Airworthiness directives: Boeing,

 
CONTENT

[Federal Register: October 1, 1998 (Volume 63, Number 190)]

[Rules and Regulations]

[Page 52587-52589]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr01oc98-5]

[[Page 52587]]

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.

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. 98-25952Filed9-30-98; 8:45 am]

    BILLING CODE 4910-13-U 10