, the FAA has estimated that the equipment and labor costs of

adding flight data parameters (a)(19) through (a)(22) would be about

$35,000 for a B-737-200, an Advanced B-737-200, or a B-737-400 while it

would cost about $50,000 for a B-737-300 or a B-737-500.

The primary difficulty in estimating the potential labor hours to

retrofit proposed flight data parameters (a)(89) through (a)(91) is

that these flight data parameters have not previously been recorded in

any B-737. As a result, no engineering analysis has been completed that

can serve as an experienced basis for an estimate. Consequently, the

FAA has adopted some preliminary industry estimates that it would cost

about $22,000 for the additional sensors and wiring to retrofit flight

data parameters (a)(88) at a higher sampling rate and flight data

parameters

[[Page 63150]]

(a)(89) through (a)(91) in a B-737 FDR system that now records at least

22 flight data parameters. In addition, the FAA has estimated that this

retrofit would involve about 360 labor hours. On that basis, the FAA

has estimated that these labor costs would be about $27,000 per

airplane.

Thus, the FAA has estimated that the per-airplane equipment and

labor costs of adding flight data parameter (a)(88) at a higher

sampling rate and parameters (a)(89) through (a)(91) to a B-737

currently recording 22 flight data parameters would be about $49,000.

Finally, the FAA has adopted some preliminary industry estimates

that it would cost about $12,000 for the additional sensors and wiring

to retrofit flight data parameter (a)(88) at a higher sampling rate and

flight data parameters (a)(89) through (a)(91) in a B-737 FDR system

that now records 88 flight data parameters. In addition, the FAA has

estimated that this retrofit would involve about 160 labor hours. On

that basis, the FAA has estimated that these labor costs would be about

$12,000 per airplane.

Thus, the FAA has estimated that the per-airplane equipment and

labor costs of adding flight data parameter (a)(88) at a higher

sampling rate and parameters (a)(89) through (a)(91) to a B-737

currently recording 88 flight data parameters would be about $24,000.

Therefore, the FAA has estimated that retrofitting each B-737's

sensors and wiring would cost about $84,000 and take about 560 labor

hours for a B-737-200 or a B-737-400 without a FDAU; about $100,000 and

take about 760 labor hours for a B-737-300 and B-737-500 without a

FDAU; about $49,000 and take about 360 labor hours for an older B-737

airplane with a FDAU; and about $24,000 and take about 160 labor hours

for a newer B-737 airplane.

As a result, the FAA has estimated that the present value over the

next 18 months of the total sensor and wiring costs to retrofit all B-

737 FDR systems would be about $69 million.

Net Revenue Loss From Out-of-Service Time

The proposed rule would, effectively, require a B-737 to be taken

out of service due to the high number of labor hours for an FDR system

retrofit and the fact that only a few mechanics can work on the

airplane's FDR system simultaneously because of the limited physical

work space. An out-of-service airplane does not generate net revenue

and the longer the airplane is out of service, the greater the

airline's net revenue loss. However, if a retrofit were completed while

the B-737 is undergoing a regularly scheduled maintenance check, only

the net revenue lost from any additional out-of-service time could be

considered a cost of the proposed rule. For example, if an FDR system

retrofit would take 6 days and the B-737 is scheduled for a 3-day

maintenance check, only the lost net revenue from the additional 3 out-

of-service days would be a cost of the proposed rule. Thus, the lost

net revenue due to an FDR system retrofit of a given duration depends

upon whether the retrofit is performed during a regularly scheduled

maintenance check or whether the airplane must be taken out of service

solely to perform the retrofit.

The FAA has estimated that retrofitting a B-737 with a FDAU and

adding flight data parameters (a)(19) through (a)(22) would require 3

days out-of-service time for a B-737-200, an Advanced B-737-200, or a

B-737-400 while it would require 5 days out-of-service time for a B-

737-300 or a B-737-500. Based on a preliminary industry estimate, the

FAA has also estimated that, for B-737s that currently record at least

22 flight data parameters, adding proposed parameters (a)(89) through

(a)(91) and flight data parameter (a)(88) with the proposed increased

sampling rates, would require 4 days out-of-service time. The FAA has

further estimated that a B-737 adding flight data parameters ((a)(19)

through (a)(22) and (a)(88) through (a)(91)) would require 7 days out-

of-service time if retrofitting a B-737-200, a B-737-200 Advanced, or a

B-737-400. It would require 9 days out-of-service time if retrofitting

a B-737-300 or a B-737-500. If the retrofit were to be completed during

a 3-day maintenance check, the FAA has estimated that the incremental

out-of-service times due to the retrofit would be 2 days for a B-737

that has a FDAU, 4 days for a B-737-200 that does not have a FDAU, and

6 days for a B-737-300 or -500 that does not have a FDAU. If the

retrofit were to be completed during a 14-day or a 21-day major

maintenance check, the FAA has determined that the retrofit would

create no incremental out-of-service time.

The FAA has assumed that one 3-day maintenance check will occur

every 18 months for each B-737 and that a major 14-day or 21-day

maintenance check will occur every 5 years. As detailed in the Initial

Regulatory Evaluation, the FAA has developed a probability distribution

of the number of these B-737s by series and airplane age that would

have had a scheduled 3-day or 14-day maintenance check between the

estimated final rule effective date and the various compliance dates.

