Airworthiness Directives; Boeing Model 747-100, -200, and -300 Series Airplanes

[Federal Register Volume 63, Number 190 (Thursday, October 1, 1998)]
[Rules and Regulations]
[Pages 52587-52589]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-25952]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-85-AD; Amendment 39-10804; AD 98-20-37]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100, -200, 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 747-100, -200, and -300 series 
airplanes, that requires the replacement of certain switches located in 
the cabin attendant's panel at doors 1 and 3 right with new, improved 
switches. This amendment is prompted by reports indicating that fires 
have occurred on some airplanes due to the internal failure of some of 
these switches. The actions specified by this AD are intended to 
prevent the installation and use of such switches that could short 
circuit when they fail, and consequently cause fire and smoke aboard 
the airplane.

DATES: Effective November 5, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 5, 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; 
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 747-100, -
200, and -300 series airplanes was published in the Federal Register on 
May 30, 1997 (62 FR 29306). That action proposed to require the 
replacement of certain switches located in the cabin attendant's panel 
at doors 1 and 3 right with new, improved switches.

Actions Since Issuance of Proposal

    Since the issuance of the proposal, the FAA has received a report 
of incidents of burned switches and fire found behind the cabin 
attendant's switch panels at doors 2, 3, and 4 right on Boeing Model 
747-100 series airplanes. Investigation revealed that the power 
switches burned due to an internal failure of the switch and resulted 
in a short circuit to ground.

Description of New Service Information

    Since the issuance of the proposal, the FAA also has reviewed and 
approved Boeing Alert Service Bulletin 747-33A2261, Revision 1, dated 
June 4, 1998, which describes procedures for replacing certain power 
switches with new, improved switches. The improved switches will 
prevent an internal failure of the switch that could result in a short 
circuit between the switch and its ground, thereby reducing the 
potential for fire or smoke. The switches described in the alert 
service bulletin are the switches for the passenger entertainment and/
or passenger service system on the cabin attendant's switch panel at 
doors 1 left, 1 right, 3 left, 3 right, 4 left, and 5 right, and in the 
stairwell and upper deck. The alert service bulletin also describes 
procedures for installing a ground clamp, reterminating the wires in 
the connectors, modifying certain circuit breakers, and performing a 
continuity test on the panel when the modification is complete. 
Accomplishment of the actions specified in Revision 1 of the alert 
service bulletin is intended to adequately address the identified 
unsafe condition.
    The manufacturer has advised that the procedures described in 
Boeing Alert Service Bulletin 747-33A2252, dated August 1, 1996, as 
amended by Boeing Notice of Status Change 747-33A2252 NSC 01, dated 
October 10, 1996 (cited as the appropriate source of service 
information in the proposal), apply only to doors 2 and 4 right and 
will not work for doors 1 and 3 right. Boeing Alert Service Bulletin 
747-33A2261, described previously, specifies procedures that apply to 
doors 1 and 3 right. Boeing Alert Service Bulletin 747-33A2261 adds a 
procedure for modification of certain circuit breakers that is not 
specified by Boeing Alert Service Bulletin 747-33A2252. The final rule 
specifically omits that modification. Therefore, this change of service 
information referenced in the final rule will not increase the scope of 
the AD.
    Additionally, the applicability of the proposed AD referenced 
airplanes listed in Boeing Alert Service Bulletin 747-33A2252; the 
effectivity of that alert service bulletin includes all Model 747-100, 
-200, and -300 series airplanes. However, the applicability of this 
final rule has been revised to specify that it applies only to Model 
747-100, -200, and -300 series airplanes having cabin attendant's 
panels installed at doors 1 and 3 right. The effectivity of the alert 
service bulletin referenced in this final rule (Boeing Alert Service 
Bulletin 747-33A2261) includes Model 747SP series airplanes, as well as 
Model 747-100, -200, and -300 series airplanes. However, to include 
Model 747SP series airplanes in this final rule would require the 
issuance of a supplemental notice of proposed rulemaking to reopen the 
public comment period. To delay this final rule would be inappropriate, 
since the FAA has determined that an unsafe condition exists and the 
required actions must be accomplished to ensure continued safety. 
However, the FAA may consider additional rulemaking to address the 
identified unsafe condition on Model 747SP series airplanes.

Comments to the NPRM

    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 Proposal

    Several commenters support the proposed rule.

Request To Withdraw the Proposal

    One commenter questions why the replacement action specified by the 
proposal should be mandatory. This commenter reports that it has seen 
no instances of short circuiting of the cabin attendant's panel 
switches at door 1 or 3 right. The commenter states that Boeing's 
review of the switches at these doors revealed no problems.
    The FAA infers that the commenter requests that the proposed AD be 
withdrawn as unnecessary. The FAA does not concur. The manufacturer has 
reported an incident of burned switches found behind the attendant's 
panel at door 3 right, and several instances of problems with switches 
at other panels within the Model 747 fleet. Failure of the subject 
switches could cause short circuiting and result in fire and smoke 
aboard the airplane. Consequently, the FAA has determined that AD 
action is

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necessary to correct this unsafe condition.

