[Federal Register Volume 61, Number 19 (Monday, January 29, 1996)]
[Proposed Rules]
[Pages 2730-2731]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-1570]



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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.

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Federal Register / Vol. 61, No. 19 / Monday, January 29, 1996 / 
Proposed Rules

[[Page 2730]]


DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-162-AD]


Airworthiness Directives; Boeing Model 747-200, -300, and -400 
Series Airplanes Equipped with General Electric Model CF6-80C2 PMC and 
CF6-80C2 FADEC Engines, and Pratt & Whitney Model PW4000 Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain Boeing Model 747-
200, -300, and -400 series airplanes, that currently requires 
inspection of each fuel feed line of the outboard engine in the engine 
strut to determine if interference with an adjacent pneumatic duct 
clamp has caused damage, and repair or replacement of the fuel feed 
tube, if necessary. That AD also currently requires inspection and 
replacement of the adjacent pneumatic duct clamp with a non-rotating 
type clamp, if necessary. This action would require modification of the 
upper gap area of the strut of the number 1 and 4 engines. This 
proposal is prompted by a report of fuel leakage in the strut of the 
number 4 engine due to a high profile clamp that chafed the fuel line. 
The actions specified by the proposed AD are intended to prevent 
chafing of the fuel line in the strut of the number 1 and 4 engines, 
which could result in rupture of the fuel line and subsequent in-flight 
engine fire.

DATES: Comments must be received by March 25, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-162-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Kenneth W. Frey, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington; 
telephone (206) 227-2673; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall ientify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 95-NM-162-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules 
Docket No. 95-NM-162-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On April 5, 1991, the FAA issued AD 91-05-19, amendment 39-6918 (56 
FR 8705, March 1, 1991), applicable to certain Boeing Model 747-200, -
300, -400 series airplanes equipped with General Electric Model CF6-
80C2 PMC and CF6-80C2 FADEC engines, and Pratt & Whitney Model PW4000 
engines. That AD currently requires inspection of each fuel feed line 
of the outboard engine in the engine strut to determine if interference 
with an adjacent pneumatic duct clamp has caused damage to the fuel 
feed tube; and repair or replacement of the fuel feed tube, if 
necessary. That AD also currently requires inspection and replacement 
of the adjacent pneumatic duct clamp with a non-rotating type clamp if 
a non-rotating clamp is not already installed. That action was prompted 
by report of a fuel leak in the number 4 engine strut due to a 
punctured fuel feed line that had chafed as a result of contact with a 
clamp. The requirements of that AD are intended to prevent an engine 
fire.
    Since the issuance of that AD, the FAA has received a report of 
fuel leakage in the strut of the number 4 engine. Investigation 
revealed that the fuel leakage was caused by a punctured fuel feed 
tube; the fuel tube was punctured as a result of chafing with the high 
profile duct clamp. Further investigation revealed that the high 
profile duct clamp, which was lockwired to the anchor clamp, was 
installed in accordance with the requirements of AD 91-05-19. Due to 
failure of the lockwire, the high profile clamp rotated and chafed the 
fuel line in the strut of the number 4 engine. This condition, if not 
corrected, could result in rupture of the fuel line and a subsequent 
in-flight engine fire.
    The FAA has reviewed and approved Service Bulletin 747-36A2097, 
Revision 3, dated September 28, 1995, which describes procedures for 
modification of the upper gap area of the strut of the number 1 and 4 
engines. The modification involves an inspection to detect chafing or 
puncture marks of the fuel line, and replacement or repair of the 
chafed or punctured fuel line. The 

[[Page 2731]]
modification also involves replacement of the high profile clamp on the 
flap drive pneumatic duct with a low profile clamp, and removal of the 
anchor clamp, if installed. Accomplishment of this modification will 
eliminate chafing of the fuel line in the strut of the number 1 and 4 
engines.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would supersede AD 91-05-19 to require modification of the 
upper gap area of the strut of the number 1 and 4 engines. The actions 
would be required to be accomplished in accordance with the service 
bulletin described previously.
    There are approximately 363 Boeing Model 747-200, -300, -400 series 
airplanes equipped with General Electric Model CF6-80C2 PMC and CF6-
80C2 FADEC engines, and Pratt & Whitney Model PW4000 engines of the 
affected design in the worldwide fleet. The FAA estimates that 39 
airplanes of U.S. registry would be affected by this proposed AD.
    The actions that are proposed in this AD action would take 
approximately 6 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts would be supplied by 
the manufacturer at no cost to the operators. Based on these figures, 
the cost impact on U.S. operators of the proposed requirements of this 
AD is estimated to be $14,040, or $360 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the current or proposed 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.
    The regulations proposed herein would not have substantial direct 
effects 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.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities under 
the criteria of the Regulatory Flexibility Act. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g) 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-6918 (56 FR 
8705, March 1, 1991), and by adding a new airworthiness directive (AD), 
to read as follows:

Boeing: Docket 95-NM-162-AD. Supersedes AD 91-05-19, Amendment 39-
6918.

    Applicability: Model 747-200, -300, and -400 series airplanes 
having line positions 679 through 1041 inclusive; equipped with 
General Electric Model CF6-80C2 PMC and CF6-80C2 FADEC, and Pratt & 
Whitney Model PW4000 engines; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must use the authority 
provided in paragraph (b) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent chafing of the fuel line in the strut of the number 1 
and 4 engines, which could result in rupture of the fuel line and 
subsequent in-flight engine fire, accomplish the following:
    (a) Within 6 months after the effective date of this AD, modify 
the upper gap area of the strut of the number 1 and 4 engines, in 
accordance with Boeing Service Bulletin 747-36A2097, Revision 3, 
dated September 28, 1995.
    (b) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Seattle ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (c) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

    Issued in Renton, Washington, on January 22, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-1570 Filed 1-26-96; 8:45 am]
BILLING CODE 4910-13-U