[Federal Register Volume 69, Number 220 (Tuesday, November 16, 2004)]
[Rules and Regulations]
[Pages 67047-67050]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-25189]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-74-AD; Amendment 39-13861; AD 2004-23-06]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757-200, -200PF, -200CB, 
and -300 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 757-200, -200PF, -200CB, and -300 
series airplanes, that requires inspection for damage of the W2800 wire 
bundle insulation, wire conductor, the wire bundle clamp bracket, and 
the BACC10GU( ) clamp, and repair or replacement with new or 
serviceable parts, if necessary. This amendment also requires 
installation of spacers between the clamp and the bracket. This action 
is necessary to prevent contact between the power feeder wires of the 
auxiliary power unit (APU) and the clamp bracket aft of the STA 1720 
bulkhead due to chafing damage of the Adel clamp and ``L'' shaped 
bracket, which could result in electrical arcing and fire, or loss of 
APU electrical power in the airplane. This action is intended to 
address the identified unsafe condition.

DATES: Effective December 21, 2004.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 21, 2004.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplanes, 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 National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call (202) 741-6030, or go to: 
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

FOR FURTHER INFORMATION CONTACT: Elias Natsiopoulos, Aerospace 
Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6478; fax (425) 917-6590.

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 757-200, -
200PF, -200CB, and -300 series airplanes was published in the Federal 
Register on June 14, 2002 (67 FR 40894). That action proposed to 
require inspection for damage of the W2800 wire bundle insulation, wire 
conductor, the wire bundle clamp bracket, and the BACC10GU( ) clamp, 
and repair or replacement with new or serviceable parts, if necessary. 
That action also proposed to require installation of spacers between 
the clamp and the bracket.

Since the Issuance of the Proposed AD

    Since the issuance of the proposed AD, Boeing has issued Special 
Attention Service Bulletins 757-24-0089, Revision 1, and 757-24-0090, 
Revision 1, both dated February 27, 2003. Except for the addition of an 
auxiliary power unit (APU) generator system test to be accomplished if 
damage is found on the W2800 wire bundle, the service bulletins are 
essentially identical to the original service bulletins, both dated 
March 15, 2001. The original issue service bulletins were referenced in 
the proposed AD as the appropriate sources of service information for 
the required actions.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposed AD

    One commenter has no objection to the proposed AD.

Request To Extend the Compliance Time

    One commenter requests that the compliance time for the general 
visual inspections be extended from 15 months to 24 months. The 
commenter states that it has found no chafing damage to the wire bundle 
on its airplanes. Therefore, the commenter states the extension of 
compliance time will allow the inspections to be performed during 
scheduled heavy maintenance checks, which are scheduled every 24 
months.
    The FAA agrees that the compliance time for the accomplishment of 
the general visual inspections may be extended somewhat. We have 
reassessed the compliance time and considered the manufacturer's 
recommendation of a compliance time of 18 months for the general visual 
inspection. In addition, we have determined that, for airplanes on 
which no damage is found and there is a 0.25-inch minimum clearance 
between the wire bundles and aft edge of the bracket, the compliance 
time for accomplishing the follow-on actions (installing the spacers 
and ensuring the minimum clearance) may be extended from ``before 
further flight'' to ``24 months after the effective date of this AD'' 
for those follow-on actions. We consider that such an extension of the 
compliance time for the follow-on actions will not adversely affect the 
adequate safety of flight of the airplane. The requirements of 
paragraph (a) of the AD have been revised accordingly.

Request To Remove the Requirement To Install Spacers

    One commenter requests that the requirement to install spacers be 
removed from the proposed AD. The commenter states that it inspected 
wire bundle W2800 on an airplane in its fleet that did not have 
spacers, and the

[[Page 67048]]

inspection revealed that there was at least \1/4\-inch clearance 
between the bracket and wire bundle. The commenter asserts that correct 
positioning of the wire bundle, without the installation of spacers, 
will prevent interference between the bundle and bracket.
    The FAA does not agree to remove the requirement to install 
spacers. Installing spacers will ensure that appropriate clearance is 
maintained between the bracket and wire bundle. However, as discussed 
in our response above, we have revised paragraph (a) of this AD to 
extend the compliance time to 24 months for installation of the spacers 
for certain airplanes.

Request To Allow Damage Where Certain Tolerances Are Not Exceeded

    One commenter requests that the proposed AD allow certain damage to 
exist where certain damage tolerance limits are not exceeded. The 
commenter states that there should be no requirement to repair or 
replace a wire bundle or its attaching hardware when it meets 
acceptable damage tolerances. The commenter points out that, in those 
cases, only repositioning is necessary, rather than repair or 
replacement, to prevent further damage.
    The FAA partially agrees with the commenter. We have determined 
that it is unnecessary to ``repair or replace'' for those cases where 
damage to the wire bundle is within certain limits. However, there are 
no acceptable damage limits for the clamp bracket or the BACC10GU( ) 
clamp. Therefore, the final rule specifies that any damage to the clamp 
bracket or the BACC10GU( ) clamp requires replacement of the applicable 
part. We have revised the final rule to specify that the damage 
tolerance limits for the wire bundle must be approved by the Seattle 
Aircraft Certification Office (ACO), FAA. Damage limits specified in 
Chapter 20-10-13 the Boeing Standard Wiring Practices Manual (BSWPM) 
are also approved as a source to identify specific damage limits.

