Airworthiness Directives; Boeing Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment revises an existing airworthiness directive (AD), applicable to certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, that currently requires replacing existing screw, nut, and washers that attach the latch cable assembly to the latch block assembly of the door mounted escape slides, with new, improved screw, nut, and washers. The actions specified by that AD are intended to prevent the latch cable assembly from disconnecting from the latch block assembly of the door mounted escape slide, which could result in an escape slide not deploying in an emergency situation. This amendment revises the parts installation paragraph to allow certain nuts to be installed and is intended to address the identified unsafe condition.

DATES:

Effective July 21, 2004.

The incorporation by reference of a certain publication, as listed in the regulations, was approved previously by the Director of the Federal Register as of March 24, 2004 (69 FR 7553, February 18, 2004).

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 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.

FOR FURTHER INFORMATION CONTACT:

Keith Ladderud, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; 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 revising AD 2004-03-34, amendment 39-13478 (69 FR 7553, February 18, 2004), which is applicable to certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, was published in the Federal Register on March 24, 2004 (69 FR 13761). The action proposed to continue to require replacing the existing screw, nut, and washers that attach the latch cable assembly to the latch block assembly of the door mounted escape slides, with new, improved screw, nut, and washers. In addition, the action proposed to revise the parts installation paragraph to allow certain nuts to be installed on the latch block assembly.

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

The changes in this action add no additional economic burden. The current costs for this AD are repeated for the convenience of affected operators, as follows:

There are approximately 2,919 airplanes of the affected design in the worldwide fleet. The FAA estimates that 1,129 airplanes of U.S. registry will be affected by this AD. The FAA estimates that it will take approximately 2 work hours for each airplane specified as Group 1 in the referenced service bulletin, and approximately 1 work hour for each airplane specified as Group 2 in the referenced service bulletin, to accomplish the required actions; the average labor rate is estimated to be $65 per work hour. Parts and materials are standard and are to be supplied by the operator. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $130 per Group 1 airplane, and $65 per Group 2 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. The manufacturer may cover the cost of replacement parts associated with this AD, subject to warranty conditions. Manufacturer warranty remedies may also be available for labor costs associated with this AD. As a result, the costs attributable to the AD may be less than stated above.

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 39-13478 ( 69 FR 7553, February 18, 2004), and by adding a new airworthiness directive (AD), amendment 39-13673, to read as follows:

2004-03-34 R1 Boeing: Docket 2004-NM-29-AD. Revises AD 2004-03-34, Amendment 39-13478.

Applicability: Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, as listed in Boeing Special Attention Service Bulletin 737-25-1434, dated March 22, 2001; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent the latch cable assembly from disconnecting from the latch block assembly of the door mounted escape slide, which could result in an escape slide not deploying in an emergency situation, accomplish the following:

Replacement

(a) Within 36 months after the effective date of this AD, replace existing screw, nut, and washers that attach the latch cable assembly to the latch block assembly of the door mounted escape slides, with new, improved screw, nut, and washers; per the Work Instructions of Boeing Special Attention Service Bulletin 737-25-1434, dated March 22, 2001.

Parts Installation

(b) As of the effective date of this AD, no person may install either of the parts specified in paragraphs (b)(1) and (b)(2) of this AD on the latch block assembly of any airplane.

(1) A nut, part number (P/N) BACN10R10L, that has been removed from any airplane.

(2) A screw, P/N NAS623-3-8.

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 (AMOC) for this AD.

(2) An AMOC that provides an acceptable level of safety may be used for repair of the latch cable assembly and the latch block assembly for the door mounted escape slide, if it is approved by a Boeing Company Designated Engineering Representative (DER) who has been authorized by the Manager, Seattle ACO, to make such findings.

Incorporation by Reference

(d) The actions shall be done in accordance with Boeing Special Attention Service Bulletin 737-25-1434, dated March 22, 2001. The incorporation by reference of that document was approved previously by the Director of the Federal Register as of March 24, 2004 (69 FR 7553, February 18, 2004). 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 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.

Effective Date

(e) This amendment becomes effective on July 21, 2004.