FR Doc 05-24151

[Federal Register: December 16, 2005 (Volume 70, Number 241)]
[Rules and Regulations]
[Page 74647-74649]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16de05-4]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21712; Directorate Identifier 2005-NM-070-AD;
Amendment 39-14424; AD 2005-26-03]
RIN 2120-AA64

Airworthiness Directives; Boeing Model 737 Airplanes

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

ACTION: Final rule.

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SUMMARY: 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.

DATES: 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.

ADDRESSES: 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.

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.

SUPPLEMENTARY 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.

Discussion

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.

Comments

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.

[[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.

Conclusion

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.

Estimated Costs
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U.S.
Modification Work hours Average labor Parts Cost per registered Fleet cost
rate per hour airplane airplanes
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For airplanes identified in Boeing Alert Service 5 $65 $701 $1,026 249 $255,474
Bulletin 737-27A1271 as Group 1........................
For airplanes identified in Boeing Alert Service 7 65 1,290 1,745 311 542,695
Bulletin 737-27A1271 as Group 2........................
For all airplanes identified in Boeing Alert Service 3 65 50 245 1,013 248,185
Bulletin 737-27A1274...................................
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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.

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 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.

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

0
1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

0
2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by
adding the following new airworthiness directive (AD):

2005-26-03 Boeing: Amendment 39-14424. Docket No. FAA-2005-21712;
Directorate Identifier 2005-NM-070-AD.

Effective Date

(a) This AD becomes effective January 20, 2006.

Affected ADs

(b) None.

Applicability

Table 1.--Airplanes Affected by This AD
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As identified in Boeing Alert
Boeing airplane models-- Service Bulletin--
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737-100, -200, -200C, -300, -400, and - 737-27A1274, dated February 17,
500 series airplanes. 2005.
737-600, -700, -700C, -800 and -900 737-27A1271, dated December 16,
series airplanes. 2004.
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[[Page 74649]]

Unsafe Condition

(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.

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.

Modification

(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 Sec.
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.

Issued in Renton, Washington, on November 25, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-24151 Filed 12-15-05; 8:45 am]

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