[Federal Register Volume 63, Number 28 (Wednesday, February 11, 1998)]
[Rules and Regulations]
[Pages 6840-6841]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-2827]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-222-AD; Amendment 39-10312; AD 98-03-20]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757 Series Airplanes

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 
one-time inspections to verify proper installation and to detect 
chafing and/or damage of certain rerouted wire bundles; to verify if 
certain protective grommets are installed properly and to detect 
missing grommets; and various follow-on actions. This amendment is 
prompted by a report of smoke and fire in the lower left-hand side of 
the E1-1 rack of the electrical equipment bay due to chafing of wire 
bundles as a result of missing protective grommets. The actions 
specified by this AD are intended to prevent chafing of wire bundles, 
which could result in smoke and fire at the E1-1 rack of the electrical 
equipment bay.

DATES: Effective March 18, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 18, 1998.

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: Forrest Keller, Senior Aerospace 
Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2790; 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 April 17, 1997 (62 
FR 18726). That action proposed to require one-time inspections to 
verify proper installation and to detect chafing and/or damage of 
certain rerouted wire bundles; to verify if certain protective grommets 
are installed properly and to detect missing grommets; and various 
follow-on actions.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    Several commenters support the proposed rule.

Request for Clarification

    One commenter suggests that the FAA provide clear and objective 
criteria in the proposed AD for determining if the wire bundle is too 
tight or too slack. The commenter states that sufficient clearance is 
very important when determining the length of a wire bundle. The FAA 
finds that clarification of this point is necessary. The FAA's intent 
was that operators refer to Boeing Standard Wiring Practices Manual 20-
10-11 (undated) for these procedures. Therefore, the FAA has revised 
paragraph (a)(1)(iii) of the final rule to include a reference to this 
manual as the appropriate source of service information for correction 
of discrepancies.

[[Page 6841]]

Conclusion

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

Cost Impact

    There are approximately 62 Boeing Model 757 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 28 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 2 work hours per airplane to accomplish the required 
actions, and that the average labor rate is $60 per work hour. The cost 
of required parts will be nominal. Based on these figures, the cost 
impact of the AD on U.S. operators is estimated to be $3,360, or $120 
per airplane.
    The cost impact figure discussed above is 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.

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.
    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:

98-03-20  Boeing: Amendment 39-10320. Docket 96-NM-222-AD.

    Applicability: Model 757 series airplanes, on which Boeing Alert 
Service Bulletin 757-24A0025, dated May 10, 1985, and/or Boeing 
Service Bulletin 757-24A0025, Revision 1, dated December 17, 1987, 
has been accomplished; excluding variable numbers NA003, NA004, 
NA007, NA009, NA010, NA012 through NA016 inclusive, and NA021; 
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 request approval for an 
alternative method of compliance in accordance with paragraph (b) 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 chafing of wire bundles, which could result in smoke 
and fire at the E1-1 rack of the electrical equipment bay, 
accomplish the following:
    (a) Within 6 months after the effective date of this AD, 
accomplish paragraphs (a)(1), (a)(2), and (a)(3) of this AD.
    (1) Perform a one-time inspection to verify proper installation 
and to detect chafing and/or damage of the wire bundles, having part 
numbers (P/N) W4508, W2608, and W2604. Pay particular attention to 
the area where the wire bundles are routed through the web supports 
and the area over the edge of intercostal R-23L.
    (i) If the wire bundles are installed properly and no chafing or 
damage is detected, no further action is required by this paragraph.
    (ii) If any chafing or damage is detected, prior to further 
flight, repair it in accordance with Boeing Standard Wiring 
Practices Manual 20-10-13 (not dated).
    (iii) If any wire bundle is installed improperly, prior to 
further flight, loosen the wire bundle clamps, adjust the wire 
bundles to achieve proper clearances, and retighten the wire bundle 
clamps, in accordance with Boeing Standard Wiring Practices Manual 
20-10-11 (not dated).
    (2) Perform a one-time inspection to verify if all protective 
grommets identified in Boeing Alert Service Bulletin 757-24A0025, 
dated May 10, 1985, are installed properly and to detect missing 
grommets. If any grommet is improperly installed or missing, prior 
to further flight, replace the grommet with a new grommet or install 
a new grommet, as applicable, in accordance with the alert service 
bulletin.
    (3) Perform a one-time inspection to determine if a protective 
grommet is installed on the upper edge of intercostal R-23L at 
approximately station 450 between the intercostal and wire bundles 
having P/N's W2608 and W4508. If no protective grommet is installed, 
prior to further flight, install one between the wire bundles and 
intercostal, in accordance with Boeing Production Installation 
Drawing 288N4329, Revision H, Sheets 1 and 2 (undated).
    (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, Manager, Seattle Aircraft 
Certfication 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.
    (d) Certain actions shall be done in accordance with Boeing 
Alert Service Bulletin 757-24A0025, dated May 10, 1985, Boeing 
Production Installation Drawing 288N4329, Revision H, Sheets 1 and 2 
(not dated), Boeing Standard Wiring Practices Manual 20-10-11 (not 
dated), and Boeing Standard Wiring Practices Manual 20-10-13 (not 
dated). 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.
    (e) This amendment becomes effective on March 18, 1998.

    Issued in Renton, Washington, on January 30, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-2827 Filed 2-10-98; 8:45 am]
BILLING CODE 4910-13-U