[Federal Register Volume 64, Number 69 (Monday, April 12, 1999)]
[Rules and Regulations]
[Pages 17524-17526]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-8957]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-292-AD; Amendment 39-11125; AD 99-08-19]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Boeing Model 747 series airplanes. This action 
requires replacement of the auxiliary power unit (APU) fuel boost pump 
with a serviceable pump. This amendment is prompted by findings from a 
design review and analysis, conducted as part of an accident 
investigation, of APU fuel boost pumps installed on certain Boeing 
Model 747 series airplanes. The actions specified in this AD are 
intended to prevent potential failures within the electrical motor 
assembly of the APU fuel boost pump (which could result in leakage of 
fuel from the electrical connector) or electrical arcing across the 
connector pins of the pump, and consequent fuel fire.

DATES: Effective April 27, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of April 27, 1999.
    Comments for inclusion in the Rules Docket must be received on or 
before June 11, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-292-AD, 1601 Lind Avenue, SW, Renton, 
Washington 98055-4056.
    The service information referenced in this AD 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; or at 
the Office of the Federal Register, 800 North Capitol Street, NW, Suite 
700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Chris Hartonas, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane 
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, 
SW, Renton, Washington 98055-4056; telephone (425) 227-2864; fax (425) 
227-1181.

SUPPLEMENTARY INFORMATION: As part of the accident investigation into 
the TWA Flight 800 accident of July 1996, the FAA participated in an 
engineering design review and analysis of the electrical connectors of 
Lear Romec auxiliary power unit (APU) fuel boost pumps. It has been 
determined that the Lear Romec component maintenance manual specifies 
an incorrect part number for that connector. Electrical connectors of 
Lear Romec APU fuel boost pumps incorporate a silicone insulating 
material. The results of that review and analysis indicate that contact 
with fuel can deteriorate the silicone insulating material in the 
electrical connectors during normal APU operation, due to the silicone 
material's incompatibility with fuel. Damage to the electrical 
connectors could cause failures within the electrical motor assembly of 
the APU fuel boost pump, which is located at the left-hand rear spar-
to-landing-gear support beam. Such failures of the APU fuel boost pump 
could result in fuel leakage from the electrical connector, or the 
possibility of electrical arcing across the connector pins of the pump, 
and, if not corrected, could result in a fuel fire.

Other Relevant Rulemaking

    On November 26, 1997, the FAA issued AD 97-25-06, amendment 39-
10230 (62 FR 63622, December 1, 1997).

[[Page 17525]]

[A correction of the rule was published in the Federal Register on 
January 2, 1998 (63 FR 4).] That AD required disconnection of the 
electrical connector to the scavenge pump of the center wing tank; a 
one-time inspection to identify the part number of the electrical 
connector; and replacement of the pump with a new pump, if necessary. 
The intent of that AD is to prevent potential failures within the 
electrical motor assembly of the scavenge pump on certain Boeing Model 
747 series airplanes; such failures could result in leakage of fuel 
from the electrical connector into the main landing gear wheel well, or 
electrical arcing within the scavenge pump motor, and consequent fuel 
fire in the wheel well.
    Since the issuance of AD 97-25-06, the FAA received a report of 
damage to the internal wiring of a scavenge pump. The connector of that 
scavenge pump had been replaced with a Lear Romec-supplied connector, 
in accordance with the requirements of AD 97-25-06. AD 97-25-06 was 
superseded by AD 98-14-17, amendment 39-10650 (63 FR 36836, July 8, 
1998), to require a one-time inspection to identify the scavenge pump 
motor-impeller unit and to require replacement of a certain Lear Romec 
pump.
    Certain electrical connectors on APU fuel boost pumps manufactured 
by Lear Romec incorporate the same silicone insulating material as that 
used on those scavenge pump connectors. The unsafe condition and its 
cause, as identified in AD 98-14-17, are similar to those addressed in 
this amendment.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 747-
28A2209, Revision 1, dated February 18, 1999, which describes 
procedures for a one-time visual inspection to identify the part number 
of the APU fuel boost pump. The service bulletin also describes 
procedures for replacement of any Lear Romec APU boost pump having an 
unacceptable part number, and provides two choices for the replacement 
pump: a pump that has been reworked, or a pump that has been 
manufactured by another supplier. Accomplishment of the actions 
specified in the service bulletin is intended to adequately address the 
identified unsafe condition, except as described below.

Differences Between AD and Relevant Service Information

    The effectivity of the service bulletin specifies certain line 
positions. The applicability of this AD is further limited to those 
airplanes installed with certain boost pumps. (The only action required 
by this AD is the replacement of those boost pumps.)

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, this AD is 
being issued to prevent potential failures within the electrical motor 
assembly of the APU fuel boost pump, which could result in leakage of 
fuel from the electrical connector, or electrical arcing across the 
connector pins of the pump, and consequent fuel fire. This AD requires 
accomplishment of the actions specified in Boeing Service Bulletin 747-
28A2209, Revision 1.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications shall identify the Rules Docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-NM-292-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket.
    A copy of it, if filed, may be obtained from the Rules Docket at 
the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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.

[[Page 17526]]

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

99-08-19  BOEING: Amendment 39-11125. Docket 98-NM-292-AD.

    Applicability: Model 747 series airplanes, line positions 001 
through 1150 inclusive; equipped with an auxiliary power unit (APU) 
fuel boost pump manufactured by Lear Romec and having Lear Romec 
part number (P/N) RR24640B; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
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 request approval for an 
alternative method of compliance in accordance with paragraph (c) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent potential failures within the electrical motor 
assembly of the APU fuel boost pump, which could result in fuel 
leakage from the electrical connector, or electrical arcing across 
the connector pins of the pump, and consequent fuel fire, accomplish 
the following:
    (a) Within 90 days after the effective date of this AD, replace 
the APU fuel boost pump as specified by either paragraph (a)(1) or 
(a)(2) of this AD, in accordance with Boeing Service Bulletin 747-
28A2209, Revision 1, dated February 18, 1999.
    (1) Replace the pump with a pump that has been reworked in 
accordance with the service bulletin. Or
    (2) Replace the pump with an FAA-approved pump manufactured by a 
supplier other than Lear Romec, in accordance with the service 
bulletin.
    (b) As of the effective date of this AD, no person shall install 
on any airplane an APU fuel boost pump having Lear Romec P/N 
RR24640B.
    (c) 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.

    (d) 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.
    (e) The replacement shall be done in accordance with Boeing 
Service Bulletin 747-28A2209, Revision 1, dated February 18, 1999. 
This incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Boeing Commercial Airplane Group, 
P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be 
inspected at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
    (f) This amendment becomes effective on April 27, 1999.

    Issued in Renton, Washington, on April 5, 1999.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-8957 Filed 4-9-99; 8:45 am]
BILLING CODE 4910-13-U