On that basis, the FAA estimated the various numbers of out-of-service

days for these airplanes.

In calculating the lost net revenue due to out-of-service time, the

FAA has taken the approach that an airplane is a piece of capital

equipment for which the average net revenue would equal the average

price of the airplane multiplied by the average annual risk-free

productive rate of return of capital. Using OMB's mandated 7 percent

average annual risk-free productive rate of return on capital, the FAA

has calculated that the average out-of-service lost net revenue per day

ranges from about $400 to about $10,500 per B-737, depending upon the

series and its average age. Thus, the FAA has estimated that the

present value of the total out-of-service lost net revenue due to

retrofitting the B-737 FDR systems would be about $25.2 million.

Total One-Time FDR System Retrofitting Costs

In summary, the FAA has estimated that the present value of the

total one-time compliance costs to retrofit all B-737 FDR systems by

the proposed compliance dates would be about $155 million.

Annual Costs Resulting From Retrofitting B-737 FDR Systems

The proposed rule also would generate annual compliance costs from

(1) The additional airplane weight from the retrofitted FDR system

equipment and wiring; and (2) additional maintenance costs annually to

validate the FDAU.

The FAA has estimated that the proposed rule would add about 40

pounds to a B-737 without a FDAU currently recording 18 flight data

parameters and about 10 pounds to a B-737 currently recording at least

22 flight data parameters. In calculating the estimated additional fuel

cost, the FAA has assumed a per-airplane average of 2,800 flight hours

per year, a price of $0.61 per gallon of aviation fuel, and 0.23

additional gallons consumed per additional pound per flight hour,

resulting in per-airplane annual costs of about $400 for a B-737 that

would add 40 pounds and about $100 for a B-737 that would add 10

pounds. On that basis, the FAA has estimated that the present value of

the increased fuel consumption over the next 20 years would be about

$3.6 million.

The FAA has further estimated that annual validation of a FDAU

would cost about $750. This incremental compliance cost would be

incurred only for B-737s retrofitted with FDAUs

[[Page 63151]]

because the operators of the other B-737s have elected to install this

equipment and, therefore, the validation cost would not be attributed

to this proposed rule. Based on the number of B-737s that would have

had FDAUs retrofitted and their expected retirement rates over the 20-

year time period, the FAA has calculated that the present value of this

annual FDAU validation over the next 20 years would be about $2.7

million.

Thus, the FAA has estimated that the present value of the annual

compliance costs over the next 20 years would be about $6.3 million.

Compliance Costs for Future Manufactured B-737

Installing additional proposed flight data parameters (a)(89)

through (a)(91) would also impose compliance costs upon all future

manufactured B-737s because, absent the proposed rule, those airplanes

would not have been manufactured to record those parameters. However,

newly manufactured B-737s are capable of recording all of the

additional flight data parameters with the exception of the standby

rudder on/off discrete (parameter (a)(91)) and the increase in

recording rates of all force information from once per second to twice

per second (parameter (a)(88)). As a result, the proposed rule would

impose production costs for additional wiring, sensors, and testing as

well as a cost to install an upgraded FDR system. There would be no

additional costs to upgrade the FDAU because the units currently

installed in production are capable of processing these additional

flight data parameters. The FAA has estimated that the additional

wiring and testing for production would cost about $25,000, a midstream

rudder force transducer would cost about $12,000, and the FDR upgrade

would cost about $1,900, for a total of $38,900 per future manufactured

B-737 beginning in the year 2001. On that basis, the FAA has calculated

that the present value of the additional costs for the approximately

2,144 U.S.-registered B-737s to be manufactured during the next 20

years would be about $40.4 million.

Potential Net Revenue Losses Currently Unquantifiable

The FAA's analysis of the net revenue losses for an out-of-service

airplane, although appropriate for the individual airplanes within an

airline's system, may not capture all of the potential lost revenue

when the entire system must comply within a short period of time. In

recognition of this potential analytical shortcoming, the FAA had

queried airlines concerning the potential system impacts. However, the

FAA has also realized that much of the information needed to perform a

more complete airline system analysis is proprietary and airlines are

extremely reluctant to provide it for fear of the data being

inappropriately or inadvertently disseminated to competitors.

Nevertheless, following discussions with the aviation industry, the FAA

believes that there are two areas of potential economic impact that may

need additional investigation, but for which the FAA does not have

adequate information.

The first area is that the FAA analysis has assumed that the time

to obtain the FAA approvals and the STC would not significantly affect

the airlines' abilities to meet the compliance dates. However, there is

a possibility that several of the airlines or repair stations would not

be able to obtain the requisite FAA approvals to be able to complete

these retrofits (particularly those for the proposed new flight data

parameters (a)(89) through (a)(91)) in the time between the

promulgation of the final rule and the August 18, 2000, or even the

August 20, 2001, compliance date. If, in fact, airline maintenance and

repair facilities would be overwhelmed with idle B-737s that cannot

return to service until they have been retrofitted, then the FAA may

have significantly underestimated the actual out-of-service times.