Request To Permit Interim Repair

    One commenter states that the repair for damaged wires as specified 
in the BSWPM, referenced in the applicable service bulletin, requires 
replacement or repair by splicing any wire when damage extends to the 
conductor. The commenter notes that, in this case, the affected area 
does not allow sufficient distance to install a repair splice. The 
commenter advises that the only way to repair such a damaged conductor 
is to install a repair splice inside of the pressurized area and run 
the other end to the production ALCU splice at B STA 1862. The 
commenter further states that this procedure will require the removal 
of a galley and certain cabin panels, which will increase the length of 
time needed to accomplish the corrective action. Additionally, the 
commenter recommends the following actions instead of wire replacement 
with the following limitations:
     In the case of a single damaged conductor (one nicked 
strand, no broken strands), perform an interim insulation repair per 
BSWPM Chapter 20-10-13 and repair the clamp per the service bulletin.
     Replace the interim wire repair at the next C check, with 
a permanent wire splice per BSWPS Chapters 20-10-13 and 20-30-13 at B 
STA 1640.
    The commenter asserts that those actions would provide an 
equivalent level of safety and allow minimal interruption of service.
    We agree that, in the case of a single damaged conductor (one 
nicked strand, no broken strands), an interim insulation repair may be 
performed per the BSWPM under the following condition: The interim wire 
repair is replaced per the BSWPM within 6,000 flight hours from the 
accomplishment date of the interim repair. We have added new paragraph 
(c) of the AD to address accomplishment of the interim repair.

Request To Clarify Cost Information

    This same commenter notes that the cost impact for accomplishing 
the repair of a damaged wire by splicing may significantly increase the 
cost of this AD. The commenter states that it would take approximately 
65 work hours per airplane to perform that type of repair.
    We acknowledge that if an operator is required to perform an ``on-
condition'' repair, the costs of accomplishing the AD may increase. 
However, the economic analysis of an AD is limited to the cost of 
actions that are actually required. The economic analysis does not 
consider the costs of conditional actions, such as repairing damage 
detected during a required inspection (``repair, if necessary''), or as 
in this case, an alternative interim repair. Conditional costs would be 
required, regardless of AD direction, to correct an unsafe condition 
identified in an airplane and to ensure that the airplane is operated 
in an airworthy condition is required by the Federal Aviation 
Regulations. Therefore, no change to the ``Cost Impact'' section is 
required to this AD in this regard.

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.

Changes to 14 CFR Part 39/Effect on the AD

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. The regulation now includes material that relates to 
altered products, special flight permits, and alternative methods of 
compliance. However, for clarity and consistency in this final rule, we 
have retained the language of the NPRM regarding that material.

Cost Impact

    There are approximately 934 Boeing Model 757-200, -200PF, -200CB, 
and -300 series airplanes of the affected design in the worldwide 
fleet. The FAA estimates that 595 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 1 work hour per 
airplane to accomplish the required actions, and that the average labor 
rate is $65 per work hour. Based on these figures, the cost impact of 
the AD on U.S. operators is estimated to be $38,675, or $65 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. 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.

[[Page 67049]]

    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

0
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

0
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]

0
2. Section 39.13 is amended by adding the following new airworthiness 
directive:

2004-23-06 Boeing: Amendment 39-2004-23-06. Docket 2001-NM-74-AD.

    Applicability: Model 757-200, -200PF, -200CB, as listed in 
Boeing Special Attention Service Bulletin 757-27-0089, Revision 1; 
and Model 757-300 series airplanes, as listed in Boeing Special 
Attention Service Bulletin 757-24-0090, Revision 1; both service 
bulletin revisions dated February 27, 2003; 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 (d) 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 electrical contact between the power feeder wires of 
the auxiliary power unit (APU) and the clamp bracket aft of STA 1720 
bulkhead due to chafing damage of the Adel clamp and ``L'' shaped 
bracket, which could result in electrical arcing and fire or loss of 
electrical power in the airplane; accomplish the following:

Inspection and Repair

    (a) Within 18 months after the effective date of this AD, 
perform a general visual inspection for damage of the W2800 wire 
bundle insulation, wire conductor, wire bundle clamp bracket, and 
the BACC10GU( ) clamp; per Boeing Special Attention Service Bulletin 
757-24-0089, Revision 1, dated February 27, 2003 (for Boeing Model 
757-200 series airplanes); or Boeing Special Attention Service 
Bulletin 757-24-0090, Revision 1, dated February 27, 2003 (for 
Boeing Model 757-300 series airplanes); as applicable.

    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 from within 
touching distance unless otherwise specified. A mirror may be 
necessary to enhance visual access to all exposed surfaces in the 
inspection area. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or droplight 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.''

