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Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

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AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Final rule.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. This AD requires replacing brackets that hold the P5 panel to the airplane structure, the standby compass bracket assembly, the generator drive and standby power module, and the air conditioning module. This AD also requires, among other actions, inspecting for wire length and for damage of the connectors and the wire bundles, and doing applicable corrective actions if necessary. This AD results from an electrical burning smell in the flight compartment. We are issuing this AD to prevent wire bundles from contacting the overhead dripshield panel and modules in the P5 overhead panel, which could result in electrical arcing and shorting of the electrical connector and consequent loss of several critical systems essential for safe flight.

DATES:

This AD becomes effective June 22, 2006.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of June 22, 2006.

ADDRESSES:

You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC.

Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for service information identified in this AD.

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FOR FURTHER INFORMATION CONTACT:

Binh Tran, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6485; fax (425) 917-6590.

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SUPPLEMENTARY INFORMATION:

Examining the Docket

You may examine the airworthiness directive (AD) docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the street address stated in the ADDRESSES section.

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. That NPRM was published in the Federal Register on April 27, 2005 (70 FR 21689). That NPRM proposed to require replacing brackets that hold the P5 panel to the airplane structure, the standby compass bracket assembly, the generator drive and standby power module, and the air conditioning module. That NPRM also proposed to require, among other actions, inspecting for wire length and for damage of the connectors and the wire bundles, and doing applicable corrective actions if necessary.

New Relevant Service Information

Since the issuance of the NPRM, we have reviewed Revision 2 of Boeing Service Bulletin 737-24A1141, dated December 1, 2005 (Revision 1 of the service bulletin was referenced in the NPRM as the appropriate source of service information for doing certain proposed actions). Revision 2 updates multiple figures to correct typographical errors in the graphics or in the task or flag note tables. Revision 2 also moves a certain group of airplanes from one figure to another. The procedures in Revision 2 are essentially identical to those in Revision 1. No more work is necessary on airplanes changed as shown in Revision 1 of the service bulletin. Therefore, we have revised paragraph (f) of this AD to refer to Revision 2 as the appropriate source of service information for doing the required inspection, replacements, wiring changes, and corrective actions if necessary. We also have revised the applicability to refer to Revision 2 as the appropriate source of service information for determining the affected airplanes. In addition, we have added a new paragraph (g) to the AD (and redesignated subsequent paragraphs) to give operators credit for doing the actions required by paragraph (f) before Start Printed Page 28767the effective date of this AD in accordance with Revision 1.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.

Support for NPRM

AirTran Airways and The Boeing Company support the NRPM.

Requests To Extend Compliance Time

The Air Transport Association (ATA) of America, Inc., on behalf of one of its members (American Airlines), and Continental Airlines request that the compliance time specified in paragraph (f) of the NPRM be extended. Continental Airlines states that a compliance time of 36 months is necessary, because of the large number of work hours specified in Boeing Alert Service Bulletin 737-24A1141, Revision 1, for doing the examination, change, and retermination if necessary. American Airlines states that a compliance time of 48 months is necessary to align with heavy maintenance schedules and to avoid an unnecessary financial burden.

We agree that the compliance time in paragraph (f) of this AD can be extended somewhat. We intended to require the inspection, replacements, wiring change, and retermination if necessary at intervals that would coincide with regularly scheduled maintenance visits for the majority of the affected fleet, when the airplanes would be located at a base where special equipment and trained personnel would be readily available, if necessary. Based on the information supplied by the operators, we have determined that 36 months corresponds more closely to the interval representative of most of the affected operators' heavy maintenance schedules. We have revised paragraph (f) of the AD accordingly. We do not consider that this extension will adversely affect safety.

Request for an Alternative Method of Compliance (AMOC)

The ATA of America, Inc., on behalf of one of its members (Delta Air Lines), states that there are a number of errors in Boeing Alert Service Bulletin 737-24A1141, Revision 1, and requests that we approve corrections made to the service bulletin as an AMOC for the corresponding proposed actions in the NPRM. Delta Air Lines states that other errors have been identified in Boeing Information Notice 69-37319-21-02 IN 02.

