E7-11926. Airworthiness Directives; Boeing Model 767-200, -300, and -300F Series Airplanes

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 767-200, -300, and -300F series airplanes. This proposed AD would require a one-time inspection of each fuel quantity indication system (FQIS) wire harness connector for corrosion of the shield-to-backshell connection, corrosion on the ground jumper, and damage to the ground jumper; a loop resistance test of each FQIS wire harness; and related investigative and corrective actions if necessary. This proposed AD results from reports of corrosion of the out-tank wire harness of the spar connector backshell for the FQIS. We are proposing this AD to detect and correct corrosion of the out-tank wire harness, which could prevent correct grounding of the lightning shield and result in total loss of the electrical grounding between the lightning shield and the airplane structure. This condition, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.

DATES:

We must receive comments on this proposed AD by August 6, 2007.

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: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Fax: [phone].
• Hand Delivery: Room W12-140 on the ground floor of the West Building, 1200 New Jersey Avenue, SE., 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 the service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Philip Sheridan, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2007-28376; Directorate Identifier 2007-NM-108-AD” at the beginning 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 received 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.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov,, or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Operations office (telephone [phone]) is located on the ground floor of the West Building at the street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

Discussion

There have been several reports of corrosion of the out-tank wire harness of the spar connector backshell for the fuel quantity indication system (FQIS). Investigations by the airplane manufacturer and the wire harness supplier found that the corrosion was caused by moisture at the connection between the lightning shield, a tin-plated copper braid, and the aluminum backshell. The moisture wicked up the copper braid and was trapped between the ferrule and the backshell. Corrosion of the out-tank wire harness, if not detected and corrected, could prevent correct grounding of the lightning shield and result in total loss of the electrical grounding between the lightning shield and the airplane structure. This condition, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.

Relevant Service Information

We have reviewed Boeing Special Attention Service Bulletin 767-28-0087, dated February 5, 2007. The service bulletin describes procedures for a detailed inspection of each FQIS wire harness connector for corrosion of the shield-to-backshell connection, corrosion on the ground jumper, and damage to the ground jumper. The service bulletin also describes procedures for corrective action if necessary. The corrective action is either upgrading the wire harness by installing a backshell assembly upgrade kit, or replacing the wire harness with a new wire harness that has an improved backshell.

The service bulletin also describes procedures for a loop resistance test of each FQIS wire harness, and the following related investigative and corrective actions if necessary.

• If the resistance is lower than certain limits specified in the service bulletin, the procedures include a detailed inspection for damage of the wire harness between the spar connector and the wheel well ground terminals; and repair or replacement if necessary.
• If the resistance is higher than certain limits specified in the service bulletin, the procedures include doing a joint resistance test of the rear spar ground jumper, and troubleshooting and repairing the ground jumper connection if necessary.

Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

The special attention service bulletin refers to Cinch Service Bulletin CN1156-28-02, Revision C, dated July 31, 2006, as an additional source of service information for installing a backshell assembly upgrade kit and replacing the wire harness.

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. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously.

Costs of Compliance

There are about 482 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

Action	Work hours	Average labor rate per hour	Cost per airplane	Number of U.S.-registered airplanes	Fleet cost
Detailed inspection	1	$80	$80	202	$16,160.
Loop resistance test	2 to 3	$80	$160 to $240	202	$32,320 to $48,480.

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 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 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
• 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.

§ 39.13

[Amended]

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

Boeing: Docket No. FAA-2007-28376; Directorate Identifier 2007-NM-108-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by August 6, 2007.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 767-200, -300, and -300F series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 767-28-0087, dated February 5, 2007.

Unsafe Condition

(d) This AD results from reports of corrosion of the out-tank wire harness of the spar connector backshell for the fuel quantity indication system (FQIS). We are issuing this AD to detect and correct corrosion of the out-tank wire harness, which could prevent correct grounding of the lightning shield and result in total loss of the electrical grounding between the lightning shield and the airplane structure. This condition, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.

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, Test, and Related Investigative and Corrective Actions

(f) Within 48 months after the effective date of this AD, do the actions in paragraphs (f)(1) and (f)(2) of this AD, and do all applicable related investigative and corrective actions, by accomplishing all the actions specified in the Accomplishment Instructions of Boeing Special Attention Service Bulletin 767-28-0087, dated February 5, 2007. Do all applicable related investigative and corrective actions before further flight.

(1) A detailed inspection of each FQIS wire harness connector for corrosion of the shield-to-backshell connection, corrosion on the ground jumper, and damage to the ground jumper.

(2) A loop resistance test of each FQIS wire harness.

Note 1:

Boeing Special Attention Service Bulletin 767-28-0087, dated February 5, 2007, refers to Cinch Service Bulletin CN1156-28-02, Revision C, dated July 31, 2006, as an additional source of service information for installing a backshell assembly upgrade kit, and replacing the wire harness.

Alternative Methods of Compliance (AMOCs)

(g)(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) 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.

Issued in Renton, Washington, on June 13, 2007.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.