E7-22724. Airworthiness Directives; Boeing Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes

AGENCY:

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

ACTION:

Final rule; request for comments.

Summary:

The FAA is superseding an existing airworthiness directive (AD) that applies to all Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. The existing AD currently requires repetitive detailed inspections for damage of the electrical wire and sleeve that run to the fuel boost pump through a conduit in the fuel tank, and arcing damage of the conduit and signs of fuel leakage into the conduit; replacement of the sleeve with a new, smaller-diameter sleeve; and related investigative and corrective actions, as applicable. This new AD reduces the inspection threshold for certain airplanes. This AD results from a report of a fuel tank explosion on a Model 727-200F airplane on the ground, and a report of chafed wires and a damaged power cable sleeve of a fuel boost pump discovered during an inspection on a Model 737-300 airplane. (The fuel boost pump installation on certain Model 737 airplanes is almost identical to the installation on Model 727 airplanes.) We are issuing this AD to detect and correct chafing of the fuel boost pump electrical wiring and leakage of fuel into the conduit, and to prevent electrical arcing between the wiring and the surrounding conduit, which could result in arc-through of the conduit, and consequent fire or explosion of the fuel tank.

DATES:

This AD becomes effective December 6, 2007.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of December 6, 2007.

On June 6, 2007 (72 FR 28597, May 22, 2007), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 737-28A1263, Revision 1, dated March 19, 2007.

We must receive any comments on this AD by January 22, 2008.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Suzanne Lucier, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Discussion

On May 2, 2007, we issued AD 2007-11-07, amendment 39-15064 (72 FR 28597, May 22, 2007). (A correction of that AD was published in the Federal Register on August 21, 2007 (72 FR 46559).) That AD applies to all Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. That AD requires repetitive detailed inspections for damage of the electrical wire and sleeve that run to the fuel boost pump through a conduit in the fuel tank, and arcing damage of the conduit and signs of fuel leakage into the conduit; replacement of the sleeve with a new, smaller-diameter sleeve; and related investigative and corrective actions, as applicable. That AD resulted from a report of a fuel tank explosion on a Model 727-200F airplane on the ground, and a report of chafed wires and a damaged power cable sleeve of a fuel boost pump discovered during an inspection on a Model 737-300 airplane. The actions specified in that AD are intended to detect and correct chafing of the fuel boost pump electrical wiring and leakage of fuel into the conduit, and to prevent electrical arcing between the wiring and the surrounding conduit, which could result in arc-through of the conduit, and consequent fire or explosion of the fuel tank.

Actions Since AD Was Issued

Since we issued AD 2007-11-07, we were contacted by an operator who misinterpreted the compliance threshold in a way that was not intended. Therefore, we are issuing this new AD to restate certain compliance thresholds in a new way in order to avoid misinterpretation and to ensure continued operational safety of these airplanes. To do so, we have based certain compliance thresholds on previous accomplishment of any revision of Boeing Alert Service Bulletin 737-28A1120 identified in paragraph (i)(1), (i)(2), (i)(3), or (i)(4) of This AD. These revisions of Boeing Alert Service Bulletin 737-28A1120 were previously mandated by AD 99-21-15, amendment 39-11360 (64 FR 54763, October 8, 1999) and the two ADs it superseded. AD 99-21-15 was superseded by AD 2007-11-07; therefore, we have not restated the requirements of AD 99-21-15 in this new AD.

Related Rulemaking

On May 1, 2007, we issued AD 2007-11-08, amendment 39-15065 (72 FR 28594, May 22, 2007), which applies to all Boeing Model 727 airplanes. AD 2007-11-08 requires repetitive inspections for damage of the electrical wire and sleeve that run to the fuel boost pump though a conduit in the fuel tank, and arcing damage of the conduit and signs of fuel leakage into the conduit; applicable investigative and corrective actions; and a repetitive engine fuel suction feed operational test. That AD resulted from reports of a fuel tank explosion on a Model 727-200F airplane on the ground; and of chafed wires and a damaged power cable sleeve of a fuel boost pump that were discovered during an inspection required by an existing AD on a Model 737-300 airplane. We issued that AD to detect and correct chafing of the fuel boost pump electrical wiring and leakage of fuel into the conduit, and to prevent electrical arcing between the wiring and the surrounding conduit, which could result in arc-through of the conduit, and consequent fire or explosion of the fuel tank.