We partially agree. We agree with the ATA of America, Inc., and Delta Air Lines that there are several errors in Boeing Alert Service Bulletin 737-24A1141, Revision 1, but do not agree to revise the AD as suggested by them. As discussed previously in “New Relevant Service Information,” we have reviewed Boeing Service Bulletin 737-24A1141, Revision 2, and have revised this AD to refer to that revision as an appropriate source of service information for the actions required by paragraph (f) of this AD.

Request To Refer to Original Issue of Service Bulletin

The ATA of America, Inc., on behalf of one of its members (Delta Air Lines), requests that we refer to the original release of Boeing Component Service Bulletin 69-37319-21-02, dated March 15, 2001, in paragraph (g)(2) of the NPRM (redesignated as paragraph (h)(2) in this AD) as an acceptable means of compliance with the proposed modification, if the modification specified in the original release was done before the effective date of the AD. Delta Air Lines notes that Revision 1 of the component service bulletin, which is cited in paragraph (g)(2) as the appropriate source of service information, states, “No more work is necessary on components changed as shown on the initial release of this service bulletin.”

We do not agree. We have confirmed with The Boeing Company that the statement above in Revision 1 of the component service bulletin is incorrect. More work is necessary on components changed as shown in the original issue of the component service bulletin. The Boeing Company has issued Information Notice 69-37319-21-02 IN 03 to inform operators of this error. Therefore, we have made no change to the AD in this regard.

Request To Verify Parts Availability

Alaska Airlines finds the proposed actions and the 24-month compliance time acceptable provided that the kits for parts for the modification are readily available during that period of time.

From this comment, we infer that Alaska Airlines is requesting that we verify whether parts will be available for doing the modifications within the proposed compliance time. The Boeing Company has informed us that there are sufficient parts available for doing the required modification within the compliance time.

Request To Revise Work Hour Estimate

Continental Airlines requests that the work hour estimates for the replacements, inspections, and modifications in “Costs of Compliance” of the NPRM be aligned with the total task hours specified in Boeing Alert Service Bulletin 737-24A1141, Revision 1. Continental Airlines also points out that the cure time (eight hours) and the time for retermination of connectors are not included in the total task hours in the service bulletin.

We do not agree. The “Costs of Compliance” describes only the direct costs of the actions required by this AD. Based on the best data available, The Boeing Company provided 16 or 18 work hours (depending on airplane configuration) for doing the required inspection, replacements, and wiring changes; provided 2 work hours for doing the required modification of the generator drive and standby power module assembly; and provided 1 work hour for doing the required modification of the air conditioning module assembly. These numbers represent the time necessary to perform only the actions actually required by this AD. We recognize that, in doing the actions required by an AD, operators may incur incidental costs in addition to the direct costs. The cost analysis in AD rulemaking actions, however, typically does not include incidental costs such as the time required to gain access and close up, time necessary for planning, or time necessitated by other administrative actions. Those incidental costs, which may vary significantly among operators, are almost impossible to calculate.

In addition, the economic analysis of an AD is limited to the cost of actions that are actually required. The economic analysis does not consider the costs of conditional actions, such as repairing damaged wire bundles detected during a required inspection. Such conditional repairs would be required—regardless of AD direction—to correct an unsafe condition identified in an airplane and to ensure that the airplane is operated in an airworthy condition, as required by the Federal Aviation Regulations. Therefore, we have made no change to this AD in this regard.

Clarification of Alternative Method of Compliance (AMOC) Paragraph

We have revised this action to clarify the appropriate procedure for notifying the principal inspector before using any approved AMOC on any airplane to which the AMOC applies.

Conclusion

We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting Start Printed Page 28768the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

There are about 740 airplanes of the affected design in the worldwide fleet and 333 affected airplanes on the U.S. register.

