E9-17932. Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800, -900, and -900ER Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This proposed AD would require replacing the engine fuel shutoff valves for the left and right main tanks. This proposed AD results from a report of a failed engine start, which was caused by an internally fractured engine fuel shutoff valve. We are issuing this AD to prevent the failure of the valve in the closed position, open position, or partially open position, which could result in engine fuel flow problems and possible uncontrolled fuel leak or fire.

DATES:

We must receive comments on this proposed AD by September 14, 2009.

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 proposed AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone [phone], extension 1; fax [phone]; e-mail [e-mail]; Internet https://www.myboeingfleet.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221 or 425-227-1152.

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 [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Samuel Spitzer, 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:

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-2009-0657; Directorate Identifier 2009-NM-048-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 a report of a failed engine start which was caused by a fracture within the engine fuel shutoff valve, also known as the spar valve. Examination of the valve showed a fracture between the splined shaft and the disk portion of the valve. This condition results in an inability to control the valve and could cause the spar valve to position itself in the closed position, open position, or partially open position. If the disc fails in the closed position, engine start problems could result, as only fuel downstream of the valve is available to the engine. If the disk fails in the open or partially open position, the condition is latent, as full thrust can still be achieved and the valve actuator functions and reports to the cockpit normally. Additionally, if the valve fails while partially open, the pressure drop across the valve could affect takeoff suction feed performance if the fuel pumps fail. A failed open or partially open valve cannot shut off fuel flow if there are fuel leakage conditions on the engine side of the valve. This condition could result in engine fuel flow problems and possible uncontrolled fuel leak or fire.

Relevant Service Information

We have reviewed Boeing Service Bulletin 737-28-1272, dated October 31, 2008. The service bulletin describes procedures for replacing the engine fuel spar valves for the left and right main tanks with valves that have a stronger and more wear-resistant splined shaft on the disc portion of the valve.

The service bulletin refers to ITT Aerospace Controls Service Bulletin 125334D-28-02, dated August 27, 2008, as an additional source of service information for modifying the valve body assembly.

FAA's Determination and Requirements of This Proposed AD

We are proposing this AD because we evaluated all relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. This proposed AD would require accomplishing the actions specified in the service information described previously.

Costs of Compliance

We estimate that this proposed AD would affect 883 airplanes of U.S. registry. We also estimate that it would take 26 work-hours per product to comply with this proposed AD. The average labor rate is $80 per work-hour. Required parts would cost up to $8,496 per product. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be up to $9,338,608, or $10,576 per product.

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 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 this 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.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• 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 FAA amends § 39.13 by adding the following new AD:

Boeing: Docket No. FAA-2009-0657; Directorate Identifier 2009-NM-048-AD.

Comments Due Date

(a) We must receive comments by September 14, 2009.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes, certificated in any category; as identified in Boeing Service Bulletin 737-28-1272, dated October 31, 2008.

Subject

(d) Air Transport Association (ATA) of America Code 28: Fuel.

Unsafe Condition

(e) This AD requires replacing engine fuel shutoff valves for the left and right main tanks. This AD results from a report of a failed engine start, which was caused by an internally fractured engine fuel shutoff valve. We are issuing this AD to prevent the failure of the valve in the closed position, open position, or partially open position, which could result in engine fuel flow problems and possible uncontrolled fuel leak or fire.

Compliance

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Replacement of the Engine Fuel Spar Valve Body of the Left and Right Wing Main Tanks

(g) Within 60 months after the effective date of this AD: Replace the engine fuel spar valve bodies of the left and right wing main tanks in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-28-1272, dated October 31, 2008.

Note 1:

Boeing Service Bulletin 737-28-1272, dated October 31, 2008, refers to ITT Aerospace Controls Service Bulletin 125334D-28-02, dated August 27, 2008, as an additional source of service information for modifying the valve body assembly.

Parts Installation

(h) As of the effective date of this AD, no person may install any engine fuel shutoff valve with ITT Aerospace Controls part number 125334D-1 (Boeing part number S343T003-40) on any airplane at the spar valve location. A valve that has been modified in accordance with Boeing Service Bulletin 737-28-1272, dated October 31, 2008, to the new ITT 125334D-2 part number (Boeing part number S343T003-67) may be installed at the spar valve location.

(i) As of the effective date of this AD, no valve with ITT Aerospace Controls part number 125334D-1 (Boeing part number S343T003-40) that has been removed from the spar location may be reinstalled on any airplane in any location unless it has been modified in accordance with Boeing Service Bulletin 737-28-1272, dated October 31, 2008, to the new ITT 125334D-2 part number (Boeing part number S343T003-67).

Alternative Methods of Compliance (AMOCs)

(j)(1) The Manager, Seattle Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Samuel Spitzer, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]. Or, e-mail information to [e-mail].

(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 principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

Issued in Renton, Washington, on July 13, 2009.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.