[Federal Register Volume 66, Number 61 (Thursday, March 29, 2001)]
[Proposed Rules]
[Pages 17123-17125]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-7737]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-318-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 707 and 720 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 707 and 720 
series airplanes. This proposal would require replacement of wiring for 
the fuel boost pumps and override pumps with new wiring, installation 
of Teflon sleeving on the wiring, and associated actions. This proposal 
also would require repetitive inspections to detect damage of the 
wiring or evidence of a fuel leak. This action is necessary to detect 
and correct damaged wiring for the fuel boost pumps and override pumps, 
which could cause electrical arcing that could puncture the conduit 
containing the wire, and result in an explosion or fire adjacent to the 
fuel tank. This action is intended to address the identified unsafe 
condition.

DATES: Comments must be received by May 14, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-318-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. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-318-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    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: Sulmo Mariano, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone 
(425) 227-2686; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the

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proposed 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 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-318-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-114, Attention: Rules 
Docket No. 2000-NM-318-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report that, while investigating a fuel leak 
around the bolts on the number 1 fuel boost pump on a Boeing Model 707 
series airplane, an operator found wire damage where the fuel boost 
pump wiring exited the boost pump and entered the boost pump access 
area. (The damage is generated by movement of the wire against an 
adjacent surface, which is due to normal vibrations of the airplane.) 
Electrical wiring for the fuel boost pump is contained inside a 
metallic conduit installed in the fuel tank. Damaged wiring for the 
fuel boost pumps, if not corrected, could cause electrical arcing that 
could puncture the conduit containing the wiring, and result in an 
explosion or fire adjacent to the fuel tank. The installation of wiring 
for the fuel override pumps is similar; thus, wiring for the fuel 
override pumps could also be subject to the same unsafe condition.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
A3500, dated July 27, 2000, which describes procedures for replacement 
of wiring for the fuel boost pumps and override pumps, and associated 
actions. The associated actions described in the service bulletin 
include the following:
     Inspecting the area of the fuel boost pumps and override 
pumps to find evidence of a fuel leak, and locating the source of any 
fuel leak detected in that area;
     Removing the wiring of the fuel boost pumps and override 
pumps and inspecting it for damage, such as evidence of electrical 
arcing or exposed copper wire, or evidence of a fuel leak;
     Replacing the conduit where any electrical arcing or fuel 
leakage has occurred;
     Installing new wiring for each fuel boost pump and 
override pump; and
     Installing Teflon sleeving over the new wiring.
    Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

    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 require accomplishment of the actions specified in 
the service bulletin described previously, except as discussed below.
    The proposed AD would also require repetitive detailed visual 
inspections for damage (e.g., evidence of electrical arcing or exposed 
copper wire) of the fuel boost pump and override pump wiring or 
evidence of a fuel leak at least every 30,000 flight hours after 
replacement of the wiring. The FAA based the decision to propose these 
repetitive inspections on several factors, including the degree of 
urgency associated with this unsafe condition. In view of the 
considerations associated with wiring of the fuel boost pumps and 
override pumps, the FAA finds it necessary to propose repetitive 
inspections.

Explanation of Compliance Time

    This proposed AD would require accomplishment of the initial 
inspection and replacement of wiring within 1 year or 4,000 flight 
hours after the effective date of the AD, whichever occurs first. In 
developing an appropriate compliance time for this proposed AD, the FAA 
considered not only the manufacturer's recommendation, but the degree 
of urgency associated with addressing the subject unsafe condition and 
the average utilization of the affected fleet. In light of all of these 
factors, the FAA finds this compliance time warranted, in that it 
represents an appropriate interval of time allowable for affected 
airplanes to continue to operate without compromising safety.

Cost Impact

    There are approximately 261 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 65 airplanes of U.S. registry 
would be affected by this proposed AD.
    The proposed replacement and initial associated actions would take 
approximately 27 work hours per airplane, at the average labor rate of 
$60 per work hour. Based on these figures, the FAA estimates the cost 
impact of these proposed actions on U.S. operators to be $105,300, or 
$1,620 per airplane.
    The inspection for damage of the wiring or evidence of a fuel leak 
would take approximately 3 work hours per airplane, at the average 
labor rate of $60 per work hour. Based on these figures, the FAA 
estimates the cost impact of this inspection on U.S. operators to be 
$11,700, or $180 per airplane, per inspection cycle.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed requirements 
of this AD action, and that no operator would accomplish those actions 
in the future if this proposed AD were not adopted. The cost impact 
figures discussed in AD rulemaking actions represent only the time 
necessary to perform the specific actions actually required by the AD. 
These figures typically do not include incidental costs, such as the 
time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect on the States, on the relationship between the national 
Government and

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the States, or on the distribution of power and responsibilities among 
the various levels of government. Therefore, it is determined that this 
proposal would not have federalism implications under Executive Order 
13132.
    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 adding the following new 
airworthiness directive:
Boeing:  Docket 2000-NM-318-AD.

    Applicability: Model 707 and 720 series airplanes, line numbers 
1 through 941 inclusive, 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 detect and correct damaged wiring for the fuel boost pumps 
and override pumps, which could cause electrical arcing that could 
puncture the conduit containing the wire and result in an explosion 
or fire adjacent to the fuel tank, accomplish the following:

Replacement of Wiring, Installation of Sleeving, and Associated Actions

    (a) Within 1 year or 4,000 flight hours after the effective date 
of this AD, whichever occurs first, replace the wiring for the fuel 
boost pumps and override pumps, install Teflon sleeving over the 
wiring, and do all associated actions, per the Accomplishment 
Instructions of Boeing Alert Service Bulletin A3500, dated July 27, 
2000. The associated actions include performing a general visual 
inspection of the area around each fuel boost pump and override pump 
for evidence of a fuel leak; finding the source of any fuel leak and 
repairing the affected area; replacing the conduit, if required; and 
performing a detailed visual inspection of the wiring installed in 
the conduit for evidence of electrical arcing or a fuel leak, or 
exposed copper wire. If replacement of the conduit is deferred per 
the service bulletin, repeat the inspection for fuel leaks every 500 
flight hours until the conduit is replaced, and replace the conduit 
within 6,000 flight hours or 18 months, whichever occurs first.

    Note 2: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or drop-light, and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''


    Note 3: For the purposes of this AD, a detailed visual 
inspection is defined as: ``An intensive visual examination of a 
specific structural area, system, installation, or assembly to 
detect damage, failure, or irregularity. Available lighting is 
normally supplemented with a direct source of good lighting at 
intensity deemed appropriate by the inspector. Inspection aids such 
as mirror, magnifying lenses, etc., may be used. Surface cleaning 
and elaborate access procedures may be required.''

Repetitive Inspections

    (b) After replacement of the wiring per paragraph (a) of this 
AD, repeat the detailed visual inspection of the wiring for the fuel 
boost pumps and override pumps for damage, such as evidence of 
electrical arcing or exposed copper wire, or evidence of a fuel 
leak. Repeat the inspection at least every 30,000 flight hours, per 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
A3500, dated July 27, 2000. If any discrepancy is detected during 
any inspection per this paragraph, before further flight, replace 
the wiring and conduit, and install new Teflon sleeving.

Alternative Methods of Compliance

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

Special Flight Permits

    (d) Special flight permits may be issued in accordance with 
Secs. 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 March 23, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-7737 Filed 3-28-01; 8:45 am]
BILLING CODE 4910-13-U