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

Document Details

Information about this document as published in the Federal Register.

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AGENCY:

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

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ACTION:

Final rule; request for comments.

SUMMARY:

The FAA is superseding an existing airworthiness directive (AD) that applies to all Model 737-100, -200, -300, -400, and -500 series airplanes. The existing AD currently requires repetitive detailed inspections for damage of the electrical wire and sleeve that run through a conduit in the fuel tank to the fuel boost pump, and related investigative and corrective actions; as applicable. This new AD removes certain inspection requirements. This new AD adds 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 AD also adds airplanes to the applicability. Accomplishment of the initial new inspection and the sleeve installation terminates the requirements of the existing AD. This new 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. 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 June 6, 2007.

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

On November 12, 1999 (64 FR 54763, October 8, 1999), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 737-28A1120, Revision 2, dated November 26, 1998.

On October 15, 1998 (63 FR 52152, September 30, 1998), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 737-28A1120, Revision 1, dated May 28, 1998.

On June 29, 1998 (63 FR 34271, June 24, 1998), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 737-28A1120, dated April 24, 1998, as revised by Notice of Status Change NSC 01, dated May 7, 1998, Notice of Status Change NSC 02, dated May 8, 1998, and Notice of Status Change NSC 03, dated May 9, 1998.

We must receive any comments on this AD by July 23, 2007.

ADDRESSES:

Use one of the following addresses to submit comments on this AD.

  • DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
  • Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
  • Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590.
  • Fax: (202) 493-2251.
  • Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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

You may examine the contents of 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., Room PL-401, Washington, DC. This docket number is FAA-2007-28253; the directorate identifier for this docket is 2007-NM-031-AD.

Start Further Info

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 (425) 917-6438; fax (425) 917-6590.

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SUPPLEMENTARY INFORMATION:

Discussion

On September 29, 1999, we issued AD 99-21-15, amendment 39-11360 (64 FR 54763, October 8, 1999). That AD applies to certain Boeing Model 737-100, -200, -300, -400, and -500 series airplanes. That AD requires repetitive detailed inspections for damage of the electrical wire and sleeve that run through a conduit in the fuel tank to the fuel boost pump, and related investigative and corrective actions, as applicable. That AD resulted from reports of severe wear of the fuel boost pump wiring due to chafing between the wiring and the surrounding conduit inside the fuel tank, pin-hole-sized holes in the conduit that appear to be the result of arc-through of the conduit, and exposure of the main tank boost pump wire conductor inside a conduit and signs of arcing to the wall of the conduit. The actions specified in that AD are intended to detect and correct chafing and prevent electrical arcing between the fuel boost pump electrical 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 that AD, we received a report that a fuel tank explosion occurred on a Model 727-200F airplane on the ground. Investigation revealed evidence of arcing in the metal conduit that carries power wires from the front spar through the fuel tank to the dry bay of the #1 aft fuel boost pump. In a separate incident, we received a report from Boeing indicating that chafed wires and a damaged power cable sleeve of a fuel boost pump were discovered during a repetitive inspection of the power cable and sleeve of a Model 737-300 airplane; that inspection was done at approximately 21,000 flight hours rather than the repetitive interval of 30,000 flight hours specified by the existing AD. The fuel boost pump installation on certain Model 737 airplanes is almost identical to the installation on Model 727 airplanes.

We have also determined that Model 737-200C series airplanes are also subject to the unsafe condition identified in AD 99-21-15.

Other Relevant Rulemaking

Operators should note that we are considering issuing a separate AD to address the identified unsafe condition as it relates to Model 727 airplanes.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 737-28A1263, Revision 1, dated March 19, 2007. This service bulletin differs from the service information cited in AD 99-21-15 in the following ways. The alert service bulletin describes procedures for performing new 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; replacing the sleeve with a new, smaller-diameter sleeve; performing related investigative and corrective actions, as applicable; and reporting inspection results and returning damaged parts to the manufacturer. The repetitive interval for the detailed inspections is 15,000 flight hours (rather than 30,000 flight hours, Start Printed Page 28599as required by AD 99-21-15). Related investigative and corrective actions include replacing, with BMS 13-60T09C03G018 wire, any wire that is damaged or has any part number other than BMS 13-60T09C03G018 or BMS 13-60T12C03G018; doing leak testing of the conduit if signs of fuel are discovered on the wire or sleeve during any inspection; and repairing any damaged conduit or replacing it with a new conduit.

