2011-9894. Airworthiness Directives; The Boeing Company Model 737-700 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 Model 737-700 series airplanes. This proposed AD would require, for certain airplanes, replacing the seat track pivot link assemblies, seat track sections, and floor panels. For certain airplanes, this proposed AD would also require moving certain rows of passenger seats. For certain other airplanes, this proposed AD would require inspecting certain areas of the seat tracks for damage and corrective actions if necessary, and moving certain rows of passenger seats. This proposed AD results from reports that the aft seat leg fittings span the station (STA) 521.45 stay-out zone. We are proposing this AD to prevent failure of the seat attachment structure and possible injury to passengers during an emergency landing.

DATES:

We must receive comments on this proposed AD by June 9, 2011.

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.

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:

Patrick Gillespie, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, 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-2011-0384; Directorate Identifier 2010-NM-058-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 that the aft seat leg fittings span the station (STA) 521.45 stay-out zone. The STA 521.45 stay-out zone defines the flex area of the airplane while in flight and defines fatigue loading of the airplane structure. On some airplanes, the passenger seat leg shear plunger is installed across the seat track pivot joint at approximately STA 521. The existing passenger seat track and pivot link design was not intended to carry seat leg plunger point loads at this location. This condition, if not corrected, could result in failure of the seat attachment structure and possible injury to passengers during an emergency landing.

Relevant Service Information

We have reviewed Boeing Special Attention Service Bulletins 737-25-1598, dated December 8, 2009; and 737-25-1599, dated January 20, 2010. Those special attention service bulletins describe procedures for doing a general visual inspection of the seat tracks in the area of STA 521.45 for damage, and corrective actions if necessary, and moving certain rows of seats. The corrective actions include modifying the seat tracks.

We have also reviewed Boeing Special Attention Service Bulletin 737-53-1286, Revision 1, dated December 14, 2009, which describes procedures for:

• Replacing floor panels with new floor panels between STA 500C and STA 540;
• Replacing seat track pivot link assemblies with new assemblies; and
• Replacing seat track sections between STA 500C + 9.25 and STA 520 with new seat track sections.

We have reviewed Boeing Special Attention Service Bulletin 737-25-1596, dated November 20, 2008, which describes procedures for, among other things, moving certain airplane seats to the correct location on the seat tracks.

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, except as discussed under “Difference Between the Proposed AD and a Service Bulletin.”

Difference Between the Proposed AD and a Service Bulletin

Where Boeing Special Attention Service Bulletin 737-25-1596, dated November 20, 2008, specifies the accomplishment of Recaro Service Bulletin 4400-25DC052, this proposed AD would not require that action.

Costs of Compliance

We estimate that this proposed AD would affect 50 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Table—Estimated Costs

Boeing Service Bulletin	Work hours	Average labor rate per hour	Parts	Cost per product	Number of U.S.-registered airplanes	Fleet cost
737-53-1286	96	$85	Up to $28,258	Up to $36,418	50	Up to $1,820,900.
737-25-1596	4	85	None	340	12	4,080.
737-25-1598	3	85	None	255	1	255.
737-25-1599	3	85	None	255	14	3,570.

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:

The Boeing Company: Docket No. FAA-2011-0384; Directorate Identifier 2010-NM-058-AD.

Comments Due Date

(a) We must receive comments by June 9, 2011.

Affected ADs

(b) None.

Applicability

(c) This AD applies to The Boeing Company Model 737-700 series airplanes, certificated in any category; as identified in the service bulletins specified in paragraphs (c)(1), (c)(2), and (c)(3) of this AD.

(1) Boeing Special Attention Service Bulletin 737-53-1286, Revision 1, dated December 14, 2009.

(2) Boeing Special Attention Service Bulletin 737-25-1598, dated December 8, 2009.

(3) Boeing Special Attention Service Bulletin 737-25-1599, dated January 20, 2010.

Subject

(d) Air Transport Association (ATA) of America Code 25: Equipment/Furnishings.

Unsafe Condition

(e) This AD results from reports that the aft seat leg fittings span the station (STA) 521.45 stay-out zone. The Federal Aviation Administration is issuing this AD to prevent failure of the seat attachment structure and possible injury to passengers during an emergency landing.

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.

Modifying Seat Track Structure

(g) For airplanes identified in Boeing Special Attention Service Bulletin 737-53-1286, Revision 1, dated December 14, 2009: Within 72 months after the effective date of this AD, replace, with new components, certain floor panels, seat track pivot link assemblies, and seat track sections with new components, and modify certain seat tracks, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-53-1286, Revision 1, dated December 14, 2009.

Moving Seat Rows After Modifying Seat Track Structure

(h) For airplanes identified in Boeing Special Attention Service Bulletin 737-25-1596, dated November 20, 2008: Move certain seat rows in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-25-1596, dated November 20, 2008, at the applicable time required in paragraph (h)(1) or (h)(2) of this AD.

(1) For airplanes identified in Boeing Special Attention Service Bulletin 737-53-1286, Revision 1, dated December 14, 2009: After accomplishing the requirements of paragraph (g) of this AD but within 72 months after the effective date of this AD.

(2) For airplanes not identified in Boeing Special Attention Service Bulletin 737-53-1286, Revision 1, dated December 14, 2009: Within 72 months after the effective date of this AD.

Moving Seat Rows and General Visual Inspection of Seat Tracks

(i) For airplanes identified in Boeing Special Attention Service Bulletin 737-25-1598, dated December 8, 2009: Within 72 months after the effective date of this AD, do a general visual inspection of certain areas of the seat tracks for damage, all applicable corrective actions, and move certain seat rows, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-25-1598, dated December 8, 2009. Do all applicable corrective actions before further flight.

(j) For airplanes identified in Boeing Special Attention Service Bulletin 737-25-1599, dated January 20, 2010: Within 72 months after the effective date of this AD, do a general visual inspection of certain areas of the seat tracks for damage, do all applicable corrective actions, and move certain seat rows, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-25-1599, dated January 20, 2010. Do all applicable corrective actions before further flight.

Alternative Methods of Compliance (AMOCs)

(k)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in the Related Information section of this AD. Information may be e-mailed to: [e-mail].

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.

Related Information

(l) For more information about this AD, contact Patrick Gillespie, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]; e-mail [e-mail].

(m) For service information identified in this 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.

Issued in Renton, Washington, on April 15, 2011.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.