Airworthiness Directives; Boeing Model 737 Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 737 airplanes. This proposed AD would require, for certain airplanes, a one-time detailed inspection for interference between a clamp assembly and the wires behind the P15 refuel panel, and corrective actions if necessary. For certain other airplanes, this proposed AD would require a one-time detailed inspection for discrepancies of the wires behind the P15 refuel panel; and corrective and related investigative actions if necessary. This proposed AD is prompted by evidence of chafed wiring behind the P15 refuel panel and arcing to the back of the P15 refuel panel and adjacent wing structure. We are proposing this AD to detect and correct chafing of the wiring behind the P15 refuel panel, which could lead to arcing and fire with consequent airplane damage and injury to refueling personnel.

DATES:

We must receive comments on this proposed AD by December 20, 2004.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed 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.
• By 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.

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

You can examine the contents of this 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, on the plaza level of the Nassif Building, Washington, DC. This docket number is FAA-2004-19539; the directorate identifier for this docket is 2004-NM-06-AD.

FOR FURTHER INFORMATION CONTACT:

Technical information: Sherry Vevea, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6514; fax (425) 917-6590.

Plain language information: Marcia Walters, marcia.walters@faa.gov.

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

The FAA has implemented new procedures for maintaining AD dockets electronically. As of May 17, 2004, new AD actions are posted on DMS and assigned a docket number. We track each action and assign a corresponding directorate identifier. The DMS AD docket number is in the form “Docket No. FAA-2004-99999.” The Transport Airplane Directorate identifier is in the form “Directorate Identifier 2004-NM-999-AD.” Each DMS AD docket also lists the directorate identifier (“Old Docket Number”) as a cross-reference for searching purposes.

Comments Invited

We invite you to submit any written relevant data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2004-19539; Directorate Identifier 2004-NM-06-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments submitted by the closing date and may amend the proposed AD in light of those comments.

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 proposed 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 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.

We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications that affect you. You can get more information about plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the Docket

You can 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 DMS receives them.

Discussion

We have received reports indicating that operators of two Boeing Model 737-700 series airplanes and one Model 737-300 series airplane were unable to refuel the airplanes automatically due to tripped circuit breakers that couldn't be reset. The operators discovered evidence of chafed wiring due to rubbing of wires against sharp edges and components behind the P15 refuel panel, and signs of arcing to the back of the P15 refuel panel and adjacent wing structure. This condition, if not corrected, could lead to arcing and fire with consequent airplane damage and injury to refueling personnel.

Relevant Service Information

We have reviewed Boeing Special Attention Service Bulletin 737-28-1193, dated April 24, 2003 (for Model 737-100, -200, -200C, -300, -400, and -500 series airplanes). The service bulletin describes procedures for performing a visual inspection of the wires in wire bundle W0024 to connector D04578P on the back of the P15 refuel panel for discrepancies, which would include chafed or burned wires, signs of arcing to the back of the P15 refuel panel and adjacent wing structure, and loose or untied wires and excessive wire loops. The service bulletin also describes procedures for corrective and related investigative actions if any discrepancy is found. Corrective actions include tying and rerouting wires and wire bundle away from sharp edges and components behind the P15 refuel panel; repairing or replacing any chafed or burned wires; and installing Teflon sleeves around the wires as needed for additional protection against chafing. The related investigative action includes measuring the electrical bonding resistance to the P15 panel and performing an operational test of the refuel quantity indicators and valve position lights.

We have also reviewed Boeing Special Attention Service Bulletin 737-28-1200, dated July 10, 2003 (for Model 737-600, -700, -700C, -800, and -900 series airplanes). For Group 1 and Group 2 airplanes, the service bulletin describes procedures for a detailed inspection for discrepancies of the clamp and T-bolt assembly on the wing thermal anti-ice (TAI) duct near the P15 refuel panel. For Group 2 airplanes only, the service bulletin also describes a detailed inspection of the wires in wire bundle W0024 to connector D04578P on the back of the P15 refuel panel for discrepancies such as inadequate clearance between wires and sharp edges, chafed or burned wires, or signs of arcing to the back of the P15 refuel panel and adjacent wing structure. This service bulletin also describes procedures for corrective and related investigative actions, which include repositioning of the clamp and T-bolt assembly on the TAI duct and performing a leak check of the TAI duct; and, as applicable, repairing or replacing any chafed or burned wires; measuring the electrical bonding resistance to the P15 refuel panel; and performing a functional test of the refuel quantity indicators, refuel valve switches, and valve position lights.

Accomplishment of the actions specified in the service bulletins is intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. Therefore, we are proposing this AD, which would require, for certain airplanes, a one-time detailed inspection for interference between a clamp assembly and the wires behind the P15 refuel panel, and corrective actions if necessary. For certain other airplanes, this proposed AD would require a one-time detailed inspection for discrepancies of the wires behind the P15 refuel panel; and corrective actions if necessary. The proposed AD would require you to use the service information described previously to perform these actions, except as discussed under “Differences Between the Proposed AD and Referenced Service Bulletins.”

Differences Between the Proposed AD and Referenced Service Bulletins

Boeing Special Attention Service Bulletin 737-28-1200, dated July 10, 2003, specifies a compliance time of 24 months from the release date of the service bulletin; while Special Attention Service Bulletin 737-28-1193, dated April 24, 2003, specifies a compliance time of 18 months from the release date of the service bulletin. We have determined that the unsafe condition is sufficiently hazardous that a compliance time of 18 months after the effective date of this proposed AD is appropriate for all affected airplanes. This difference has been coordinated with Boeing.

Although Boeing Special Attention Service Bulletin 737-28-1193, dated April 24, 2003, specifies a “visual check,” this proposed AD would require a “detailed inspection.” We have included Note 1 in this proposed AD to define that inspection.

Costs of Compliance

This proposed AD would affect about 1,653 airplanes of U.S. registry and 4,254 airplanes worldwide. The proposed inspections would take about 3 work hours per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $322,335, or $195 per airplane.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 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. 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 proposed AD. 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
• Safety

The Proposed Amendment

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