The second area is that the FAA does not have an appropriate model

to determine the impact on the number of available flights when, for 18

months, large numbers of airplanes would be taken out of service for

several days. For example, there is the possibility that air travel

service in certain markets would be disrupted, fares would increase,

load factors would increase and flights would become more crowded, some

passengers would choose not to fly, some passengers would be unable to

obtain flights at the times and dates they are accustomed to flying,

flight delays due to weather or mechanical problems would be longer

because there would be fewer airplanes available to fill in, etc.

In order to attempt to develop some estimates of the economic

impacts of these economic effects that have not been quantified, the

FAA specifically requests comments and supporting data on the magnitude

of these potential effects, including any presumptions applicable to an

individual operator or the industry as a whole.

Benefit-Cost Comparison of the Proposed Rule

In comparing the estimated benefits and costs, the FAA has

determined that if the proposed rule would prevent one accident during

the first 6 years after it would be promulgated, the benefits would be

greater than the costs. However, there is uncertainty about this

estimate because it depends on whether the future is adequately modeled

by past events and the amount of the currently unquantifiable net

revenue losses. As a result, the FAA has determined that it is in

general agreement with the NTSB recommendations that this information

is needed.

Alternatives to the Proposed Rule

The FAA has determined that its responsibilities under the

Regulatory Flexibility Act and the Unfunded Mandates Act require an

analysis of alternatives to the proposed rule for each purpose. Rather

than repeating the alternatives in each of those two sections, they are

listed in this separate section for reference.

The FAA has evaluated three alternatives to the proposed rule. In

formulating the alternatives, the FAA focused on its responsibility for

aviation safety and its particular obligation under 49 U.S.C. 44717 to

ensure the continuing airworthiness of airplanes. As a result, the

three evaluated alternatives to the proposed rule differ only with

respect to the dates of compliance--not on the content of the proposed

rule.

Alternative 1

Require all B-737s that currently have FDAUs (not just those B-737s

that had a FDAU installed prior to July 16, 1996) to record all of the

proposed flight data parameters by August 18, 2000, rather than by

August 20, 2001. This would shorten the compliance date for an

estimated 197 B-737s by one year. Alternative 1 would increase

compliance costs not because the actual retrofitting costs would change

but because the lost net revenue from out-of-service time would be

greater for some airplanes. A shorter compliance time increases the

likelihood that the retrofit would be done as a special project and not

as part of a regularly scheduled maintenance check. On that basis, the

FAA has estimated that Alternative 1 would increase first-year

compliance costs by $2.4 million above those costs associated with the

proposed rule. However, this alternative could be considerably more

expensive than the proposed rule, particularly if the idle airplane and

scheduling costs that the

[[Page 63152]]

FAA could not quantify are substantial. In that case, the shorter the

compliance period, the greater the idle airplane costs and scheduling

costs. As a result, in comparison to Alternative 1, the proposed rule

would offer considerably more relief to the airlines than is evidenced

by the quantified difference between them.

Alternative 1 would not significantly increase the estimated

quantitative benefits because the probability of one of these 197

airplanes having an accident whose probable cause would not have been

determined within a one-year timeframe is remote. As a result, the FAA

has determined that a commensurate increased level of benefits would

not match the increased cost of this Alternative 1.

Alternative 2

Delay the compliance date for all B-737s to August 20, 2001. This

would extend the compliance date by one year for about 292 airplanes.

The FAA has determined that Alternative 2 could reduce compliance costs

by about $7.3 million. This alternative would provide all B-737

operators with greater scheduling flexibility in determining when to

have the airplane retrofitted. A greater number of these operators

would be able to delay compliance until a regularly scheduled

maintenance check and, thereby, reduce the lost revenue from out-of-

service time. However, the FAA must also note that the converse to the

effect described under Alternative 1 would be a factor. Again, the

greater the unquantified costs, the greater the reduction in costs

associated with delaying compliance dates. As Alternative 2 would allow

greater flexibility than the proposed rule, the estimated compliance

cost reduction from Alternative 2 could be substantially

underestimated.

However, Alternative 2 could reduce the expected quantitative

benefits. There is a probability that one of these 292 airplanes could

have an accident or an incident whose cause would have been discovered

only if the additional flight data parameters had been recorded. In

light of the fact that the NTSB has recommended the August 18, 2000,

compliance date, the FAA has decided to meet the majority of the NTSB

recommendations and not propose a later compliance date for all B-737s.

Alternative 3

Delay the proposed compliance date for every B-737 until either its

next scheduled major (4 days or more) maintenance check or by August

18, 2004. Alternative 3 would give an operator its maximum retrofitting

scheduling flexibility. As the FAA has determined that nearly every B-

737 will have at least one scheduled major maintenance check within any

5-year time period, Alternative 3 would allow the operator to perform

the retrofit during a scheduled major maintenance check, which would

eliminate the additional out-of-service time and, hence, the potential

lost net revenue from compliance with the proposed rule. In addition,

Alternative 3 would spread the cost of the retrofits over a 5-year time

period. By doing so, the present value of the compliance cost from

Alternative 3 would be about $172.8 million, which would be about $32.6

million less than the compliance cost of the proposed rule. Further,

the FAA reiterates that the greater the unquantified costs, the greater

the reduction in costs associated with delaying compliance dates. As

Alternative 3 would allow greater flexibility than the proposed rule,

the estimated compliance cost reduction associated with Alternative 3

could be substantially underestimated.

