AD 2001-13-15

[Federal Register Volume 66, Number 128 (Tuesday, July 3, 2001)]
[Rules and Regulations]
[Pages 35077-35080]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-16200]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-271-AD; Amendment 39-12296; AD 2001-13-15]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757 Series Airplanes 
Equipped with Rolls Royce Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 757 series airplanes, that requires 
a one-time inspection to find wire chafing of the left and right engine 
fuel shutoff valve wire bundles at Power Plant Station 278 on each 
engine strut, and repair if necessary. This amendment also requires 
replacement of three wire support brackets with improved wire support 
brackets. This amendment is prompted by reports that such wire support 
brackets failed due to fatigue, which subsequently caused the fuel 
shutoff valve wire to chafe and to experience a short circuit. The 
actions specified by this AD are intended to prevent such conditions, 
which could result in either the possible ignition of fuel vapors in a 
flammable leakage zone or in the inability to stop the flow of fuel in 
the event of an engine fire.

DATES: Effective August 7, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 7, 2001.

ADDRESSES: 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 Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 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: Stephen S. Oshiro, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2793; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 757 series 
airplanes was published in the Federal Register on August 4, 1999 (64 
FR 42050). That action proposed to require repetitive inspections to 
detect wire chafing of the left and right engine fuel shutoff valve 
wire bundles at Power Plant Station 278 on each engine strut, and 
repair if necessary. That action also proposed to require repetitive 
replacement of three wire support brackets with improved wire support 
brackets.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due

[[Page 35078]]

consideration has been given to the comments received.

Addition of Service Bulletin Information Notice

    One commenter, the airplane manufacturer, indicates that during its 
investigation of the wire support bracket failure it established that 
Boeing Service Bulletin 757-54-0013, Revision 3, dated October 23, 1997 
(cited in the proposal as the source of service information for doing 
the specified actions) contained an incorrect part number for an 
attachment fastener. The commenter adds that the part number was 
corrected in Boeing Information Notice 757-54-0013 IN 01, dated October 
22, 1998.
    The FAA infers that the commenter wants to add IN 01 to the service 
information cited in the final rule. Subsequent to receipt of this 
comment, we reviewed and approved Boeing Information Notice 757-54-0013 
IN 02, dated April 8, 1999, which supersedes IN 01. IN 02 contains 
additional information for proper accomplishment of the modifications 
described in the service bulletin, as well as the corrected part number 
specified by the commenter. We concur with the commenter's request, but 
will add IN 02 to the service information cited in the final rule.

Revise Paragraph (a)

    One commenter, the airplane manufacturer, states that it did an 
analysis of the new, improved wire support brackets to determine the 
fatigue level allowable. The analysis showed that the two lower 
aluminum brackets were undersized for the vibration environment in the 
aft strut area, and that the nickel alloy brackets were capable of 
withstanding the vibration environment, with fatigue allowables that 
exceed the stress levels by 80 percent. Analysis done on the third 
bracket showed that the aluminum brackets are also satisfactory. This 
analysis was conducted per standard Boeing practice for equipment in 
the nacelle and strut areas, using well-established stress values.
    Based on the above information, the commenter states that replacing 
all 6 brackets every 12 months is unnecessary and will impose a 
considerable economic burden on affected operators. The commenter 
proposes revising paragraph (a) of the proposed rule as follows:
    <bullet> Incorporate Boeing Service Bulletin 757-54-0013, Revision 
3, dated October 23, 1997, within 12 months after the effective date of 
the AD. This would constitute terminating action for the proposed rule. 
Or
    <bullet> For operators that do not incorporate the Revision 3 of 
the service bulletin, repetitively inspect the installation for chafing 
or damage of the wire bundle, and for cracked or fractured brackets. 
The repetitive inspection should be accomplished at intervals not to 
exceed 18 months, with bracket replacement if any evidence of cracking 
or damage is found.
    The FAA partially agrees with the commenter's proposal, as follows:
    We agree with the assessment that the replacement brackets 
specified in Revision 3 of the service bulletin are adequate to meet 
the strut vibration environment, and that incorporation of such 
replacement brackets would eliminate the need for the repetitive 
inspections and repetitive replacements of the wire support brackets 
specified in the proposed rule. Therefore, paragraphs (a) and (b) have 
been combined into paragraph (a) with the repetitive inspections and 
replacements omitted, and subsequent paragraphs have been re-numbered 
accordingly. Additionally, the preamble and the cost impact sections of 
the final rule have been changed.
    We do not agree with the commenter's proposal to allow continued 
use of the existing brackets with repetitive inspections beyond the 
initial 12-month compliance time. The commenter did not submit adequate 
justification for allowing the continued use of these brackets, or 
extending the compliance time for the repetitive inspections from 12 to 
18 months. The existing brackets can fail in service, and such failures 
could result in damage to wiring, ignition of fuel vapors in a 
flammable leakage zone, or loss of the fuel shutoff valve function. 
Considering these safety concerns, repetitive inspections without 
replacement of the wire support brackets after the doing the inspection 
would not adequately address the identified unsafe condition.