For all airplanes, the required inspection, replacements, and wiring change will take about 16 or 18 work hours per airplane (depending on airplane configuration), at an average labor rate of $65 per work hour. Required parts will cost about $10,231 or $11,139 per airplane (depending on the kit). Based on these figures, the estimated cost of the replacements and inspections required by this AD for U.S. operators is between $3,753,243 and $4,098,897, or between $11,271 and $12,309 per airplane.

For certain airplanes, the modification of the generator drive and standby power module assembly will take about 2 work hours per airplane, at an average labor rate of $65 per work hour. The airplane manufacturer states that it will supply required parts to operators at no cost. Based on these figures, the estimated cost of this modification required by this AD is $130 per airplane.

For certain other airplanes, the modification of the air conditioning module assembly will take about 1 work hour per airplane, at an average labor rate of $65 per work hour. The airplane manufacturer states that it will supply required parts to operators at no cost. Based on these figures, the estimated cost of this modification required by this AD is $65 per airplane.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD 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.

For the reasons discussed above, I certify that this AD:

(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.

We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

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List of Subjects in 14 CFR Part 39

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Adoption of the Amendment

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Accordingly, under the authority delegated to me by the Administrator, the FAA amends

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PART 39—AIRWORTHINESS DIRECTIVES

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1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]
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2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

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2006-10-17 Boeing: Amendment 39-14601. Docket No. FAA-2005-21028; Directorate Identifier 2004-NM-238-AD.

Effective Date

(a) This AD becomes effective June 22, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes, certificated in any category; as identified in Boeing Service Bulletin 737-24A1141, Revision 2, dated December 1, 2005.

Unsafe Condition

(d) This AD results from an electrical burning smell in the flight compartment. We are issuing this AD to prevent wire bundles from contacting the overhead dripshield panel and modules in the P5 overhead panel, which could result in electrical arcing and shorting of the electrical connector and consequent loss of several critical systems essential for safe flight.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Inspection/Replacements/Wiring Changes/Corrective Actions

(f) Within 36 months after the effective date of this AD, do the actions in paragraphs (f)(1) through (f)(5) of this AD by accomplishing all the applicable actions specified in the Accomplishment Instructions of Boeing Service Bulletin 737-24A1141, Revision 2, dated December 1, 2005. Any applicable corrective actions must be done before further flight.

(1) Replace the five brackets that hold the P5 panel to the airplane structure with new brackets;

(2) Do a general visual inspection for wire length and damage of the connectors and the wire bundles, and applicable corrective actions;

(3) Make wiring changes;

(4) Replace the standby compass bracket assembly with a new assembly; and

(5) Replace the stud assemblies with new assemblies.

Note 1:

For the purposes of this AD, a general visual inspection is: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

(g) Actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin 737-24A1141, Revision 1, dated December 23, 2004, are acceptable for compliance with the requirements of paragraph (f) of this AD.

Concurrent Requirements

(h) Before or concurrently with the requirements of paragraph (f) of this AD, do the applicable action specified in Table 1 of this AD. Start Printed Page 28769

Table 1.—Concurrent Requirements

For airplanes identified in Boeing Component Service Bulletin—Action
(1) 233A3205-24-01, dated July 26, 2001Modify the generator drive and standby power module assembly in accordance with the Accomplishment Instructions of the service bulletin.
(2) 69-37319-21-02, Revision 1, August 30, 2001Modify the air conditioning module assembly in accordance with the Accomplishment Instructions of the service bulletin.

Alternative Methods of Compliance (AMOCs)

(i)(1) The Manager, Seattle Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

Material Incorporated by Reference

(j) You must use the applicable service information identified in Table 2 of this AD to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of these documents in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Room PL-401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov; or at the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call (202) 741-6030, or go to http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

Table 2.—Material Incorporated by Reference

Service bulletinRevision levelDate
(1) Boeing Component Service Bulletin 233A3205-24-01Original IssueJuly 26, 2001.
(2) Boeing Component Service Bulletin 69-37319-21-021August 30, 2001.
(3) Boeing Service Bulletin 737-24A11412December 1, 2005.
Start Signature

Issued in Renton, Washington, on May 8, 2006.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

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[FR Doc. 06-4595 Filed 5-17-06; 8:45 am]

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