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

[Federal Register Volume 62, Number 69 (Thursday, April 10, 1997)]
[Rules and Regulations]
[Pages 17534-17536]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-9010]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-239-AD; Amendment 39-9993; AD 97-08-05]
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 replacement of certain switches in the cabin 
attendant's panel at door 4 right and door 2 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 switches that could short circuit 
when they fail, and consequently cause fire and smoke aboard the 
airplane.

DATES: Effective May 15, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 15, 1997.

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 (206) 227-2790; fax (206) 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 as 
a supplemental notice of proposed rulemaking (NPRM) on January 21, 1997 
(62 FR 2981). That action proposed to require removing switches S4 and/
or S5, or switches S7 and S8, that are currently installed on the cabin 
attendant's panel at door 4 right, and the equivalent switches at door 
2 right, and replacing them with new improved switches.
    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

    Two commenters support the proposed rule.

Request To Include a New Requirement for Doors 1 and 3

    One commenter requests that the proposed replacement of the 
switches on the cabin attendant's panel also be accomplished at doors 1 
and 3. The commenter states that doors 1 and 3 have the same switches 
that are subject to the addressed unsafe condition as the switches at 
doors 2 and 4.
    The FAA acknowledges that the switches at doors 1 and 3 are prone 
to failure; however, at this time, the FAA has received no reports of 
fire and smoke at those locations. The FAA points out that adding a new 
requirement to the proposed AD would require public comment before 
adopting a final rule, hence a second supplemental NPRM. The FAA has 
considered the degree of urgency associated with addressing the 
identified unsafe condition at doors 2 and 4, and the amount of time 
that has already elapsed since issuance of the original proposed rule. 
In light of these items, the FAA has determined that further delay of 
this final rule action is not appropriate. However, the FAA is 
currently considering issuing a separate rulemaking action to address 
the identified unsafe condition at doors 1 and 3.

Request for an Alternative Method of Compliance

    One commenter requests that the FAA revise paragraph (a) of the 
proposed rule to reference an alternative method of compliance for 
replacing the existing switches with new improved replacement switches. 
The commenter recommends suitable plug-in switches, in lieu of the 
soldered switches, as described in Boeing Alert Service Bulletin 747-
33A2252, dated August 1, 1996 (which is referenced in the proposed AD 
as the appropriate source of service information). The commenter states 
that soldered switches add

[[Page 17535]]

considerable complexity and cost to the replacement, which prevents 
accomplishment of the replacement on the line. The commenter notes that 
it has requested Boeing revise the referenced alert service bulletin to 
specify a suitable plug-in switch.
    The FAA does not concur. The FAA does not consider it appropriate 
to include various provisions in an AD applicable to a single 
operator's unique use of an affected airplane. Paragraph (c) of this AD 
contains a provision for requesting approval of an alternative method 
of compliance to address these types of unique circumstances. The FAA 
acknowledges that a design solution that utilizes plug-in switches may 
cost less and may be less complex; however, the FAA does not mandate a 
design solution based on those criteria alone. Further, the FAA is 
unaware of a revision to the referenced alert service bulletin.

Request To Revise the Cost Estimate

    One commenter questions the FAA's cost and work hour estimate in 
the preamble of the proposal. The commenter states that the estimated 
per airplane cost of $1,112, presented in the cost impact information 
in the preamble to the proposal, is too low. This commenter suggests 
that the required replacement would take approximately 10 work hours 
per airplane and would cost approximately $1,300 per panel (2 panels 
per airplane). Upon further review, the FAA concurs that the number of 
work hours and cost of required parts is higher than approximated 
previously. The FAA has revised the cost impact information, below, to 
include this updated information.

New Notice of Status Change

    Since issuance of the supplemental NPRM, Boeing has issued Notice 
of Status Change (NSC) 747-33A2252 NSC 01, dated October 10, 1996, 
which amends Boeing Alert Service Bulletin 747-33A2252, dated August 1, 
1996. This NSC removes airplanes that have been converted to special 
freighters from the effectivity listing of the alert service bulletin 
and makes certain editorial changes. The FAA has revised the final rule 
to reference this NSC as an additional source of service information.

New ``Note 2''

    The FAA has revised the final rule to include a new NOTE 2 to 
clarify that, although the procedures in Boeing Alert Service Bulletin 
747-33A2252, dated August 1, 1996, address replacing only the switches 
located at door 4, they can be used just as effectively for replacing 
the switches located at door 2. The FAA mentioned this clarification in 
the Requirements of the Revised Proposed Rule Section in the preamble 
of the supplemental NPRM.

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 
significantly 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. Of this 
number, the FAA estimates that 167 airplanes of U.S. registry will be 
affected by this AD.
    The required replacement of the switches will take approximately 10 
work hours per airplane to accomplish, at an average labor rate of $60 
per work hour. Required parts will cost approximately $1,300 per panel 
(2 panels per airplane). Based on these figures, the cost impact of the 
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:

97-08-05  Boeing: Amendment 39-9993. Docket 96-NM-239-AD.

    Applicability: Model 747-100, -200, and -300 series airplanes; 
as listed in Boeing Alert Service Bulletin 747-33A2252, dated August 
1, 1996, as revised by Boeing Notice of Status Change 747-33A2252 
NSC 01, dated October 10, 1996; 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 (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 panel that could short circuit when they fail, and 
consequently cause fire and smoke aboard the airplane, accomplish 
the following:
    (a) Within 10 months after the effective date of this AD, remove 
switches S4 and/or S5, or switches S7 and S8, that are installed in 
the cabin attendant's panel at door 4 right, and the equivalent 
switches at door 2 right, and replace them with new switches in 
accordance with the procedures specified in Boeing Alert Service 
Bulletin 747-33A2252, dated August 1, 1996, as revised by Boeing 
Notice of Status Change 747-33A2252 NSC 01, dated October 10, 1996.


[[Page 17536]]


    Note 2: Although the procedures in Boeing Alert Service Bulletin 
747-33A2252, dated August 1, 1996, as revised by Boeing Notice of 
Status Change 747-33A2252 NSC 01, dated October 10, 1996, address 
replacing only the switches located at door 4, they can be used just 
as effectively for replacing the switches located at door 2.

    (b) As of the effective date of this AD, no person shall install 
at door 2 right or at door 4 right of any airplane an attendant's 
panel having switch part numbers identified in the ``Old Switch'' 
column of any table contained in Boeing Alert Service Bulletin 747-
33A2252, dated August 1, 1996, as revised by Boeing Notice of Status 
Change 747-33A2252 NSC 01, dated October 10, 1996.
    (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 3: 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 747-33A2252, dated August 1, 1996, as revised 
by Boeing Notice of Status Change 747-33A2252 NSC 01, dated October 
10, 1996. 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 May 15, 1997.

    Issued in Renton, Washington, on April 2, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-9010 Filed 4-9-97; 8:45 am]
BILLING CODE 4910-13-U

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