Withdraw Proposed Rule

    One commenter asks that the FAA withdraw the proposed rule. The 
commenter provided in service data showing that airplanes which have 
replaced the wire support brackets per Boeing Service Bulletin 757-54-
0013, Revision 3, have experienced no problems with the brackets. The 
commenter states that the annual bracket replacement (every 12 months) 
is not possible or practical because the repetitive bracket 
replacements would involve repetitive replacement of close tolerance 
fasteners, and would require repeated oversizing of the existing 
airplane mounting holes. This could result in the holes being too large 
for proper installation of the brackets. The commenter adds that a 
deviation to the proposed rule would be necessary each time the 
fasteners are replaced.
    The FAA concurs with the commenter's assessment that the brackets 
that were replaced per Revision 3 of the service bulletin are adequate; 
however, we do not agree with the request to withdraw the proposed 
rule. Failure to install the replacement brackets per the referenced 
service bulletin could result in the unsafe conditions stated under the 
previous section titled ``Revise Paragraph (a).'' Also stated in that 
section is our intent to omit the repetitive inspections and repetitive 
bracket replacements specified in paragraph (a) of the proposed rule. 
Paragraph (a) of the final rule has been revised to require a one-time 
inspection and one-time replacement of the wire support brackets.

Reduce Compliance Time

    One commenter asks that the FAA reduce the proposed compliance time 
for the initial inspection specified in paragraph (a) of the proposed 
rule from 12 months to 6 months after the effective date of the AD. The 
commenter states that 12 months is too long and notes that, based on 
previous administrative procedures and industry practices, it could be 
almost 18 months before an airplane is inspected. The commenter adds 
that this places the traveling public at an elevated risk and greatly 
reduces the margin of safety on the airplane.
    The FAA does not agree. As discussed in the section ``Differences 
Between Proposed Rule and Service Bulletin'' in the preamble of the 
proposed rule, we find that a 12-month compliance time for the initial 
inspection would address the unsafe condition in a timely manner. In 
developing an appropriate compliance time for the proposed AD, we 
considered not only the manufacturer's recommendation, but the degree 
of urgency associated with addressing the subject unsafe condition, the 
average utilization of the affected fleet, and the time necessary to do 
the initial inspection/modification.
    Operators are always permitted to accomplish the requirements of an 
AD at a time earlier than that specified as the compliance time; 
therefore, if an operator wants to do the initial inspection required 
by paragraph (a) of this AD earlier than 12 months after the effective 
date of the AD, the operator can do so. Therefore, no change to the 
compliance time for the initial inspection required by paragraph (a) of 
the final rule is necessary.

[[Page 35079]]

Extend Compliance Time

    One commenter states that the proposed 12-month compliance 
timetable for the bracket replacement is unrealistic and asks that the 
compliance time be extended to 18 months. The commenter notes that it 
is currently implementing the modification at its C-check, and requires 
18 months to modify its entire fleet. The commenter also states that 
the manufacturer has quoted a 22-month lead time for obtaining the 
necessary kits, which is not compatible with the timetable specified in 
the proposed rule.
    The FAA does not agree. As stated above, we find that a 12-month 
compliance time for the initial inspection/modification is appropriate.

Fuel Shutoff Valve (FSOV)

    One commenter notes that the FSOV can be closed using the redundant 
circuit routed on the front spar, as long as power is available to that 
circuit. The FAA agrees with the statement and infers that the 
commenter wants further explanation of the procedures available should 
this situation occur. This can occur only if the engine fuel cutoff 
switch is placed in the ``cutoff'' position before the engine fire 
handle is pulled. The procedural information is described in the 
Emergency Procedures section of the 757 Airplane Flight Manual.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 501 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 249 airplanes of U.S. registry 
will be affected by this AD.
    It will take approximately 2 work hours to accomplish the required 
inspection and approximately 6 work hours per airplane to accomplish 
the required replacement. The average labor rate is estimated to be $60 
per work hour. Required parts will cost approximately $525 per 
airplane. Based on these figures, the cost impact of the AD on U.S. 
operators is estimated to be $250,245, or $1,005 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this 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 adopted herein will not have a substantial direct 
effect 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, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it 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.


Sec. 39.13  [Amended]

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

2001-13-15  Boeing: Amendment 39-12296. Docket 98-NM-271-AD.

    Applicability: Model 757 series airplanes, certificated in any 
category, equipped with Rolls Royce engines.

    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 a short circuit that could result in either the 
possible ignition of fuel vapors in a flammable leakage zone or in 
the inability to stop the flow of fuel in the event of an engine 
fire, accomplish the following:

Inspection/Corrective Action

    (a) Within 12 months after the effective date of this AD, 
accomplish paragraphs (a)(1) and (a)(2) of this AD.
    (1) Do a one-time detailed visual inspection of the wire bundles 
that pass through the three wire support brackets located at Power 
Plant Station (PPS) 278 on each engine strut, to find wire chafing. 
If any chafing is found, before further flight, repair the wire 
bundle per the Boeing Standard Wiring Practices Manual, Document D6-
54446, Revision 23, dated August 1998.
    (2) Replace all three existing wire support brackets located at 
PPS 278 on each engine strut with new, improved wire support 
brackets, per Boeing Service Bulletin 757-54-0013, Revision 3, dated 
October 23, 1997, as revised by Boeing Information Notice 757-54-
0013 IN 02, dated April 8, 1999.

    Note 2: 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.''

Spares Paragraph

    (b) As of the effective date of this AD, no person shall install 
a wire support bracket having P/N 287N1112-8, -9, -20, or -21 on any 
airplane.

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

[[Page 35080]]

Inspector, who may add comments and then send it to the Manager, 
Seattle ACO.

    Note 3: 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 
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.

Incorporation by Reference

    (e) Except as provide by paragraph (a)(1) of this AD, the 
actions shall be done in accordance with Boeing Service Bulletin 
757-54-0013, Revision 3, dated October 23, 1997, as revised by 
Boeing Information Notice 757-54-0013 IN 02, dated April 8, 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.

Effective Date

    (f) This amendment becomes effective on August 7, 2001.

    Issued in Renton, Washington, on June 21, 2001.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-16200 Filed 7-2-01; 8:45 am]
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