Alternative 3 would reduce the expected quantitative benefits

because it would reduce the number of flight hours that the B-737 fleet

would have recorded the additional flight data parameters by about 6.6

million flight hours during those 4.5 years. Further, it would reduce

the cumulative probability that the additional recorded flight data

parameters from an accident or incident involving a B-737 could provide

information that would result in preventive regulatory or industry

action. Consequently, since the FAA agrees with the NTSB recommendation

that this information is important, the FAA has not proposed the

delayed compliance date presented in Alternative 3.

Thus, in comparison to the one higher cost alternative and the two

lower cost alternatives evaluated by the FAA, the FAA has determined

that the proposed rule would be the best method to address this safety

issue.

Regulatory Flexibility Determination

The Regulatory Flexibility Act of 1980 establishes ``as a principle

of regulatory issuance that agencies shall endeavor, consistent with

the objective of the rule and of applicable statutes, to fit regulatory

and informational requirements to the scale of the business,

organizations, and governmental jurisdictions subject to regulation.''

To achieve that principle, the Act requires agencies to solicit and

consider flexible regulatory proposals and to explain the rationale for

their actions. The Act covers a wide range of small entities, including

small businesses, not-for-profit organizations, and small governmental

jurisdictions.

Agencies must perform a review to determine whether a proposed or

final rule will have a significant economic impact on a substantial

number of small entities. If the agency determines that it will, the

agency must prepare a Regulatory Flexibility Analysis (RFA) as

described in the Act.

However, if an agency determines that a proposed or final rule is

not expected to have a significant economic impact on a substantial

number of small entities, section 605(b) of the Act provides that the

head of the agency may so certify, and an RFA is not required. The

certification must include a statement providing the factual basis for

this determination, and the reasoning should be clear.

Recently, the Office of Advocacy of the Small Business

Administration (SBA) published new guidance for Federal agencies in

responding to the requirements of the Regulatory Flexibility Act.

Application of that guidance to the proposed rule indicates that it

could have a significant economic impact on a substantial number of

small airlines. Accordingly, a complete initial regulatory flexibility

analysis was conducted for the proposed rule and is summarized as

follows:

Reasons Why the FAA is Considering the Proposed Rule

The flight data being recorded have not been sufficiently

comprehensive to determine the causes of several B-737 accidents and

incidents. As a result, the FAA and the aviation industry have been

unable to develop specific actions that may prevent similar future B-

737 accidents and incidents.

The Objectives and Legal Basis for the Proposed Rule

The objective of the proposed rule is to require the B-737 fleet to

record additional flight data parameters that may help determine the

cause(s) of a B-737 accident, and, thereby allow the development of

regulatory and industry actions that could prevent similar future

accidents. The legal basis for the proposed rule is 49 U.S.C. 44901 et

seq. As a matter of policy, the FAA must, as its highest priority (49

U.S.C. 40101 (d)), maintain and enhance safety and security in air

commerce.

[[Page 63153]]

All Relevant Federal Rules That May Duplicate, Overlap, or Conflict

With the Proposed Rule

The FAA is unaware of any federal rules that would duplicate,

overlap, or conflict with the proposed rule.

A Description and an Estimate of the Number of Small Entities to

Which the Proposal Would Apply

The proposed rule would apply to the operators of all U.S.-

registered B-737 airplanes operated under part 91, part 121, part 125,

or under part 129.

Nearly all of the 16 operators flying B-737s under part 91 (under

deviation authority from part 125) use the airplane as an ancillary

part of their primary business (for example, oil, automobile

manufacturing, etc.). As a result, these operators are distributed

across a spectrum of Standard Industrial Classification (SIC) codes,

and, as listed in the Initial Regulatory Evaluation, few are small

businesses.

The FAA has determined that the 3 non-U.S. operators of U.S.-

registered B-737s operating under part 129 are not small entities.

However, as seen shown in Table 2, based on a SBA definition that a

small airline has fewer than 1,500 employees, the FAA has determined

that 14 small airlines (assuming Accessair is a small airline and

noting that Metrojet is owned by USAirways) operating under part 121

would be affected by the proposed rule. The number of affected B-737s

reported in Table 3 is an FAA estimate of the number of those airplanes

by airline on August 2000.

Table 3.--Affected Airlines by Number of B-737s

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

Operating

Operator Number of B- Number of revenues (in $ Net profit (in

737 employees millions) $ millions)

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

Southwest....................................... 322 19,933 3,438.762 413.602

USAirways....................................... 205 43,100 8,556.000 965.182

United.......................................... 190 76,000 17,472.106 774.128

Continental..................................... 185 40,700 7,155.384 389.816

Delta........................................... 90 58,097 14,584.906 1,073.535

America West.................................... 70 10,013 1,962.480 104.350

Alaska.......................................... 50 10,137 1,553.158 106.162

Aloha........................................... 20 2,365 231.141 6.278

Frontier........................................ 19 440 174.713 (3.308)

Metrojet........................................ 15 .............. .............. ..............

