[Federal Register Volume 64, Number 250 (Thursday, December 30, 1999)]
[Proposed Rules]
[Page 73437]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-33801]

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.


Federal Register / Vol. 64, No. 250 / Thursday, December 30, 1999 / 
Proposed 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 
    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. 99-33801 Filed 12-29-99; 8:45 am]