Airworthiness Directives; Boeing Model 747 Series Airplanes

[Federal Register Volume 66, Number 239 (Wednesday, December 12, 2001)]
[Rules and Regulations]
[Pages 64105-64107]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-30205]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-217-AD; Amendment 39-12546; AD 2001-24-29]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 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 747 series airplanes, that requires 
a one-time inspection for chafing between the hose for the passenger 
oxygen system (hereinafter called the ``oxygen hose'') and adjacent 
electrical wire bundles at certain passenger service units, and 
corrective actions, if necessary. This AD also requires rerouting or 
reorienting the oxygen hose to ensure sufficient clearance between the 
hose and electrical wire bundles. This action is necessary to prevent 
chafing between the oxygen hose and adjacent electrical wire bundles, 
which could result in arcing of a chafed electrical wire bundle and 
consequent burn-through of the oxygen hose. If this occurs when the 
oxygen system is pressurized, such arcing could represent a potential 
ignition source in an oxygen-enriched environment. This action is 
intended to address the identified unsafe condition.

DATES: Effective January 16, 2002.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 16, 2002.

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 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

[[Page 64106]]

Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 747 series 
airplanes was published in the Federal Register on July 23, 2001 (66 FR 
38206). That action proposed to require a one-time inspection for 
chafing between the hose for the passenger oxygen system (hereinafter 
called the ``oxygen hose'') and adjacent electrical wire bundles at 
certain passenger service units (PSU), and corrective actions, if 
necessary. That action also proposed to require rerouting or 
reorienting the oxygen hose to ensure sufficient clearance between the 
hose and electrical wire bundles.

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 from a single commenter.

Request To Extend Compliance Time

    The commenter requests that the FAA extend the compliance time for 
the actions in the proposed AD from 12 months to 18 months after the 
effective date of the AD. The commenter states that it will take about 
40 work hours per airplane to do the proposed actions, and this work 
would best be performed during a heavy maintenance check where 
appropriate time and expertise is available.
    The FAA concurs with the commenter's request. We find that such an 
increase in the compliance time will not adversely affect safety and 
will allow the required actions to be completed during a regularly 
scheduled maintenance visit. We have revised paragraph (a) of this AD 
accordingly.

Request To Limit Applicability

    The commenter requests that the FAA revise the proposed AD to state 
that only airplanes with PSU configurations delivered by Boeing and as 
shown in Boeing Alert Service Bulletin 747-35A2035 are subject to the 
proposed AD. The commenter states that it has accomplished extensive 
interior modifications and replaced the PSUs on its airplanes through a 
supplemental type certificate.
    The FAA does not concur with the commenter's request. We do not 
consider the illustrations contained in Boeing Alert Service Bulletin 
747-35A2035, Revision 1, dated July 22, 1999, as revised by Boeing 
Service Bulletin Information Notice 747-35A2035 IN 01, dated September 
23, 1999, to be an adequate method of establishing the applicability of 
this AD. Because the service bulletin does not indicate that the 
chafing condition is limited to specific PSU part numbers, all 
airplanes identified in the effectivity listing of the service bulletin 
must be considered to be subject to the identified unsafe condition. 
Note 1 of this AD states that, for airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the operator must request approval for an 
alternative method of compliance in accordance with paragraph (b) of 
this AD. No change to the final rule is necessary 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 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 469 Model 747 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 166 
airplanes of U.S. registry will be affected by this AD, and that the 
average airplane has approximately 150 PSUs installed (though the 
actual number varies considerably between airplane configurations). It 
will take approximately 38 work hours per airplane (0.25 work hours per 
PSU) to accomplish the required actions, at the average labor rate of 
$60 per work hour. Required parts will cost approximately $5,250 per 
airplane ($35 per PSU). Based on these figures, the cost impact of this 
AD on U.S. operators is estimated to be $1,249,980, or $7,530 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.
    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:

2001-24-29  Boeing: Amendment 39-12546. Docket 2001-NM-217-AD.

    Applicability: Model 747 series airplanes, as listed in Boeing 
Alert Service Bulletin 747-35A2035, Revision 1, dated July 22, 1999; 
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 (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

[[Page 64107]]

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 between the oxygen hose and electrical wire 
bundles at certain passenger service units, which could result in 
arcing of a chafed wire bundle and consequent burn-through of the 
oxygen hose, with the arcing potentially representing an ignition 
source in an oxygen-enriched environment, accomplish the following:

Inspection and Follow-On Actions

    (a) Within 18 months after the effective date of this AD, do a 
detailed visual inspection for chafing between oxygen hoses and 
electrical wire bundles at the passenger service units (PSU) in the 
main deck passenger compartment, upper deck sculpted ceiling, 
personnel accommodation (crew rest) area, lower lobe forward galley, 
and aft galley; as applicable. Do the inspection according to Boeing 
Alert Service Bulletin 747-35A2035, Revision 1, dated July 22, 1999, 
as revised by Boeing Service Bulletin Information Notice 747-35A2035 
IN 01, dated September 23, 1999. Before further flight following 
this inspection, do the corrective actions in paragraphs (a)(1) and 
(a)(2) of this AD, as applicable, and reroute the oxygen hose or 
install an elbow at the oxygen mask inlet connector to reorient the 
oxygen hose away from the electrical wiring, as applicable, to 
ensure a minimum of 2 inches clearance between the oxygen hose and 
electrical wire bundle, according to the service bulletin.

    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.''

    (1) If any chafing of an oxygen hose is found: Replace the 
chafed oxygen hose with a new oxygen hose, and install protective 
sleeving over the new oxygen hose, according to the service 
bulletin.
    (2) If any chafing of a wire bundle is found, repair the wire 
bundle according to the service bulletin.

    Note 3: Inspections and follow-on actions done prior to the 
effective date of this AD according to Boeing Service Bulletin 747-
35-2035, dated January 7, 1983, are acceptable for compliance with 
corresponding actions in paragraph (a) of this AD.

Alternative Methods of Compliance

    (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, 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

    (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.

Incorporation by Reference

    (d) The actions shall be done in accordance with Boeing Alert 
Service Bulletin 747-35A2035, Revision 1, dated July 22, 1999, as 
revised by Boeing Service Bulletin Information Notice 747-35A2035 IN 
01, dated September 23, 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

    (e) This amendment becomes effective on January 16, 2002.

    Issued in Renton, Washington, on November 28, 2001.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-30205 Filed 12-11-01; 8:45 am]
BILLING CODE 4910-13-P

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