Winair.......................................... 12 52 4.939 (1.150)

Vanguard........................................ 10 480 97.755 (7.460)

Airtran......................................... 9 600 .............. (6.985)

Eastwind........................................ 6 800 22.641 (8.684)

Pro Air......................................... 6 110 11.247 (18.849)

Accessair....................................... 3 .............. .............. ..............

Pace............................................ 3 20 4.914 0.256

Casino Express.................................. 2 102 15.692 (2.676)

Ryan Int........................................ 2 575 138.769 ..............

American........................................ 1 111,300 16,394.548 1,097.339

Lorair.......................................... 1 23 .............. ..............

Nations Air..................................... 1 154 6.724 0.299

North American.................................. 1 127 61.473 1.434

Sierra Pacific.................................. 1 35 6.650 0.631

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

Total..................................... .............. .............. .............. ..............

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

The Projected Reporting, Recordkeeping, and Other Compliance

Requirements of the Proposed Rule

Existing 14 CFR part 43, in part, already prescribes the content,

form, and disposition of maintenance, preventive maintenance,

rebuilding, and alteration records for any aircraft having a U.S.

airworthiness certificate or any foreign-registered aircraft used in

common carriage under part 121. There would be one-time paperwork costs

of about $9.15 million to obtain FAA parts approvals and STCs for the

modified FDR systems, but nearly all of these costs would be incurred

by large airlines and large repair stations and large parts

manufacturers. Finally, the proposed rule would necessitate minimal

additional annual maintenance, which would require minutes of annual

recordkeeping per airplane and negligible recordkeeping costs.

Regulatory Flexibility Cost Analysis

The compliance costs associated with the proposed rule are almost

completely specific to an individual airplane. There would be minimal

economies of scale in completing the FDR system retrofits. Thus, the

compliance cost for an individual B-737 is largely independent of the

size of the airline. The estimated present value of the compliance

costs per B-737 by series and FDR system capability is summarized in

Table 1. However, if the 1997 flight data recorder revisions and this

proposed rule are viewed as two parts of one rulemaking extended over

time, then the estimated per airplane cost would be increased by about

$45,000.

Affordability Analysis

As seen in Table 2, the FAA has obtained 1997 net profit data for

11 of the 14 affected small airlines, although the FAA lacks detailed

financial data for most of them. Of those 11 small airlines, 7 reported

losses. Of the remaining 4 small airlines, the compliance costs would

have turned one airline's positive profit into a loss, cut another's

profit in half, and reduced the others' profits by 16 percent and by 7

percent. When coupled with the costs to comply with the 1997 flight

data recorder revisions, these profits would have been further reduced

and the losses would have been further increased. Consequently, the FAA

has concluded that some of these small airlines may face financial

difficulties in offsetting these compliance costs. The FAA solicits

comments on the affordability of the

[[Page 63154]]

proposed rule for small airlines and requests that all comments be

accompanied with clear supporting data.

Disproportionality Analysis

As noted earlier in this regulatory flexibility cost analysis, the

incremental compliance costs for a B-737 operated by a large airline

and those costs for an identical B-737 operated by a small airline

would be nearly identical. However, to the extent that financing

charges tend to be larger for a small airline than for a large airline

with a better-established credit line, the financing costs for the

retrofit would be disproportionally larger for a small airline than for

a large airline. The FAA does not have information concerning this

potential impact. Nevertheless, the significant disproportionality that

may occur would depend upon the percentage of an airline's fleet that

is composed of B-737s. The higher the percentage of B-737s, the greater

the impact of this proposed rule on that airline. In reviewing the

composition of these various fleets, the FAA has determined that there

is not a significant difference, on average, between the group of large

airlines and the group of small airlines--although there are certainly

differences among individual airlines. As a result, small airlines

operating B-737s would not be disadvantaged, as a group, relative to

the group of large airlines operating B-737s.

Competitiveness Analysis

The proposed rule would impose significant first-year costs on all

operators of B-737s and, as a consequence, may affect the relative

position of these airlines in their markets. As the proposed rule would

impose no costs on other small operators using McDonnell Douglas or

Airbus airplanes, the FAA has determined that there could be a

significantly adverse competitiveness effect on certain small (and

large) airlines that operate B-737s. The principle beneficiaries would

be other small and large airlines that do not operate B-737s.

Business Closure Analysis

The FAA is unable to determine with certainty whether any of these

small airlines would close their operations. Many very small operations

(1 to 4 airplanes) operate very close to the margin, as evidenced by

their constant exit from and entry into various markets. As noted, most

of the small airlines reported losses, but, in the absence of

sufficiently detailed financial data, the FAA cannot determine which,

if any, of these small airlines would close due to the proposed rule.

Description of Alternatives

The three alternatives evaluated by the FAA are discussed in an

earlier preamble section. As described, delaying the compliance dates

would provide some relief to the affected small and large airlines.

However, the proposed rule would still provide a competitive advantage

to airlines operating airplanes other than B-737s over small and large

airlines that operate B-737s.

Special Considerations

Although the proposed rule would have a significant economic impact

on small airlines, the FAA has not exempted them from the proposed

rule. The principal reason for not exempting them is that B-737

accidents and incidents whose causes have not been determined are not

related to the size of the operator; both large and small airlines have

been affected. For example, incidents have occurred to B-737s operated

by small airlines. In particular, the 1996 Eastwind B-737 incident is

very similar to the United and USAir B-737 accidents. The Eastwind

airplane recorded only 11 flight data parameters and, consequently,

that incident's cause has not been fully determined. Thus, the FAA has

determined that special considerations for small airlines would not be

appropriate.

