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Proposed Rule

Petition for Rulemaking; Summary of Petition Received

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Federal Aviation Administration (FAA), DOT.


Notice of petition for rulemaking received; request for comments.


Although not required under part 11 of Title 14, Code of Federal Regulations (14 CFR), this document contains a summary of a petition for rulemaking to amend certain requirements of 14 CFR. While the FAA considers the best course of action on this matter, we believe the public should be made aware of this petition for rulemaking, and we specifically request comments from other aircraft manufacturers who may be experiencing problems similar to those encountered by the petitioner, Airbus. Neither publication of this document nor the inclusion or omission of information in the summary is intended to affect the legal status of any petition or its final disposition. The facts presented in this summary are as presented by the petitioner.


Comments on petitions received must identify the petition docket number involved and must be received on or before May 22, 2002.


Send comments on any petition to the Docket Management System, U.S. Department of Transportation, Room Plaza 401, 400 Seventh Street, SW., Washington, DC 20590-0001. You must identify the docket number FAA-2002-11705 at the beginning of your comments. If you wish to receive confirmation that FAA received your comments, include a self-addressed, stamped postcard.

You may also submit comments through the Internet to You may review the public docket containing the petition, any comments received, and any final disposition in person in the Dockets Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Dockets Office (telephone 1-800-647-5527) is on the plaza level of the NASSIF Building at the Department of Transportation at the above address. Also, you may review public dockets on the Internet at

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Forest Rawls (202) 267-8033, Office of Rulemaking (ARM-1), Federal Aviation Administration, 800 Independence Avenue, SW., Washington, DC 20591.

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Issued in Washington, DC on April 8, 2002.

Donald P. Byrne,

Assistant Chief Counsel for Regulations.

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Petition for Rulemaking

Docket No.: FAA-2002-11705.

Petitioner: Airbus.

Section of 14 CFR Affected: Appendix M to part 121 and Appendix E to part 125 of 14 CFR

Description of Relief Sought: The rulemaking implemented by FAA in August of 1997 (62 FR 38362) substantially improved the requirements for recording of up to 88 parameters of flight data for diagnostic use in the event of an accident or serious incident. Most of the improvement in the recording capability did not directly apply to Airbus aircraft, however, because almost all of the additional parameters required by FAA had long been incorporated into the standard Airbus product specification. However, in a few cases, the very detailed specifications adopted in the FAA rule differed slightly from the recording parameters that had been implemented in Airbus aircraft. In that rulemaking, it was clearly stated that FAA had tailored that rule to avoid major equipment redesign or retrofits. The new requirements are to be met in stages, with the first 34 parameters being treated initially (at the next heavy maintenance check after August 18, 1999, but no later than August 20, 2001), followed by parameters 35 through 57 (for aircraft manufactured after August 18, 2000, upon delivery), and finally parameters 58 through 88 (for aircraft manufactured after August 19, 2002, upon delivery).

On August 24, 1999 (64 FR 46117), FAA amended this digital flight data recorder (DFDR) resolution recording requirements for several parameters for Airbus airplanes. The amendments addressed only the first 34 parameters. Similarly, on August 24, 2000, the FAA revised the DFDR regulations to accommodate several technical changes related to parameters 35 through 57 for Airbus.

Airbus has now completed its audit of compliance requirements for Parameters 58 through 88, and finds three specific technical issues of compliance for which it seeks rule changes. Specifically, Airbus seeks minor technical changes as specified herein to the recording requirements for parameter 83 (cockpit trim control input position—roll), parameter 84 (cockpit trim control input position—yaw), and parameter 88 (cockpit flight control input forces—rudder).

Airbus notes that the FAA, in adopting the new DFDR recording resolution requirements did not intend to require equipment redesign or retrofit. The cockpit trim position recording specification changes that are requested would be implemented in order to comply with that aim. These sensors have been installed on Airbus aircraft for many years, and it adds no safety or analytic benefit that Airbus can identify to replace these sensors with ones that are literally compliant with the regulatory specifications. The resolution deviations sought are small, and fully consistent with the smallest increment employed in the parameters employed for actual control of the respective flight control surfaces.

With regard to rudder pedal forces, the Airbus implementation requires a sensor that sums the rudder pedal forces from the cockpit pedals, these having no independent breakaway capability. Therefore, though the force is accurately measured, the actual force applied at each pedal varies somewhat with pedal ergonomics, adjusted to account for size differences from person to person, and also with actual pedal position. However, this shortfall in accuracy does not prohibit detailed and continuous high-resolution determination of the force that is applied to the rudder pedals so as to permit diagnosis of the source of movement of the pedals themselves (parameter 14) and the flight control surface (parameter 17). In fact, the inaccuracy due to pedal position can be corrected based on the measurement of parameter 14, leaving only the inaccuracy resulting from ergonomic adjustment. If the ergonomic adjustment is known (based on post-accident aircraft examination, for example), it, too, can be corrected.