Request To Extend the Compliance Time

    Several commenters request that the compliance time be extended 
beyond the proposed 10 months; the commenters suggest various 
compliance times ranging up to 2 years. The commenters' various reasons 
for extending the compliance time are explained below.
    <bullet> Several commenters question whether required parts will be 
available in a timely manner.
    <bullet> Other commenters request an extended compliance time 
because of the anticipated lead time and the time required for 
accomplishment of the actions on a large fleet. One commenter adds that 
a compliance time coinciding with the normal ``C'' check would reduce 
the significant service disruption that would be caused by a 10-month 
compliance time.
    The FAA concurs with the request to extend the compliance time. In 
light of the information presented, the FAA finds that such an 
extension will allow the modification to be performed on this large 
fleet with minimal effect on the maintenance schedule and no adverse 
effect on safety. Paragraphs (a) and (b) of the final rule have been 
revised to specify a compliance time of 14 months.
    Operators should note that, since issuance of the proposal, the 
manufacturer has issued a new alert service bulletin (described 
previously) and has made available the required parts. Therefore, lack 
of appropriate service information or required parts will no longer 
present a problem for operators to comply with the AD in a timely 
manner.

Request To Revise Cost Estimate

    One commenter states that the cost to be incurred by the actions 
required by this AD will greatly exceed the cost as stated in the 
proposal. The commenter states that all of its comments made in 
response to related AD 97-08-05, amendment 39-9993 (62 FR 17534, April 
10, 1997), which concerns panels at doors 2 and 4 right, apply equally 
to this AD, which concerns similar panels at doors 1 and 3 right. In a 
letter dated January 30, 1997, responsive to AD 97-08-05, the commenter 
had stated that the cost associated with rebuilding the panels at doors 
2 and 4 was $41,500 per airplane.
    The FAA infers that the commenter requests that the cost estimate 
be revised in the final rule. The FAA does not concur. The cost 
estimate described in this AD included consideration of several 
comments, including those submitted by this commenter, in response to 
AD 97-08-05. Because the commenter provided no justification for its 
objection to the cost figures, and because no other commenter took 
issue with the costs described in the proposed rule, the FAA considers 
that the cost estimate is accurate.

Explanation of Editorial Change to Rule

    Paragraph (b) of the proposal stated that installation of a certain 
``cabin attendant's panel'' would be prohibited. However, reference to 
a switch in a cabin attendant's panel was inadvertently omitted in the 
proposal. The final rule has been revised to refer to ``a switch in a 
cabin attendant's panel'' having a certain part number.

Differences Between the AD and the Alert Service Bulletin

    Boeing Alert Service Bulletin 747-33A2261 describes additional 
procedures for certain airplanes for modification of certain circuit 
breakers. The FAA has determined that, while operators of those 
airplanes may accomplish this modification, the action as proposed 
(replacement of the switches) is adequate to address the identified 
unsafe condition. The AD therefore will not require modification of the 
circuit breakers.

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 described 
previously. 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 648 Boeing Model 747-100, -200, and -300 
series airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 167 airplanes of U.S. registry will be affected by this 
AD.
    It will take approximately 10 work hours per airplane to accomplish 
the required switch replacement, at an average labor rate of $60 per 
work hour. Required parts will cost approximately $2,600 per airplane 
($1,300 per panel). Based on these figures, the cost impact of the 
switch replacement required by this AD on U.S. operators is estimated 
to be $534,400, or $3,200 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:

98-20-37  Boeing: Amendment 39-10804. Docket 97-NM-85-AD.

    Applicability: Model 747-100, -200, and -300 series airplanes; 
having cabin attendant's panels installed at doors 1 and 3 right; 
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

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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 the installation and use of switches in the cabin 
attendant's panels at doors 1 right and 3 right that could short 
circuit when they fail, and consequently cause fire and smoke aboard 
the airplane, accomplish the following:
    (a) Within 14 months after the effective date of this AD, 
replace the passenger entertainment switches and the passenger 
service system power switches, as applicable, in the cabin 
attendant's panels located at doors 1 right and 3 right, with new, 
improved switches, in accordance with Boeing Alert Service Bulletin 
747-33A2261, Revision 1, dated June 4, 1998.
    (b) As of 14 months after the effective date of this AD, no 
person shall install at doors 1 right and 3 right of any airplane a 
switch in a cabin attendant's panel having a part number identified 
in the ``Old Switch'' column of any table contained in Boeing Alert 
Service Bulletin 747-33A2261, Revision 1, dated June 4, 1998.
    (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, 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.

    (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.
    (e) The replacement shall be done in accordance with Boeing 
Alert Service Bulletin 747-33A2261, Revision 1, dated June 4, 1998. 
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.
    (f) This amendment becomes effective on November 5, 1998.

    Issued in Renton, Washington, on September 22, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-25952 Filed 9-30-98; 8:45 am]
BILLING CODE 4910-13-U 10

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