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

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 737 series airplanes, that currently 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. This amendment revises the applicability of the existing AD by adding airplanes. The actions specified by this AD are intended 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 action is intended to address the identified unsafe condition.

DATES:

Effective March 24, 2004.

The incorporation by reference of a certain publication listed in the regulations is approved by the Director of the Federal Register as of March 24, 2004.

The incorporation by reference of a certain other publication, as listed in the regulations, was approved previously by the Director of the Federal Register as of June 12, 2000 (65 FR 34063, May 26, 2000).

ADDRESSES:

The service information referenced in this AD may be obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Shannon Lennon, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington; telephone (425) 917-6435; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 2000-10-21, amendment 39-11745 (65 FR 34063, May 26, 2000), which is applicable to certain Boeing Model 737 series airplanes, was published in the Federal Register on December 5, 2003 (68 FR 67975). The action proposed to continue to require 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. The action also proposed to revise the applicability of the existing AD by adding airplanes.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Conclusion

The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact

There are approximately 1,385 airplanes of the affected design in the worldwide fleet. The FAA estimates that 282 airplanes of U.S. registry will be affected by this AD.

For Group 1 airplanes listed in Boeing Alert Service Bulletin 737-25A1363, Revision 1: The actions that are currently required by AD 2000-10-21 take approximately 3 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $195 per airplane.

For Group 2 airplanes listed in Boeing Alert Service Bulletin 737-25A1363, Revision 1: The new actions that are required by this AD will take approximately 3 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the new requirements of this AD on U.S. operators is estimated to be $195 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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.

2. Section 39.13 is amended by removing amendment 39-11745 ( 65 FR 34063, May 26, 2000), and by adding a new airworthiness directive (AD), amendment 39-13483, to read as follows:

2004-04-03 Boeing: Amendment 39-13483. Docket 2002-NM-174-AD. Supersedes AD 2000-10-21, Amendment 39-11745.

Applicability: Model 737-300, -400, and -500 series airplanes equipped with IPECO flightcrew seats, as listed in Boeing Alert Service Bulletin 737-25A1363, Revision 1, dated March 28, 2002; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

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, accomplish the following:

One-Time Inspection

(a) Perform 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, at the applicable time and per the Work Instructions of the applicable service bulletin specified in Table 1 of this AD. Table 1 follows:

Note 1:

For the purposes of this AD, a general visual inspection is defined as: “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 enhance visual access to all exposed 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.”

Corrective Action

(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, and lock nuts and bolts of adequate length are not installed on the rear track lock bracket: Prior to further flight, install lock nuts and bolts of adequate length on the track lock bracket and verify proper seat movement and seat lock operation, in accordance with the applicable service bulletin.

Note 2:

Boeing Alert Service Bulletin 737-25A1363, Revision 1, dated March 28, 2002, refers to IPECO Service Bulletin A001-25-47, dated January 13, 1992, as an additional source of service information for accomplishment of the actions required by paragraph (a) of this AD.

Actions Accomplished Per Previous Issue of Service Bulletin

(b) For Group 2 airplanes: Inspections and corrective actions accomplished before the effective date of this AD per Boeing Alert Service Bulletin 737-25A1363, dated November 5, 1998, are considered acceptable for compliance with the corresponding actions specified in this AD.

Alternative Methods of Compliance

(c)(1) In accordance with 14 CFR 39.19, the Manager, Seattle Aircraft Certification Office (ACO), FAA, is authorized to approve alternative methods of compliance (AMOCs) for this AD.

(2) Alternative methods of compliance, approved previously per AD 2000-10-21, amendment 39-11745, are approved as alternative methods of compliance with the requirements of this AD.

Incorporation by Reference

(d) Unless otherwise specified in this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 737-25A1363, dated November 5, 1998; or Boeing Alert Service Bulletin 737-25A1363, Revision 1, dated March 28, 2002; as applicable.

(1) The incorporation by reference of Boeing Alert Service Bulletin 737-25A1363, Revision 1, dated March 28, 2002, is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) The incorporation by reference of Boeing Alert Service Bulletin 737-25A1363, dated November 5, 1998, was approved previously by the Director of the Federal Register as of June 12, 2000 (65 FR 34063, May 26, 2000).

(3) Copies may be obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

(e) This amendment becomes effective on March 24, 2004.