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 99-21-15. This new AD retains certain requirements of the existing AD. This AD also requires accomplishing the actions specified in the alert service bulletin described previously.

Changes to Existing AD

Instead of restating all of the corrective actions specified in AD 99-21-15, that is, paragraphs (h), (i), (j), and (k), we simplified these requirements by consolidating them into paragraph (j) in this AD. We have verified that all of the information of paragraphs (h), (i), (j), and (k) of AD 99-21-15 is contained in the service bulletin references identified in paragraph (j) of this AD.

Clarification of Applicability

The applicability of AD 99-21-15 did not specifically list Model 737-200C series airplanes. Likewise, the service information (Boeing Service Bulletin 737-28A1120, original version, Revision 1, and Revision 2) cited in that AD did not specifically identify Model 737-200C series airplanes in the effectivity, although Revision 3 did identify them. Because the unsafe condition could occur on those airplanes, this AD adds them to the applicability to ensure that the actions required by this AD are accomplished on all affected airplanes. We recognize that some of these airplanes might have already been inspected as specified in the existing AD. In order to give credit for work accomplished on these airplanes, this AD adds a compliance time for the initial inspection relative to the date of the most recent inspection done in accordance with Service Bulletin 737-28A1120.

Interim Action

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

Explanation of Compliance Time

The compliance time for the new inspection in this AD is 120 days. Based on the large number of affected U.S.-registered airplanes and the amount of time required to accomplish the required actions, including corrective actions, we consider that this compliance time is necessary to avoid unnecessarily disrupting flight schedules.

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 that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any relevant written data, views, or arguments regarding this AD. Send your comments to an address listed in the ADDRESSES section. Include “Docket No. FAA-2007-28253; Directorate Identifier 2007-NM-031-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD that might suggest a need to modify it.

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the 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 DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

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.

Start List of Subjects

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 part 39 of the Federal Aviation Regulations (

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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 removing amendment 39-11360 (

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2007-11-07 Boeing: Docket No. FAA-2007-28253; Directorate Identifier 2007-NM-031-AD; Amendment 39-15064.

Effective Date

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

Affected ADs

(b) This AD supersedes AD 99-21-15.

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.

Restatement of Certain Requirements of AD 99-21-15

Certain Inspections Required by AD 98-11-52

(f) For Model 737-100, -200, -300, -400, and -500 series airplanes: Prior to the accumulation of 30,000 total flight hours or within 45 days after June 29, 1998 (the effective date of AD 98-11-52, amendment 39-10611, which was superseded by AD 98-19-09), whichever occurs later, remove the fuel boost pump wiring from the in-tank conduit for the aft boost pumps in main tanks numbers 1 and 2, and the center tank left and right boost pumps, and perform a detailed visual inspection to detect damage of the wiring, in accordance with the procedures specified in 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; Revision 1, dated May 28, 1998; or Revision 2, dated November 26, 1998.

Inspections Required by AD 98-19-09

(g) For Model 737-100, -200, -300, -400, and -500 series airplanes that have accumulated 20,000 or more total flight hours and less than 30,000 total flight hours as of October 15, 1998 (the effective date of AD 98-19-09, amendment 39-10751, which was superseded by AD 99-21-15): Within 60 days after October 15, 1998, remove the fuel boost pump wiring from the in-tank conduit for the aft boost pumps in main tanks numbers 1 and 2, and the center tank left and right boost pumps, and perform a detailed visual inspection to detect damage of the wiring; in accordance with the procedures specified in 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; Revision 1, dated May 28, 1998; or Revision 2, dated November 26, 1998.

Inspections Required by AD 99-21-15

(h) For Model 737-100, -200, -300, -400, and -500 series airplanes: Remove the fuel boost pump wiring from the in-tank conduit for the aft boost pumps in main tanks numbers 1 and 2, and the center tank left and right boost pumps, and perform a detailed visual inspection to detect damage of the wiring; at the time specified in paragraph (h)(1) or (h)(2) of this AD, as applicable. Perform these actions in accordance with the procedures specified in 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; Revision 1, dated May 28, 1998; or Revision 2, dated November 26, 1998.