Specifically, changes are sought to the recording requirements for the following parameters as contained in Appendix M to part 121 and Appendix E to part 125 of 14 CFR:

For A310 and A300-6 series aircraft. Parameter 83, cockpit trim control input position-roll: Required to be resolved to 0.028 degrees (0.2% of operational range of ±7 degrees) but is implemented with Start Printed Page 19535a resolution of 0.096 degrees. Note, however, that this resolution is nearly identical to the smallest increment used in deflection of the roll control surfaces for each model, which is 0.092 degrees in the A310 aircraft and 0.091 degrees in the A300-600 aircraft. Thus, achieving the additional resolution would provide no substantive benefit.

For A318/319/320/321 series aircraft. Parameter 84, cockpit trim control input position-yaw: Required to be resolved to 0.08 degrees (0.2% of operational range of ±20 degrees but is implemented with a resolution of 0.088 degrees. Note, however, that this resolution surpasses the smallest increment used to deflect the yaw control surfaces for each model, which is 0.112 degrees for the A320 family.

For A310, A300-600, A318/319/320/321, A330 and A340 (except A340-500 and -600 models) series aircraft. Parameter 88, cockpit flight control input forces-rudder pedal: Required to have accuracy of 5% but is implemented with an accuracy of 2.5%-15%, depending upon the position of the pedal adjustment for ergonomic reasons, and the exact position of the pedals at the time the force is applied. These inaccuracies arise from the complex mechanical arrangement necessary to transmit pedal forces to the rudder control cables. There are two principal sources of this inaccuracy, and it is possible that one or both of them may be eliminated in post-accident analysis. However, for the purpose of compliance determination, Airbus elects to assume a worst case situation where neither inaccuracy can be eliminated, and therefore seeks this rule change.

The first uncertainty and largest source of inaccuracy is that associated with ergonomic adjustment of the pedal position to accommodate pilots of differing heights. If the pedal position selected can in fact be determined (for example by examination of the aircraft after an accident or incident), then this inaccuracy can be eliminated. The second uncertainty comes from the fact that, for a given pedal force, the recorded force varies somewhat depending on the position of the rudder pedals when the force is applied. If it is possible (and it should be so) to use the recorded rudder pedal position to calculate the position inaccuracy in post accident/incident review, then this inaccuracy can also be eliminated. Note that the resolution of this parameter as recorded complies with the required 0.2% of full range, and therefore the functionality of the recorded parameter is not adversely affected.

In the appendix to its petition, Airbus submits specific proposed regulatory language. In Appendix M to part 121 and Appendix E to part 125, Airbus requests that footnotes be added to the recording requirements for parameters 83, 84, and 88. For parameter 83, Airbus recommends the following footnote: For A310 and A300-600 airplanes, resolution = 0.69% (0.096 degrees). For parameter 84, Airbus requests the following footnote: For A318/319/320/321 series aircraft, resolution = 0.22% (0.088 degrees). For parameter 88, Airbus requests the following footnote: For A310, A300-600, A318/319/320/321, A330 and A340 (except A340-500 and -600 models) series aircraft, accuracy = 15%.

According to Airbus, the changes requested are minor and technical in nature, and none would significantly affect the ability of accident investigators to perform their tasks. Additionally, Airbus contends that the changes would neither adversely affect the safety of the aircraft, hinder the investigation of accidents or incidents, nor compromise the intent of the DFDR rules. Airbus states the changes only would account for the differences in Airbus DFDR equipment when compared to the precise regulatory requirements.

Airbus also asserts that a large cost to US operators would obviously be involved in redesigning and fitting new equipment to effect literal compliance with the recording resolution requirements of the current regulations. In addition, with the delivery of new aircraft whose implemented DFDR recording equipment differs from that installed on existing aircraft, a second set of spares and additional record keeping requirements would need to be instituted, further increasing costs on an ongoing basis. These added costs would not be balanced by an gain in safety or investigative capability deriving from such changes. It is, therefore, in the public interest to make the requested regulatory modifications so as to obviate an unnecessary and unproductive expenditure by US airlines, according to Airbus.

Airbus requests that the FAA issue a final rule without notice and prior public comment.

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[FR Doc. 02-9129 Filed 4-19-02; 8:45 am]