Conclusion

The FAA has determined that there are no viable alternatives to the

proposed rule for small airlines. Consequently, the FAA has concluded

that exempting B-737s or delaying compliance dates for B-737s operated

by small airlines would be an inappropriate action and inconsistent

with the FAA mandate to ensure aviation safety. The FAA requests

comments on this initial regulatory flexibility analysis and requests

commenters to supply supporting data for the comments.

International Trade Impact Assessment

Consistent with the Administration's belief in the general

superiority, desirability, and efficacy of free trade, it is the policy

of the Administrator to remove or diminish, to the extent feasible,

barriers to international trade, including both barriers affecting the

export of American goods and services to foreign countries and those

affecting the import of foreign goods and services into the United

States.

In accordance with that policy, the FAA is committed to develop as

much as possible its aviation standards and practices in harmony with

its trading partners. Significant cost savings can result from this

harmonization, both to American companies doing business in foreign

markets, and foreign companies doing business in the United States.

This proposed rule would have a minimal impact on international

trade. Although it would increase the cost of manufacturing a future B-

737 by about $39,000, the FAA does not believe that this increase would

have a significantly negative effect on Boeing's future domestic or

international markets for the B-737.

Unfunded Mandates Assessment

Title II of the Unfunded Mandates Reform Act of 1995 (the Act),

enacted as Public Law 104-4 on March 22, 1995, requires each Federal

agency, to the extent permitted by law, to prepare a written assessment

of the effects of any Federal mandate in a proposed or final agency

rule that may result in the expenditure by State, local, and tribal

governments, in the aggregate, or by the private sector, of $100

million or more (adjusted annually for inflation) in any one year.

Section 204(a) of the Act, 2 U.S.C. 1534(a), requires the Federal

agency to develop an effective process to permit timely input by

elected officers (or their designees) of State, local, and tribal

governments on a proposed ``significant intergovernmental mandate.'' A

``significant intergovernmental mandate'' under the Act is any

provision in a Federal agency regulation that will impose an

enforceable duty upon state, local, and tribal governments, in the

aggregate, of $100 million (adjusted annually for inflation) in any one

year. Section 203 of the Act, 2 U.S.C. 1533, which supplements section

204(a), provides that before establishing any regulatory requirements

that might significantly or uniquely affect small governments, the

agency shall have developed a plan that, among other things, provides

for notice to potentially affected small governments, if any, and for a

meaningful and timely opportunity to provide input in the development

of regulatory proposals.

Under 49 U.S.C. 40101(d)(1), the FAA Administrator is required to

consider the following matter, among others, as being in the public

interest: maintaining and enhancing safety and security as the highest

priorities in air commerce. Additionally it is the Administrator's

statutory duty to perform the responsibilities ``in a way that best

tends to reduce or eliminate the

[[Page 63155]]

possibility or recurrence of accidents in air transportation.'' (See 49

U.S.C. 44701(c).)

The FAA has determined that this proposed rule would not contain a

significant intergovernmental mandate as defined by the Act because the

FAA has no knowledge of any State, local, or tribal government

operating a B-737.

However, the FAA has determined that this proposed rule would

contain a significant private sector mandate as defined by the Act

because the compliance costs over the first 18 months would be about

$243 million for the private sector. Thus, the FAA has evaluated the

three previously described alternatives in order to determine if the

burden could be reduced in a manner consistent with the FAA's mandate

to provide aviation safety. Of the three alternatives, only Alternative

3 (delaying compliance until a scheduled major maintenance check) would

lower the compliance costs below $100 million for every year.

Nevertheless, for the reasons discussed in that earlier section, the

FAA has determined that Alternative 3 would not attain the same level

of B-737 risk reduction at a lower cost than the proposed rule.

Federalism Implications

The regulations proposed herein would not have a substantial direct

effect 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 12612, it is determined that this

proposal would not have sufficient federalism implications to warrant

the preparation of a federalism assessment.

Environmental Analysis

FAA Order 1050.1D defines FAA actions that may be categorically

excluded from preparation of a National Environmental Policy Act (NEPA)

environmental assessment or environmental impact statement. In

accordance with FAA Order 1050.1D, appendix 4, paragraph 4(j), this

rulemaking action qualifies for a categorical exclusion.

Energy Impact

The energy impact of the proposed rule has been assessed in

accordance with the Energy Policy and Conservation Act (EPCA) and

Public Law 94-163, as amended (42 U.S.C. 6362). It has been determined

that it is not a major regulatory action under the provisions of EPCA.

Comment Period

Comments on this proposed rule must be received by the agency

within 30 days of the date of publication of this document. The FAA

understands that this does not allow affected operators and other

interested parties much time to gather and submit the information

requested by the FAA. However, the agency has determined that it is

more important to give affected operators the maximum available time to

comply with the new requirements once a final rule is adopted. The FAA

generally agrees with the NTSB that B-737 airplanes be retrofitted to

record the additional flight data by August 18, 2000. The FAA has

determined that the short time available requires that the comment

period on this rule be kept to a minimum. The FAA also notes that there

has been considerable publicity concerning the NTSB recommendations,

and that questions addressed to the FAA indicate that the recommended

actions and the issues surrounding them are well known.