Relevant Service Information

Since we issued AD 2007-11-07, Boeing has issued Service Bulletin 737-28A1263, Revision 2, dated August 10, 2007. We referred to Boeing Alert Service Bulletin 737-28A1263, Revision 1, dated March 19, 2007, as the appropriate source of service information for accomplishing certain actions in AD 2007-11-07. The procedures in Revision 2 of the service bulletin are essentially the same as those in Revision 1, with several editorial changes such as a revised e-mail address, and the addition of references to AD 2007-11-07. Revision 2 also incorporates alternative methods of compliance (AMOCs) previously approved for AD 2007-11-07.

FAA's Determination and Requirements of This AD

The unsafe condition described previously is likely to exist or develop on other airplanes of the same type design. For this reason, we are issuing this AD to supersede AD 2007-11-07. This new AD retains certain requirements of the existing AD. This AD also reduces the compliance threshold for certain airplanes.

Interim Action

We consider this AD interim action. If final action is later identified, we might consider further rulemaking then.

FAA's Determination of the Effective Date

An unsafe condition exists that requires the immediate adoption of this AD; therefore, providing notice and opportunity for public comment before the AD is issued is impracticable, and good cause exists to make this AD effective in less than 30 days.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2007-0211; Directorate Identifier 2007-NM-221-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD.

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 the 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. 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.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

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

§ 39.13

[Amended]

2. The Federal Aviation Administration (FAA) amends § 39.13 by removing amendment 39-15064 ( 72 FR 28597, May 22, 2007), corrected at 72 FR 46559, August 21, 2007, and adding the following new airworthiness directive (AD):

2007-24-02 Boeing: Docket No. FAA-2007-0211; Directorate Identifier 2007-NM-221-AD; Amendment 39-15268.

Effective Date

(a) This AD becomes effective December 6, 2007.

Affected ADs

(b) This AD supersedes AD 2007-11-07.

Applicability

(c) This AD applies to all Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category.

Unsafe Condition

(d) This AD results from a report of a fuel tank explosion on a Model 727-200F airplane on the ground, and a report of chafed wires and a damaged power cable sleeve of a fuel boost pump discovered during an inspection on a Model 737-300 airplane. (The fuel boost pump installation on certain Model 737 airplanes is almost identical to the installation on Model 727 airplanes.) We are issuing this AD to detect and correct chafing of the fuel boost pump electrical wiring and leakage of fuel into the conduit, and to prevent electrical arcing between the wiring and the surrounding conduit, which could result in arc-through of the conduit, and consequent fire or explosion of the fuel tank.

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.

Certain Requirements of AD 2007-11-07

Inspection and Related Investigative and Corrective Actions

(f) At the applicable time specified by paragraph (f)(1) or (f)(2) of this AD: Do a detailed inspection for damage of the sleeve and electrical wire of the fuel boost pump; and, before further flight, install a new, smaller-diameter sleeve, and do related investigative and corrective actions, as applicable; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-28A1263, Revision 1, dated March 19, 2007; or Boeing Service Bulletin 737-28A1263, Revision 2, dated August 10, 2007. After the effective date of this AD, Revision 2 must be used. Thereafter, repeat the detailed inspection at intervals not to exceed 15,000 flight hours.

(1) For Model 737-100, -200, -300, -400, and -500 series airplanes: At the time specified in paragraph (i) or (j) of this AD, as applicable.

(2) For Model 737-200C series airplanes: Within 120 days after June 6, 2007 (the effective date of AD 2007-11-07), or within 5,000 flight hours after the last inspection or repair done in accordance with any version of Boeing Alert Service Bulletin 737-28-1120, whichever occurs later.

Inspection Report and Disposition of Damaged Parts

(g) At the applicable time specified in paragraph (g)(1) or (g)(2) of this AD: Submit a report of the findings (both positive and negative) of any inspection required by paragraph (f) of this AD and send any damaged parts to the manufacturer, as described in Boeing Alert Service Bulletin 737-28A1263, Revision 1, dated March 19, 2007. The report must include the inspection results, a description of any discrepancies found, the airplane serial number, and the number of landings and flight hours on the airplane. Under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements contained in this AD and has assigned OMB Control Number 2120-0056.

