E7-16909. Airworthiness Directives; Boeing Model 737-300, -400, and -500 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Final rule; request for comments.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-300, -400, and -500 series airplanes. This AD requires an inspection of the seat locks and seat tracks of the flightcrew seats to ensure that the seats lock in position and to verify that lock nuts and bolts of adequate length are installed on the rear tracklock bracket, and corrective actions if necessary. This AD results from a report indicating that the captain's seat slid aft and jammed during taxi. We are issuing this AD to prevent uncommanded movement of the flightcrew seats during acceleration and take-off of the airplane, which could result in reduced controllability of the airplane.

DATES:

This AD becomes effective September 12, 2007.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of September 12, 2007.

We must receive comments on this AD by October 29, 2007.

ADDRESSES:

Use one of the following addresses to submit comments on this AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• 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.
• Fax: [phone].
• Hand Delivery: Room W12-140 on the ground floor of the West Building, 1200 New Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for service information identified in this AD.

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:

Discussion

We have received a report indicating that the captain's seat slid aft and jammed during taxi. A subsequent investigation found that two of the three screws attaching the rear tracklock bracket broke. The broken screws allowed excessive lateral movement and disengagement of the locking pin from the floor-mounted seat track. In addition, we have received some reports of loosened screws that attach the tracklock bracket to the rear cross member of the seat base. An incorrectly aligned seat track locking pin can cause the locking pin to not fully engage the seat track. These conditions, if not corrected, could result in uncommanded movement of the flightcrew seats during acceleration and take-off of the airplane, which could result in reduced controllability of the airplane.

Other Related Rulemaking

We previously issued AD 2004-04-03, amendment 39-13483 (69 FR 7565, February 18, 2004), applicable to certain Boeing Model 737-300, -400, and -500 series airplanes. (A correction of AD 2004-04-03 was published in the Federal Register on April 13, 2004 (69 FR 19313).) That AD requires a one-time general visual inspection of the seat locks and seat tracks of the flightcrew seats to ensure that the seats lock in position and to verify that lock nuts and bolts of adequate length are installed on the rear track lock bracket, and corrective action, if necessary.

Since issuance of AD 2004-03-03, we have determined that the same unsafe condition addressed in that AD may exist on certain additional Boeing Model 737-300, -400, and -500 series airplanes. Boeing has advised us that airplanes having variable numbers PS971 through PS978, PT187, and PT188 were omitted inadvertently from the effectivity of Boeing Alert Service Bulletin 737-25A1363, Revision 1, dated March 28, 2002 (referred to in the applicability of AD 2004-04-03 as the appropriate source of service information for identifying the affected airplanes). Therefore, these additional airplanes are also subject to the same unsafe condition addressed in AD 2004-03-03.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 737-25A1363, Revision 2, dated May 2, 2006. Revision 2 was issued to add airplanes having variable numbers PS971 through PS978, PT187, and PT188, and to make editorial changes. The procedures for inspecting the seat locks and seat tracks of the flightcrew seats, and corrective actions if necessary, are essentially identical to those in Revision 1 of the service bulletin. No more work is necessary on airplanes changed as shown in Boeing Alert Service Bulletin 737-25A1363, dated November 5, 1998, or Revision 1, dated March 28, 2002. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

Boeing Alert Service Bulletin 737-25A1363 refers to IPECO Service Bulletin A001-25-47, Issue 2, dated July 31, 2002, as an additional source of service information for accomplishment of the inspection and rework.

FAA's Determination and Requirements of This AD

The unsafe condition described previously is likely to exist or develop on other airplanes of the same type design that may be registered in the U.S. at some time in the future. Therefore, we are issuing this AD to prevent uncommanded movement of the flightcrew seats during acceleration and take-off of the airplane, which could result in reduced controllability of the airplane. This AD requires accomplishing the actions specified in the service information described previously.

Costs of Compliance

None of the airplanes affected by this action are on the U.S. Register. All airplanes affected by this AD are currently operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, we consider this AD necessary to ensure that the unsafe condition is addressed if any affected airplane is imported and placed on the U.S. Register in the future.

If an affected airplane is imported and placed on the U.S. Register in the future, the required actions would take between 1 and 3 work hours per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the AD would be between $80 and $240 per airplane.

FAA's Determination of the Effective Date

No airplane affected by this AD is currently on the U.S. Register. Therefore, providing notice and opportunity for public comment is unnecessary before this AD is issued, and this AD may be made effective in less than 30 days after it is published in the Federal Register.

Comments Invited

This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any relevant written data, views, or arguments regarding this AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2007-29071; Directorate Identifier 2007-NM-097-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD that might suggest a need to modify it.

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Operations office (telephone [phone]) is located on the ground level of the West Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

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 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 the 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 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
• 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 Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

2007-18-03 Boeing: Amendment 39-15183. Docket No. FAA-2007-29071; Directorate Identifier 2007-NM-097-AD.

Effective Date

(a) This AD becomes effective September 12, 2007.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 737-300, -400, and -500 series airplanes, variable numbers PS971 through PS978, PT187, and PT188, certificated in any category.

Unsafe Condition

(d) This AD results from a report indicating that the captain's seat slid aft and jammed during taxi. We are issuing this AD to prevent uncommanded movement of the flightcrew seats during acceleration and take-off of the airplane, which could result in reduced controllability 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.

Inspection and Corrective Action

(f) Within 90 days after the effective date of this AD, do a one-time general visual inspection of the seat locks and seat tracks of the flightcrew seats to ensure that the seats lock in position and to verify that lock nuts and bolts of adequate length are installed on the rear tracklock bracket, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-25A1363, Revision 2, dated May 2, 2006.

(1) If the seat lock pin fully engages in all lock positions of the seat track, and the rear track lock bracket is correctly installed: No further action is required by this AD.

(2) If the seat lock pin does not fully engage in all positions of the seat track, before further flight, make sure the flightcrew seat operates correctly, in accordance with the service bulletin.

(3) If the lock nuts and bolts of adequate length are not installed on the rear tracklock bracket, before further flight, rework the flightcrew seat in accordance with the service bulletin.

Note 1:

For the purposes of this AD, a general visual inspection is: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

Note 2:

Boeing Alert Service Bulletin 737-25A1363, Revision 2, dated May 2, 2006, refers to IPECO Service Bulletin A001-25-47, Issue 2, dated July 31, 2002, as an additional source of service information for accomplishment of the inspection and rework required by paragraphs (f) and (f)(3) of this AD, respectively.

(g) Actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin 737-25A1363, dated November 5, 1998; or Revision 1, dated March 28, 2002, is acceptable for compliance with the corresponding action specified in this AD.

Alternative Methods of Compliance (AMOCs)

(h)(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.

Material Incorporated by Reference

(i) You must use Boeing Alert Service Bulletin 737-25A1363, Revision 2, dated May 2, 2006, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy of this service information. You may review copies at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, S.W., 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/​cfr/​ibr-locations.html.

Issued in Renton, Washington, on August 17, 2007.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.