For these reasons, the FAA strongly encourages commenters to submit

their comments as soon as possible. Late-filed comments will be

considered to the extent that they do not unnecessarily delay the

promulgation of a final rule.

List of Subjects

14 CFR Part 91

Aviation safety, Reporting and recordkeeping requirements.

14 CFR Part 121

Air carriers, Aviation safety, Air transportation, Reporting and

recordkeeping requirements.

14 CFR Part 125

Aviation safety, Reporting and recordkeeping requirements.

The Proposed Amendment

In consideration of the foregoing, the Federal Aviation

Administration proposes to amend parts 91, 121, and 125 of Title 14,

Code of Federal Regulations as follows:

PART 91--GENERAL OPERATING AND FLIGHT RULES

1. The authority citation for part 91 continues to read as follows:

Authority: 49 U.S.C. 106(g), 1155, 40103, 40113, 40120, 44101,

44701, 44705, 44709, 44711, 44712, 44715, 44716, 44717, 44722,

44901, 46306, 46315, 46316, 46504, 46506-46507, 47122, 47508, 47528-

47531, articles 12 and 29 of the Convention on International Civil

Aviation (61 stat. 1180).

2. Section 91.609 is amended by adding a new paragraph (h) to read

as follows:

Sec. 91.609 Flight recorders and cockpit voice recorders.

* * * * *

(h) An aircraft operated under this part under deviation authority

from part 125 of this chapter must comply with all of the applicable

flight data recorder requirements of part 125 applicable to the

aircraft, notwithstanding such deviation authority.

PART 121--OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL

OPERATIONS

3. The authority citation for part 121 continues to read as

follows:

Authority: 49 U.S.C. 106(g), 40113, 40119, 44101, 44701-44702,

44705, 44709-44711, 44713, 44716-44717, 44722, 44901, 44903-44904,

44912, 46105.

4. Section 121.344 is amended in paragraph (a) by removing the word

``and'' after paragraph (a)(87); by removing the period after paragraph

(a)(88) and adding a semicolon in its place; and by adding new

paragraphs (a) (89), (90), and (91), (d)(3), (e)(3) and (m); and by

revising paragraphs (b) introductory text, (c) introductory text, and

(f) to read as follows:

Sec. 121.344 Digital flight data recorders for transport category

airplanes.

(a) * * *

(89) Yaw damper status;

(90) Yaw damper command; and

(91) Standby rudder status.

(b) Except for Boeing 737 model airplanes, for all turbine-engine

powered transport category airplanes manufactured on or before October

11, 1991, by August 20, 2001--

* * * * *

(c) Except for all Boeing 737 model airplanes, for all turbine-

engine powered transport category airplanes manufactured on or before

October 11, 1991--

* * * * *

(d) * * *

(3) In addition to the requirements of paragraphs (d)(1) and (d)(2)

of this section, all Boeing 737 model airplanes also must comply with

the requirements of paragraph (m)(1) or (m)(2) of this section, as

applicable.

* * * * *

(e) * * *

(3) In addition to the requirements of paragraphs (e)(1) and (e)(2)

of this section, all Boeing 737 model airplanes, also must comply with

the requirements of paragraph (m)(1) of this section.

[[Page 63156]]

(f) For all turbine-engine powered transport category airplanes

manufactured after August 19, 2002--

(1) The parameters listed in paragraphs (a)(1) through (a)(88) of

this section must be recorded within the ranges, accuracies,

resolutions and recording intervals specified in appendix M to this

part.

(2) In addition to the requirements of paragraph (f)(1) of this

section, all Boeing 737 model airplanes, also must also comply with the

requirements of paragraph (m)(1) of this section.

* * * * *

(m) In addition to all other applicable requirements of this

section, all Boeing 737 model airplanes must record the parameters

listed in paragraphs (a)(1) through (a)(22) and (a)(88) through (a)(91)

of this section, within the ranges, accuracies, resolutions, and

recording intervals specified in appendix M to this part, in accordance

with the following schedule:

(1) All Boeing 737 model airplanes equipped with a flight data

acquisition unit of any type as of July 16, 1996, or manufactured after

July 16, 1996, must comply by August 18, 2000.

(2) All Boeing 737 model airplanes not equipped with a flight data

acquisition unit of any type as of July 16, 1996, must comply by August

20, 2001.

5. Appendix M to part 121 is amended by revising item 88 and adding

items 89 through 91 to read as follows:

Appendix M to Part 121--Airplane Flight Recorder Specification--

Continued

* * * * * * *

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

Accuracy (sensor Seconds per sampling

Parameter Range input) interval Resolution Remarks

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

88. All cockpit flight control Full range............ 5%........ 1.................... 0.2% of full range... For fly-by-wire

input forces (control wheel, Control wheel 70 lbs. systems, where

Control column 85 lbs. surface position is

Rudder pedal 70 lbs. displacement of the

control input device

only, it is not

necessary to record

this parameter. For

airplanes that have

a flight control

break away

capability that

allows either pilot

to operate the

control

independently,

record both control

force inputs. The

control force inputs

may be sampled

alternately once per

2 seconds to produce

the sampling

interval of 1.