(1) For any inspection done on or after June 6, 2007: Submit the report within 30 days after the inspection.

(2) For any inspection done before June 6, 2007: Submit the report within 30 days after June 6, 2007.

Credit for Actions Done Using Previous Service Information

(h) Actions accomplished before June 6, 2007, in accordance with Boeing Service Bulletin 737-28A1263, dated February 19, 2007, are considered acceptable for compliance with the corresponding actions specified in this AD.

New Requirements of This AD

Previously Required Inspection at New Compliance Times

(i) For Model 737-100, -200, -300, -400, and -500 series airplanes having line numbers 1 through 3072 inclusive: Within 120 days after the effective date of this AD, or within 5,000 flight hours after the last inspection or repair done in accordance with any service bulletin listed in paragraph (i)(1), (i)(2), (i)(3), or (i)(4) of this AD, whichever occurs later, do the actions specified in paragraph (f) of this AD.

(1) Boeing Alert Service Bulletin 737-28A1120, dated April 24, 1998, as revised by Notices of Status Change NSC 01, dated May 7, 1998, NSC 02, dated May 8, 1998, and NSC 03, dated May 9, 1998.

(2) Boeing Alert Service Bulletin 737-28A1120, Revision 1, dated May 28, 1998.

(3) Boeing Alert Service Bulletin 737-28A1120, Revision 2, dated November 26, 1998.

(4) Boeing Service Bulletin 737-28A1120, Revision 3, dated April 26, 2001.

(j) For Model 737-100, -200, -300, -400, and -500 series airplanes having line numbers 3073 and subsequent: At the applicable time specified in paragraph (j)(1) or (j)(2) of this AD, do the actions specified in paragraph (f) of this AD.

(1) For airplanes on which the inspection or repair specified in any service bulletin listed in paragraph (i)(1), (i)(2), (i)(3), or (i)(4) of this AD, has been done as of the effective date of this AD: Within 120 days after the effective date of this AD or 5,000 flight hours after the last inspection done in accordance with any service bulletin listed in paragraph (i)(1), (i)(2), (i)(3), or (i)(4) of this AD, whichever occurs later.

(2) For airplanes on which the inspection or repair specified in any service bulletin listed in paragraph (i)(1), (i)(2), (i)(3), or (i)(4) of this AD, has not been done as of the effective date of this AD: Before the accumulation of 5,000 total flight hours, or within 120 days after the effective date of this AD, whichever occurs later.

Inspection Report and Disposition of Damaged Parts

(k) For Model 737-100, -200, -300, -400, and -500 series airplanes: At the applicable time specified in paragraph (k)(1) or (k)(2) of this AD, submit a report of the findings (both positive and negative) of any inspection required by paragraph (i) or (j) of this AD and send any damaged parts to the manufacturer, as described in Boeing Service Bulletin 737-28A1263, Revision 2, dated August 10, 2007. The report must include the inspection results, a description of any discrepancies found, the airplane serial number, and the number of landings and flight hours on the airplane. Under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements contained in this AD and has assigned OMB Control Number 2120-0056.

(1) For any inspection done after the effective date of this AD: Submit the report within 30 days after the inspection.

(2) For any inspection done before the effective date of this AD: Submit the report within 30 days after the effective date of this AD.

Alternative Methods of Compliance (AMOCs)

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

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

(3) AMOCs approved previously in accordance with AD 99-21-15, amendment 39-11360, and AD 2007-11-07 are approved as AMOCs for the corresponding provisions of this AD.

Material Incorporated by Reference

(m) You must use applicable Boeing service bulletins specified in Table 1 of this AD to perform the actions that are required by this AD, unless the AD specifies otherwise.

Table 1.—All Material Incorporated by Reference

Service Bulletin	Revision level	Date
Boeing Alert Service Bulletin 737-28A1263	1	March 19, 2007.
Boeing Service Bulletin 737-28A1263	2	August 10, 2007.

(1) The Director of the Federal Register approved the incorporation by reference of Boeing Service Bulletin 737-28A1263, Revision 2, dated August 10, 2007, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) On June 6, 2007 (72 FR 28597, May 22, 2007), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 737-28A1263, Revision 1, dated March 19, 2007.

(3) 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 FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Issued in Renton, Washington, on November 8, 2007.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.