(1) For airplanes having line numbers 1 through 3072 inclusive that have accumulated less than 20,000 total flight hours as of October 15, 1998: Inspect at the earlier of the times specified in paragraphs (h)(1)(i) and (h)(1)(ii) of this AD.

(i) Prior to the accumulation of 20,000 total flight hours, or within 60 days after November 12, 1999 (the effective date of AD 99-21-15), whichever occurs later.

(ii) Within 24 months after November 12, 1999.

(2) For airplanes having line numbers 3073 and subsequent: Inspect prior to the accumulation of 30,000 total flight hours.

Repetitive Intervals

(i) For Model 737-100, -200, -300, -400, and -500 series airplanes: Repeat the inspection required by paragraph (f), (g), or (h) of this AD, as applicable, at intervals not to exceed 30,000 flight hours after initial accomplishment of the applicable inspection, until the initial inspection, applicable corrective actions, and sleeve installation required by paragraph (k) of this AD have been done.

Corrective Actions

(j) If any discrepancy is found during any inspection required by paragraph (f), (g), (h), or (i) of this AD: Before further flight, repair the discrepancy in accordance with the Accomplishment Instructions of 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; Revision 1, dated May 28, 1998; Revision 2, dated November 26, 1998; or Revision 3, dated April 26, 2001.

New Requirements of This AD

Inspection and Related Investigative and Corrective Actions

(k) At the applicable time specified by paragraph (k)(1) or (k)(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. Thereafter, repeat the detailed inspection at intervals not to exceed 15,000 flight cycles. Accomplishment of the initial inspection, applicable corrective actions, and sleeve installation required by this paragraph terminates the requirements of paragraphs (f), (g), (h), and (i) of this AD.

(1) For Model 737-100, -200, -300, -400, and -500 series airplanes: Within 120 days after the effective date of this AD, or within 5,000 flight hours after the last inspection or repair done as required by paragraph (f), (g), (h), or (i), as applicable, of this AD, whichever occurs later.

(2) For Model 737-200C series airplanes: 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 version of Boeing Alert Service Bulletin 737-28-1120, whichever occurs later.

Inspection Report and Disposition of Damaged Parts

(l) At the applicable time specified in paragraph (l)(1) or (l)(2) of this AD: Submit a report of the findings (both positive and negative) of any inspection required by paragraph (k) 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 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.Start Printed Page 28601

Credit for Actions Done Using Previous Service Information

(m) Actions accomplished before the effective date of this AD 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.

Alternative Methods of Compliance (AMOCs)

(n)(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, are approved as AMOCs for the corresponding provisions of this AD.

Material Incorporated by Reference

(o) 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 BulletinRevision levelDate
Boeing Alert Service Bulletin 737-28A1120, as revised by Notice of Status Change NSC 01, dated May 7, 1998, Notice of Status Change NSC 02, dated May 8, 1998, and Notice of Status Change NSC 03, dated May 9, 1998OriginalApril 24, 1998.
Boeing Alert Service Bulletin 737-28A11201May 28, 1998.
Boeing Alert Service Bulletin 737-28A11202November 26, 1998.
Boeing Service Bulletin 737-28A11203April 26, 2001.
Boeing Alert Service Bulletin 737-28A12631March 19, 2007.

(1) The Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 737-28A1263, Revision 1, dated March 19, 2007; and Boeing Service Bulletin 737-28A1120, Revision 3, dated April 26, 2001; in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) On November 12, 1999 (64 FR 54763, October 8, 1999), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 737-28A1120, Revision 2, dated November 26, 1998.

(3) On October 15, 1998 (63 FR 52152, September 30, 1998), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 737-28A1120, Revision 1, dated May 28, 1998.

(4) On June 29, 1998 (63 FR 34271, June 24, 1998), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 737-28A1120, dated April 24, 1998, as revised by Notice of Status Change NSC 01, dated May 7, 1998, Notice of Status Change NSC 02, dated May 8, 1998, and Notice of Status Change NSC 03, dated May 9, 1998.

(5) 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.

Start Signature

Issued in Renton, Washington, on May 2, 2007.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Supplemental Information

[FR Doc. E7-9801 Filed 5-21-07; 8:45 am]

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