89. Yaw damper status.............. Discrete (on/off)..... ...................... 0.5.................. ..................... .....................

90. Yaw damper command............. Full range............ As installed.......... 0.5.................. 1% of full range..... .....................

91. Standby rudder status.......... Discrete (on/off)..... ...................... 0.5.................. ..................... .....................

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

\14\ For all Boeing 737 model airplanes, the seconds per sampling interval is 0.5 per control input; remarks do not apply.

PART 125--CERTIFICATION AND OPERATIONS: AIRPLANES HAVING A SEATING

CAPACITY OF 20 OR MORE PASSENGER OR A MAXIMUM PAYLOAD CAPACITY OF

6,000 POUNDS OR MORE

6. The authority citation for part 125 continues to read as

follows:

Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44705, 44710-

44711, 44713, 44716-44717, 44722.

7. Section 125.3 is amended by adding a new paragraph (d) to read

as follows:

Sec. 125.3 Deviation authority.

* * * * *

(d) No deviation authority from the flight data recorder

requirements of this part will be granted. Any previously issued

deviation from the flight data recorder requirements of this part is no

longer valid.

8. Section 125.226 is amended in paragraph (a) by removing the word

``and'' after paragraph (a)(87); by removing the period after paragraph

(a)(88) and adding a semicolon in its place; by adding new paragraphs

(a)(89), (90), and (91), (d)(3), (e)(3), and (m); and by revising

paragraphs (b) introductory text, (c) introductory text, and (f) to

read as follows:

Sec. 125.226 Digital flight data recorders.

(a) * * *

(89) Yaw damper status;

(90) Yaw damper command; and

(91) Standby rudder status.

(b) Except for Boeing 737 model airplanes, for all turbine-engine

powered transport category airplanes manufactured on or before October

11, 1991, by August 20, 2001--

(c) Except for all Boeing 737 model airplanes, for all turbine-

engine powered transport category airplanes

[[Page 63157]]

manufactured on or before October 11, 1991--

(d) * * *

(3) In addition to the requirements of paragraphs (d)(1) and (d)(2)

of this section, all Boeing 737 model airplanes also must comply with

the requirements of paragraph (m)(1) or (m)(2) of this section, as

applicable.

(e) * * *

(3) In addition to the requirements of paragraphs (e)(1) and (e)(2)

of this section, all Boeing 737 model airplanes, also must comply with

the requirements of paragraph (m)(1) of this section.

(f) For all turbine-engine powered transport category airplanes

manufactured after August 19, 2002--

(1) The parameters listed in paragraphs (a)(1) through (a)(88) of

this section must be recorded within the ranges, accuracies,

resolutions and recording intervals specified in appendix E to this

part.

(2) In addition to the requirements of paragraph (f)(1) of this

section, all Boeing 737 model airplanes must also comply with the

requirements of paragraph (m)(1) of this section.

* * * * *

(m) In addition to all other applicable requirements of this

section, all Boeing 737 model airplanes must record the parameters

listed in paragraphs (a)(1) through (a)(22) and (a)(88) through (a)(91)

of this section, within the ranges, accuracies, resolutions, and

recording intervals specified in appendix E to this part, in accordance

with the following schedule:

(1) All Boeing 737 model airplanes equipped with a flight data

acquisition unit of any type as of July 16, 1996, or manufactured after

July 16, 1996, must comply by August 18, 2000.

(2) All Boeing 737 model airplanes not equipped with a flight data

acquisition unit of any type as of July 16, 1996, must comply by August

20, 2001.

9. Appendix E to part 125 is amended by revising item 88, and

adding items 89 through 91 to read as follows:

Appendix E to Part 125--Airplane Flight Recorder Specification--

Continued

* * * * * * *

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

Accuracy (sensor Seconds per sampling

Parameter Range input) interval Resolution Remarks

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

88. All cockpit flight control Full range............ 5%........ 1.................... 0.2% of full range... For fly-by-wire

input forces (control wheel, Control wheel 14. minus>70 lbs. systems, where

Control column 85 lbs. surface position is

Rudder pedal 165 lbs. displacement of the

control input device

only, it is not

necessary to record

this parameter. For

airplanes that have

a flight control

break away

capability that

allows either pilot

to operate the

control

independently,

record both control

force inputs. The

control force inputs

may be sampled

alternately once per

2 seconds to produce

the sampling

interval of 1.

89. Yaw damper status.............. Discrete (on/off)..... ...................... 0.5.................. ..................... .....................

90. Yaw damper command............. Full range............ As installed.......... 0.5.................. 1% of full range..... .....................

91. Standby rudder status.......... Discrete (on/off)..... ...................... 0.5.................. ..................... .....................

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

\14\ For all Boeing 737 model airplanes, the seconds per sampling interval is 0.5 per control input; remarks do not apply.

Issued in Washington, DC, on November 9, 1999.

Ronald T. Wojnar,

Acting Director, Aircraft Certification Service.

[FR Doc. 99-29758 Filed 11-17-99; 8:45 am]

BILLING CODE 4910-13-P