Airworthiness directives: Boeing,

[Federal Register: November 9, 2007 (Volume 72, Number 217)]

[Proposed Rules]

[Page 63512-63513]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr09no07-22]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0175; Directorate Identifier 2007-NM-184-AD]

RIN 2120-AA64

Airworthiness Directives; Boeing Model 757 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 757 airplanes. This proposed AD would require changing the wiring of the fuel boost pump and doing other specified actions. This proposed AD results from reports of short circuits in an electrical connector at the wing-to-body electrical disconnect panel. We are proposing this AD to prevent a short circuit of the electrical connector for the fuel boost pump, which could cause the instruments for fuel, flap, slat, and aileron systems to malfunction and create a potential ignition source inside the fuel tanks. A potential ignition source inside the fuel tank in combination with flammable fuel vapors could result in a fuel tank explosion and consequent loss of the airplane.

DATES: We must receive comments on this proposed AD by December 24, 2007.

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: 202-493-2251.

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 proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

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 (425) 917-6441; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include ``Docket No. FAA-2007-0175; Directorate Identifier 2007-NM-184-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed 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 proposed AD.

Discussion

We have received reports indicating that short circuits occurred in an electrical connector at the wing-to-body electrical disconnect panel, on three Boeing Model 757 airplanes. The airplanes had accumulated between 27,040 and 50,735 total flight hours. On two of the airplanes, the short circuit damaged the fuel quantity indicating system (FQIS) wiring. Wires for some of the fuel boost pumps for the main tank use the same electrical connectors as wires for the FQIS and densitometer circuits. Contamination in these electrical circuits could cause a short circuit from the fuel boost pump wiring to the FQIS and densitometer wiring. A short circuit can put a high-energy electrical transient into the fuel tanks that can act as a potential ignition source. The high-energy electrical transients could also cause the instruments for the fuel, flap, slat, and aileron systems to malfunction. A potential ignition source inside the fuel tank in combination with flammable fuel vapors, if not corrected, could result in a fuel tank explosion and consequent loss of the airplane.

Relevant Service Information

We have reviewed Boeing Special Attention Service Bulletin 757-28- 0095, dated June 18, 2007, for Model 757-200, -200PF, and -200CB series airplanes; and Boeing Special Attention Service Bulletin 757-28-0096, dated June 18, 2007, for Model 757-300 series airplanes. The service bulletins describe procedures for changing the wiring of the fuel boost pump and doing other specified actions. The other specified actions include doing functional tests of the affected airplane systems. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

[[Page 63513]]

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 1,697 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 673 airplanes of U.S. registry. The proposed actions would take up to 12 work hours per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $646,080, or $960 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 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.

   Sec. 39.13 [Amended]

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

   Airbus: Docket No. FAA-2007-0175; Directorate Identifier 2007-NM- 184-AD.

   Comments Due Date

   (a) The FAA must receive comments on this AD action by December 24, 2007.

   Affected ADs

   (b) None.

   Applicability

   (c) This AD applies to the airplanes identified in paragraphs (c)(1) and (c)(2) of this AD, certificated in any category.

   (1) Boeing Model 757-200, -200PF, and -200CB series airplanes, as identified in Boeing Special Attention Service Bulletin 757-28- 0095, dated June 18, 2007.

   (2) Boeing Model 757-300 series airplanes, as identified in Boeing Special Attention Service Bulletin 757-28-0096, dated June 18, 2007.

   Unsafe Condition

   (d) This AD results from reports of short circuits in an electrical connector at the wing-to-body electrical disconnect panel. We are issuing this AD to prevent a short circuit of the electrical connector for the fuel boost pump, which could cause the instruments for the fuel, flap, slat, and aileron systems to malfunction and create a potential ignition source inside the fuel tank. A potential ignition source inside the fuel tank in combination with flammable fuel vapors could result in a fuel tank explosion 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.

   Fuel Boost Pump Wiring Change

   (f) Within 60 months after the effective date of this AD, change the wiring of the fuel boost pump and do all other specified actions as applicable, by accomplishing all of the applicable actions specified in the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-28-0095, dated June 18, 2007 (for Model 757-200, -200PF, and -200CB series airplanes); or Boeing Special Attention Service Bulletin 757-28-0096, dated June 18, 2007 (for Model 757-300 series airplanes); as applicable. The other specified actions must be done before further flight after changing the fuel boost pump wiring.

   Alternative Methods of Compliance (AMOCs)

   (g)(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.

   Issued in Renton, Washington, on November 2, 2007. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E7-22009 Filed 11-8-07; 8:45 am]

   BILLING CODE 4910-13-P