    (1) With the exception of the actions specified in paragraph (c) 
of this AD: For the conditions specified in paragraph (a)(1)(i), 
(a)(1)(ii), or (a)(1)(iii) of this AD, and in paragraph (a)(1)(iv) 
of this AD, within 24 months after the effective date of this AD, 
install spacers and ensure that there is the minimum clearance 
between the wire bundle and aft edge of the bracket, per the 
applicable service bulletin.
    (i) No damage is detected to the wire bundle insulation or the 
wire conductor,
    (ii) Damage is detected to the wire bundle insulation or the 
wire conductor that is within certain limits approved by the 
Manager, Seattle Aircraft Certification Office (ACO), FAA, or
    (iii) Damage is detected to the wire bundle insulation or the 
wire conductor that is within certain limits specified in Chapter 
20-10-13 of the BSWPM; and
    (iv) There is a 0.25-inch minimum clearance between the wire 
bundle and aft edge of the bracket.
    (2) With the exception of the actions specified in paragraph (c) 
of this AD: For the conditions specified in paragraphs (a)(2)(i), 
(a)(2)(ii), or (a)(2)(iii) of this AD, and in paragraph (a)(2)(iv) 
of this AD, before further flight, install spacers and ensure the 
minimum clearance between the wire bundle and aft edge of the 
bracket, per the applicable service bulletin.
    (i) No damage is detected to the wire bundle insulation or the 
wire conductor,
    (ii) Damage is detected to the wire bundle insulation or the 
wire conductor that is within certain limits approved by the 
Manager, Seattle Aircraft Certification Office (ACO), FAA, or
    (iii) Damage is detected to the wire bundle insulation or the 
wire conductor that is within certain limits specified in Chapter 
20-10-13 of the BSWPM; and
    (iv) There is less than 0.25-inch minimum clearance between the 
wire bundle and aft edge of the bracket.
    (3) If any damage is detected to the wire insulation or wire 
conductor and the damage is outside the damage limits approved by 
the Manager, Seattle ACO, or specified in Chapter 20-10-13 of the 
BSWPM: Before further flight, repair the damage per the applicable 
service bulletin.
    (4) If no damage is detected to the wire bundle clamp bracket or 
the BACC10GU( ) clamp: Within 24 months after the effective date of 
this AD, install spacers and ensure that there is 0.25-inch minimum 
clearance between the wire bundle and aft edge of the bracket; per 
the applicable service bulletin.
    (5) If any damage is detected to the wire bundle clamp bracket 
or the BACC10GU( ) clamp: Before further flight, replace the clamp 
bracket and the clamp with new or serviceable parts, install 
spacers, and ensure that there is 0.25-inch minimum clearance 
between the wire bundle and aft edge of the bracket; per the 
applicable service bulletin.

Acceptable Method of Compliance

    (b) Accomplishment of the actions specified in Boeing Service 
Bulletin 757-24-0089, dated March 15, 2001; or Boeing Service 
Bulletin 757-24-0090, dated March 15, 2001; as applicable, is 
considered acceptable for compliance with the requirements specified 
in paragraph (a) of this AD.

Interim Repair

    (c) If damage to a wire conductor is detected during any 
inspection required by paragraph (a) of this AD that only consists 
of one strand being nicked and no broken strands: Accomplish the 
actions specified in paragraph (c)(1), (c)(2), and (c)(3) of this AD 
at the time specified.
    (1) Prior to further flight, accomplish an interim repair of the 
insulation per a method approved by the Manager, Seattle ACO. For an 
interim repair method to be approved by the Manager, Seattle ACO, as 
required by this paragraph, the Manager's approval letter must 
specifically refer to this AD. Chapter 20-10-13 of the BSWPM is one 
approved method for accomplishing an interim repair.
    (2) Accomplish the actions at the time specified in either 
paragraph (a)(4) or (a)(5) of this AD, as applicable.
    (3) Within 6,000 flight hours after accomplishing the interim 
repair of the insulation specified in paragraph (c)(1) of this AD, 
replace the interim repair with a permanent repair, per a method 
approved by the Manager, Seattle ACO. For a permanent method to be 
approved by the Manager, Seattle ACO, as required by this paragraph, 
the Manager's approval letter must specifically refer to this AD. 
Accomplishing Chapters 20-10-13 and 20-30-13 of the BSWPM is one 
approved method for replacement of the interim repair with a 
permanent repair.

[[Page 67050]]

Alternative Methods of Compliance

    (d) 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 ACO. 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 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

    (e) Special flight permits may be issued in accordance with 
Sec. Sec.  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

    (f) Unless otherwise specified in this AD, the actions shall be 
done in accordance with Boeing Special Attention Service Bulletin 
757-24-0089, Revision 1, dated February 27, 2003; or Boeing Special 
Attention Service Bulletin 757-24-0090, Revision 1, dated February 
27, 2003. 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 National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call (202) 741-6030, or go 
to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

Effective Date

    (g) This amendment becomes effective on December 21, 2004.

    Issued in Renton, Washington, on November 3, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-25189 Filed 11-15-04; 8:45 am]
BILLING CODE 4910-13-U