E8-971. Airworthiness Directives; McDonnell Douglas Model 717-200 Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

We are adopting a new airworthiness directive (AD) for certain McDonnell Douglas Model 717-200 airplanes. This AD requires modification of the conduit for the forward boost pump of the center fuel tank. This AD results from the finding that a potential chafing condition exists in the volute assembly of the forward boost pump for the center fuel tank. We are issuing this AD to prevent chafing of the fuel boost pump wiring that could lead to arcing to the inside of the 45-degree angle fitting, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

DATES:

This AD is effective February 28, 2008.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of February 28, 2008.

ADDRESSES:

For service information identified in this AD, contact Boeing Commercial Airplanes, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024).

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 AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (telephone [phone]) is the Document Management Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT:

Samuel S. Lee, Aerospace Engineer, Propulsion Branch, ANM-140L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain McDonnell Douglas Model 717-200 airplanes. That NPRM was published in the Federal Register on October 11, 2007 (72 FR 57892). That NPRM proposed to require modification of the conduit for the forward boost pump of the center fuel tank.

Comments

We gave the public the opportunity to participate in developing this AD. We have considered the two comments received from the one commenter.

Support for the NPRM

AirTran Airways supports the NPRM.

Request To Allow Use of Original Issue of Service Bulletin

AirTran Airways requests that we revise this AD to specify that actions accomplished before the effective date of this AD in accordance with Boeing Service Bulletin 717-28-0007, dated August 22, 2002, are considered acceptable for compliance with the corresponding actions specified in paragraph (f) of this AD provided that a leak check of the conduit is accomplished in accordance with Boeing 717 Airplane Maintenance Manual (AMM) Task 28-22-28-700-801, “Leak Test of the Fuel Pump Electrical Conduit.” AirTran Airways has accomplished the actions specified in the original issue of the service bulletin on all applicable airplanes in its fleet. AirTran Airways states that Revision 1, dated September 23, 2003, of the service bulletin was published to provide a torque value for the conduits due to an instance of fuel leaking from the conduit at the front spar following accomplishment of the task. AirTran Airways notes that it accomplished a leak check of the conduit during accomplishment of the original issue of the service bulletin, and that the leak check was later added to the AMM in January 2004, as AMM Task 28-22-28-700-801. The leak check of the conduit ensured that the conduit was not leaking, in the absence of a specified torque value in the original issue of the service bulletin. AirTran Airways believes that, if operators have accomplished the modification in accordance with the original issue of the service bulletin, accomplishing a leak check of the conduits using AMM Task 28-22-28-700-801 should be acceptable to ensure that the conduits are not leaking in lieu of accessing the conduit connections again for a torque check.

We agree that work done in accordance with Boeing Service Bulletin 717-28-0007, dated August 22, 2002, is acceptable for compliance with the requirements of this AD provided that a leak check of the conduit is accomplished in accordance with Boeing 717 AMM Task 28-22-28-700-801. We have added a new paragraph (g) to this AD to allow credit for previous accomplishment.

Conclusion

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the change described previously. We also determined that this change will not increase the economic burden on any operator or increase the scope of the AD.

Costs of Compliance

There are about 77 airplanes of the affected design in the worldwide fleet. This AD affects about 61 airplanes of U.S. registry. The required actions take about 10 work hours per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the AD for U.S. operators is $48,800, or $800 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

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 this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Is not a “significant rule” under 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

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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:

2008-02-12 McDonnell Douglas: Amendment 39-15342. Docket No. FAA-2007-29329; Directorate Identifier 2007-NM-205-AD.

Effective Date

(a) This airworthiness directive (AD) is effective February 28, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to McDonnell Douglas Model 717-200 airplanes, certificated in any category; as identified in Boeing Service Bulletin 717-28-0007, Revision 1, dated September 23, 2003.

Unsafe Condition

(d) This AD results from a finding that a potential chafing condition exists in the volute assembly of the forward boost pump for the center fuel tank. We are issuing this AD to prevent chafing of the forward boost pump wiring that could lead to arcing to the inside of the 45-degree angle fitting, which, 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.

Modification

(f) Within 78 months after the effective date of this AD, modify the conduit for the forward fuel boost pump of the center fuel tank, by accomplishing all of the actions specified in Boeing Service Bulletin 717-28-0007, Revision 1, dated September 23, 2003.

Credit for Actions Done According to Previous Issue of Service Bulletin

(g) Actions done before the effective date of this AD in accordance with Boeing Service Bulletin 717-28-0007, dated August 22, 2002, are acceptable for compliance with the requirements of paragraph (f) of this AD provided that a leak check of the conduit is accomplished in accordance with Boeing 717 Airplane Maintenance Manual (AMM) Task 28-22-28-700-801, “Leak Test of the Fuel Pump Electrical Conduit.”

Alternative Methods of Compliance (AMOCs)

(h)(1) The Manager, Los Angeles 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.

Material Incorporated by Reference

(i) You must use Boeing Service Bulletin 717-28-0007, Revision 1, dated September 23, 2003, to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024).

(3) You may review copies of the service information incorporated by reference 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/​code_​of_​federal_​regulations/​ibr_​locations.html.

Issued in Renton, Washington, on January 14, 2008.

Stephen P. Boyd,

Assistant Manager, Transport Airplane Directorate, Aircraft Certification Service.