Federal Aviation Administration (FAA), Department of Transportation (DOT).
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737 airplanes. This AD requires modifying the elevator input torque tube assembly. This AD results from a report of a restriction in the pilot's elevator input control system. A design review performed on the elevator input torque tube assembly in the course of the investigation discovered possible failure modes that could lead to a jam of the elevator control system. We are issuing this AD to prevent loss of elevator control and consequent reduced controllability of the airplane.
This AD becomes effective January 20, 2006.
The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of January 20, 2006.
You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, Washington, DC.
Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for service information identified in this AD.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Douglas Tsuji, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6487; fax (425) 917-6590.End Further Info End Preamble Start Supplemental Information
Examining the Docket
You may examine the airworthiness directive (AD) docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the street address stated in the ADDRESSES section.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to certain Boeing Model 737-100, -200, -200C, -300, -400, -500, -600, -700, -700C, -800 and -900 series airplanes. That NPRM was published in the Federal Register on July 5, 2005 (70 FR 38630). That NPRM proposed to require modifying the elevator input torque tube assembly.
We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.
Support for the Proposed AD
One commenter states that although the proposed AD does not affect any airplane in its fleet, it supports the actions in the AD.
Request To Clarify Summary
The airplane manufacturer requests that we revise the third sentence in the Summary section of the proposed AD from, “This proposed AD is prompted by a report of a restriction in the pilot's elevator control system,” to “This proposed AD is prompted by the results of a design review performed on the input torque tube assembly, which discovered possible failure modes that could lead to a jam of the elevator control system.” The commenter explains that the sentence, as proposed, may be misleading by connecting the pilots' reported condition to the hypothetical jam that is addressed by the proposed AD.
We partially agree with the commenter. We agree that the wording in the Summary section could lead to an interpretation that the cause of the reported incident was restrictions in the pilot's elevator input control system. We disagree with revising the section as proposed, because, as stated in the Discussion section of the proposed AD, the design review was conducted as part of an intensive investigation. The investigation was conducted by the National Transportation Safety Board, the FAA, and Boeing. We have revised the Summary section and paragraph (d) of the final rule to state, “This AD results from a report of a restriction in the pilot's elevator input control system. A design review performed on the elevator input torque tube assembly in the course of the investigation discovered possible failure modes that could lead to a jam of the elevator control system.”
Request To Allow Different Procedures for Re-Identification
The commenter, an airplane operator, requests that paragraph (f) be revised to allow alternate methods for re-identifying the modified elevator torque tube assemblies. The commenter explains that the service bulletins referenced in the proposed AD specify the use of a rubber ink stamp method to re-identify the modified assemblies. The commenter points out that operators of a single airplane would have to fabricate or acquire a stamp for a one-time use, and operators of many airplanes would have to acquire dozens of rubber stamps to support the various overhaul facility locations. The commenter requests that the final rule allow for use of either the rubber stamp method, or the use of a pen with indelible ink. The commenter states that the component number could then be covered with protective covering.
We agree with the commenter. The intent of the procedures in the proposed AD and in the service bulletins is to signify that the modification has been accomplished, not to specify the method of re-identification. We have revised paragraph (f) of the final rule to allow alternate permanent part marking in lieu of rubber stamping.Start Printed Page 74648
Clarification of Alternative Method of Compliance (AMOC) Paragraph
We have revised this action to clarify the appropriate procedure for notifying the principal inspector before using any approved AMOC on any airplane to which the AMOC applies.
We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.
Costs of Compliance
There are about 2,971 airplanes of the affected design in the worldwide fleet. This AD will affect about 1,573 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this AD.
|Modification||Work hours||Average labor rate per hour||Parts||Cost per airplane||U.S. registered airplanes||Fleet cost|
|For airplanes identified in Boeing Alert Service Bulletin 737-27A1271 as Group 1||5||$65||$701||$1,026||249||$255,474|
|For airplanes identified in Boeing Alert Service Bulletin 737-27A1271 as Group 2||7||65||1,290||1,745||311||542,695|
|For all airplanes identified in Boeing Alert Service Bulletin 737-27A1274||3||65||50||245||1,013||248,185|
In addition, a special tool is necessary to do the modification required by this AD. Boeing will provide one tool at no charge to each customer regardless of warranty status.
Based on these figures, the estimated total cost of this AD for U.S. operators is about $1,046,354, or between $1,271 and $1,990 per airplane.
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.
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 this AD:
(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.
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.Start List of Subjects
List of Subjects in 14 CFR Part 39
- Air transportation
- Aviation safety
- Incorporation by reference
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:Start Part
PART 39—AIRWORTHINESS DIRECTIVESEnd Part Start Amendment Part
1. The authority citation for part 39 continues to read as follows:End Amendment Part
2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):End Amendment Part
2005-26-03 Boeing: Amendment 39-14424. Docket No. FAA-2005-21712; Directorate Identifier 2005-NM-070-AD.
(a) This AD becomes effective January 20, 2006.
(c) This AD applies to the airplanes identified in Table 1 of this AD, certificated in any category.
|Boeing airplane models—||As identified in Boeing Alert Service Bulletin—|
|737-100, -200, -200C, -300, -400, and -500 series airplanes||737-27A1274, dated February 17, 2005.|
|737-600, -700, -700C, -800 and -900 series airplanes||737-27A1271, dated December 16, 2004.|
(d) This AD results from a report of a restriction in the pilot's elevator input control system. Although the cause of the incident was indeterminate, a design review performed on the elevator input torque tube assembly in the course of the investigation discovered possible failure modes that could lead to a jam of the elevator control system. We are issuing this AD to prevent loss of elevator control and consequent reduced controllability of the airplane.
(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.
(f) Within 60 months after the effective date of this AD: Modify the elevator input torque tube assembly by doing all the actions in accordance with the Accomplishment Instructions of the applicable service bulletin in Table 1 of this AD. Where the applicable service bulletin specifies to re-identify the modified elevator torque tube assemblies using a rubber stamp, the part may be re-identified using a permanent method that is acceptable to the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.
Alternative Methods of Compliance (AMOCs)
(g)(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) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.
Material Incorporated by Reference
(h) You must use Boeing Alert Service Bulletin 737-27A1274, dated February 17, 2005; or Boeing Alert Service Bulletin 737-27A1271, dated December 16, 2004; as applicable, 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 these documents 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 Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov; or at the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.Start Signature
Issued in Renton, Washington, on November 25, 2005.
Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 05-24151 Filed 12-15-05; 8:45 am]
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