Airworthiness standards: Crash resistant fuel systems,

[Federal Register: December 30, 1999 (Volume 64, Number 250)]

[Proposed Rules]

[Page 73437]

From the Federal Register Online via GPO Access []


Proposed Rules Federal Register

This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules.

[[Page 73437]]


Federal Aviation Administration

14 CFR Part 23

[Docket No. 24494; Notice No. 85-7A]

RIN 2120-AA57

Airworthiness Standards; Crash Resistant Fuel Systems

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM); withdrawal.

SUMMARY: The FAA is withdrawing a previously published Notice of Proposed Rulemaking (NPRM) that proposed to amend the airworthiness standards for normal, utility, acrobatic, and commuter category airplanes. That notice proposed upgrades in the requirements for fuel system components that would have improved crash resistance of these systems by limiting fuel spillage near ignition sources and thus provide additional time for survivors of the impact to evacuate the airplane. As a result of the comments received, the FAA completed a revised economic evaluation of these safety recommendations and has concluded that the costs of the proposed change are not justified by the potential benefits. Accordingly, the FAA is planning no additional proposals on this issue.

FOR FURTHER INFORMATION CONTACT: Scott Sedgwick, Standards Office (ACE- 110), Small Airplane Directorate, Aircraft Certification Service, Federal Aviation Administration, 601 East 12th Street, Kansas City, Missouri 64106; telephone (816) 426-6941.



On February 28, 1990, the FAA published Notice of Proposed Rulemaking No. 85-7A (55 FR 7280) that proposed an amendment to 14 CFR part 23 and invited public comment. The comment period closed on June 28, 1990. Seventeen commenters responded to the notice.

Several commenters disagreed with the economic evaluation contained in the NPRM and believed that either the benefits had been overestimated, costs had been underestimated, or both. The FAA agrees, and after completing an extensive economic evaluation of these safety recommendations has determined that the costs of the proposed change are not justified by the potential benefits.

Some commenters believed that the proposed Sec. 23.993(f) probably would result in the incorporation of some sort of self-closing device in fuel lines and that the reliability of such devices should be addressed. The FAA agrees, and the referenced economic evaluation also includes the effects of uncommanded operation of such devices.

Other Comments

There were both positive and negative overall comments on the NPRM proposals. However, as the proposals are not economically feasible at this time, every comment will not be addressed in specific detail. The most pertinent comments are summarized as follows.

Several commenters suggested definitions of a ``survivable'' crash along with specific improvements/changes to the proposed regulations. The FAA agrees that a definition of a survivable crash would be necessary to proceed with the proposal. Because the NPRM is being withdrawn, the FAA has noted these definitions, along with the comments specific to the actual wording of the proposed regulations, for possible future reference.

Several commenters disagreed with either mandating the use of flexible bladder tanks, certain aspects of their use, or both. The FAA agrees it is more appropriate to specify an objective test for fuel tanks (leaving the details of design and construction to the designer) than to mandate the use of flexible bladder tanks. Because this NPRM is being withdrawn, the FAA has noted these comments for possible future reference.

There were both positive and negative comments regarding the applicability of the proposal to previously type-certificated, newly manufactured (in addition to newly type-certificated) airplanes. These will not be addressed in specific detail because the NPRM is being withdrawn. However, one commenter did suggest making the standards applicable to newly manufactured airplanes on an individual model basis rather than on an overall basis as proposed. The commenter refers to a report by the FAA, DOT/FAA/CT-86/24, Study of General Aviation Fire Accidents (1974-1983), which the commenter believes shows that some airplane types are more prone to post-crash fires than others. The FAA agrees with the observation that some airplane types are more prone to post-crash fires than others. However, the FAA does not selectively apply airworthiness standards (such as these proposed rules) to specific airplane models. These standards define a minimum level of safety that applies to all airplanes certificated in a given category.

Additionally, two commenters objected that the proposals did not adhere to the recommendations made by the GASP II committee. The FAA's rationale for not following those recommendations is contained in the preamble to the NPRM and remains unchanged.

Several comments were beyond the scope of the NPRM and, though some were commendable, they will not be addressed further.

Withdrawal of Proposed Rule

In consideration of those comments to Notice No. 85-7A regarding the cost-benefit analysis, the Federal Aviation Administration has decided to withdraw Notice No. 85-7A for further internal study. Accordingly, Notice No. 85-7A, published on February 28, 1990 (55 FR 7280), is withdrawn.

Issued in Washington, D.C. on December 21, 1999. Ronald T. Wojnar, Acting Director, Aircraft Certification Service.

[FR Doc. 99-33801Filed12-29-99; 8:45 am]