[Federal Register Volume 62, Number 104 (Friday, May 30, 1997)]
[Proposed Rules]
[Pages 29306-29307]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-14184]


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 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
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  Federal Register / Vol. 62, No. 104 / Friday, May 30, 1997 / Proposed 
Rules  

[[Page 29306]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-85-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 747-100, -
200, and -300 series airplanes. This proposal would require the 
replacement of certain switches located in the cabin attendant's panel 
at doors 1 and 3 right with new, improved switches. This proposal 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 the proposed 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: Comments must be received by July 11, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 97-NM-85-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

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:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 97-NM-85-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules 
Docket No. 97-NM-85-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received several reports indicating that fires and 
smoke have occurred aboard Model 747-100 series airplanes behind the 
cabin attendant's panel at doors 2 right, 3 right, and 4 right. These 
incidents, reported by six operators, occurred during flight or after 
landing.
    Investigation revealed that the fires were the result of internal 
failures in switches S4 and/or S5, or switches S7 and S8 at door 4 
right, and equivalent switches at the other doors. These failures 
caused a short circuit between the switch and its ground.
    Equivalent switches are also located in the cabin attendant's panel 
at door 1 right although no incidents of fire from the failure of those 
switches have been reported. In addition, switches of this type are 
found on Model 747-200 and -300 series airplanes.
    The installation and use of a switch that could short circuit when 
it fails, if not corrected, could result in fire and smoke aboard the 
airplane.

Related AD Actions

    On April 2, 1997, the FAA issued AD 97-08-05, amendment 39-9993 (62 
FR 17534, April 10, 1997), 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 doors 2 right and 4 right 
with new improved switches. That AD was 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 that 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.
    When that AD was issued, the FAA, in response to a comment during 
the making of that rule, acknowledged that certain switches at doors 1 
right and 3 right also are subject to the same unsafe condition as the 
switches at doors 2 and 4. The FAA, however, determined that delaying 
the issuance of that AD in order to include those switches was not 
appropriate because of the urgency associated with correcting the 
unsafe condition at doors 2 right and 4 right, and in light of the time 
that had elapsed since the original proposed rule had been issued. The 
FAA pointed out, however, that it was considering additional rulemaking 
action to address doors 1 right and 3 right. This proposed action is 
the result of the FAA's review.

[[Page 29307]]

Explanation of Relevant Service Information

    The FAA has reviewed and approved 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. That alert 
service bulletin describes procedures for the replacement of switches 
S4 and/or S5, or switches S7 and S8 that are installed in the cabin 
attendant's panel at door 4 right with new, improved switches. Those 
same procedures can be used (and are just as effective) for replacing 
the equivalent switches installed in the cabin attendant's panel at 
doors 1 right and 3 right.
    In the event that an improved switch fails internally, there will 
be no short circuit between the switch and its ground; therefore, the 
potential for fire or smoke to occur is reduced.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require replacement of the switches at doors 1 right 
and 3 right that are equivalent to the S4 and/or S5, or S7 and S8 
switches installed in the cabin attendant's panel at door 4 right. 
These switches would be replaced with new, improved switches. The 
actions would be required to be accomplished in accordance with the 
Boeing alert service bulletin, as revised, described previously.

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 would be 
affected by this proposed AD. It would take approximately 10 work hours 
per airplane to accomplish the proposed actions, at an average labor 
rate of $60 per work hour. Required parts would cost approximately 
$2,600 per airplane ($1,300 per panel). Based on these figures, the 
cost impact of the proposed 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 proposed 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 proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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:

Boeing: Docket 97-NM-85-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 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 10 months after the effective date of this AD, 
replace the switches located at doors 1 right and 3 right that are 
equivalent to switches S4 and/or S5, or S7 and S8 installed in the 
cabin attendant's panel at door 4 right with new, improved switches, 
in accordance with 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.

    Note 2: Although the procedures in this alert service bulletin, 
as revised, pertain to the replacement of the switches located at 
door 4 right, these procedures can be used (and are just as 
effective) for replacing the equivalent switches located at doors 1 
right and 3 right.

    (b) As of 10 months from the effective date of this AD, no 
person shall install at doors 1 right and 3 right of any airplane a 
cabin attendant's panel having a part number identified in the ``Old 
Switch '' column of any table contained in Boeing Alert Service 
Bulletin 747-33A2252, 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.

    Issued in Renton, Washington, on May 23, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-14184 Filed 5-29-97; 8:45 am]
BILLING CODE 4910-13-P