Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

SUMMARY:

We are revising an earlier proposed airworthiness directive (AD) for certain The Boeing Company Model 737-600, -700, -700C, -800, -900 and -900ER series airplanes. That NPRM proposed to require modifying the fluid drain path in the wing leading edge area, forward of the wing front spar, and doing all applicable related investigative and corrective actions. That NPRM was prompted by a report of leaking fuel from the wing leading edge area at the inboard end of the number 5 leading edge slat. This action revises that NPRM by including installing new seal disks on the latches in the fuel shutoff valve access door as part of the modification and by specifying that certain inspections are detailed inspections. This action also revises the applicability to include additional airplanes. We are proposing this AD to prevent flammable fluids from accumulating in the wing leading edge, and draining inboard and onto the engine exhaust nozzle, which could result in a fire. Since these actions impose an additional burden over that proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on these proposed changes.

DATES:

We must receive comments on this supplemental NPRM by April 30, 2012.

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, 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 proposed AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; email me.boecom@boeing.com; 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.

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 (74 FR 15683, April 7, 2009), the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (phone: 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Chris Parker, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: 425-917-6496; fax: 425-917-6590; email: chris.r.parker@faa.gov.

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-2009-0288; Directorate Identifier 2008-NM-214-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 issued an NPRM to amend 14 CFR part 39 to include an AD that would apply to Model 737-600, -700, -700C, -800, -900 and -900ER series airplanes. That NPRM published in the Federal Register on April 7, 2009 (74 FR 15683). That NPRM proposed to require modifying the fluid drain path in the wing leading edge area, forward of the wing front spar, and doing all applicable related investigative and corrective actions.

Actions Since Previous NPRM Was Issued

Since we issued the previous NPRM (74 FR 15683, April 7, 2009), Boeing issued Special Attention Service Bulletin 737-57-1293, Revision 2, dated September 28, 2011, to add actions to the modification of the fluid drain path in the wing leading edge area, forward of the wing front spar. The additional actions are installing new seal disks on the latches in the fuel shutoff valve access door. Boeing Special Attention Service Bulletin 737-57-1293, Revision 2, dated September 28, 2011, also adds airplanes with line numbers 2438 through 3833 inclusive to the effectivity. The service information also changed the general visual inspection of the countersink diameter for the bonding jumper fastener hole to a detailed inspection.

Comments

We gave the public the opportunity to comment on the previous NPRM (74 FR 15683, April 7, 2009). The following presents the comments received on the NPRM and the FAA's response to each comment.

Request To Extend Compliance Time

Air Transport Association, on behalf of its members American Airlines (AAL) and AirTran Airways, requested that we extend the compliance time of the proposed AD (74 FR 15683, April 7, 2009). AAL requested that the proposed compliance time of 24 months be changed to 72 months. AAL stated that the proposed compliance time of 24 months does not integrate into the current operator maintenance program without significant aircraft maintenance planning adjustments and additional costs. AAL stated that a 72-month compliance time would fit within the maintenance review board heavy C-check schedule.

We do not agree with the commenter's request to extend the compliance time. Extending the compliance time to 72 months would result in an unacceptable level of risk for the Model 737-600, -700, -700C, -800, -900, and -900ER fleet. We have determined that the compliance time of 24 months represents the maximum interval of time allowable for the affected airplanes to continue to safely operate before the modification is done. Under the provisions of paragraph (h) of this supplemental NPRM, however, we may consider requests for adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety. We have not changed the supplemental NPRM in this regard.

Request To Refer to Revised Service Bulletin

Boeing and the Air Transport Association, on behalf of its member AAL, requested that we refer to Boeing Special Attention Service Bulletin 737-57-1293, Revision 1, dated January 11, 2010, in order to incorporate new changes and to prevent issuance of alternative methods of compliance (AMOC).

We disagree with the request to refer to Boeing Special Attention Service Bulletin 737-57-1293, Revision 1, dated January 11, 2010. Since the date of the commenters' requests, Boeing has issued Special Attention Service Bulletin 737-57-1293, Revision 2, dated September 28, 2011 (described previously), which adds more new changes. We have changed paragraphs (c) and (g) of this supplemental NPRM to refer to Boeing Special Attention Service Bulletin 737-57-1293, Revision 2, dated September 28, 2011.

FAA's Determination

We are proposing this supplemental NPRM because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of these same type designs. Certain changes described above expand the scope of the original NPRM (74 FR 15683, April 7, 2009). As a result, we have determined that it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this supplemental NPRM.

Proposed Requirements of the Supplemental NPRM

This supplemental NPRM would require accomplishing the actions specified in the service information described previously.

Costs of Compliance

We estimate that this proposed AD affects 1,072 airplanes of U.S. registry.

We estimate the following costs to comply with this proposed AD:

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),

(3) Will not affect intrastate aviation in Alaska, and

(4) 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.

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.