[Federal Register Volume 72, Number 153 (Thursday, August 9, 2007)]
[Rules and Regulations]
[Pages 44744-44746]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-15220]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-18814; Directorate Identifier 2003-NM-286-AD; 
Amendment 39-15144; AD 2007-16-05]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
300, -400, and -500 Series 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 all 
Boeing Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. This AD requires repetitive inspections for discrepancies of 
the elevator tab control rod assemblies and/or damage to the 
surrounding structure, and related corrective action. This AD results 
from reports indicating loose jam nuts and/or thread wear at the rod 
ends on the elevator tab control rod assembly. We are issuing this AD 
to find and fix discrepancies of the elevator tab control rod assembly, 
which could result in excessive freeplay in the elevator tab control 
rods. Such freeplay could cause loss of both load paths, subsequent 
elevator tab flutter, and consequent reduced structural integrity and 
loss of controllability of the airplane.

DATES: This AD becomes effective September 13, 2007.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of September 13, 
2007.

ADDRESSES: You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue, SE., 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: Kenneth Frey, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone (425) 917-6468; 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 Operations 
office between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Operations office (telephone (800) 647-5527) is 
located on the ground floor of the West 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 all Boeing Model 737-
100, -200, -200C, -300, -400, and -500 series airplanes. The NPRM was 
published in the Federal Register on August 10, 2004 (69 FR 48424). 
That NPRM proposed to require repetitive inspections for discrepancies 
of the elevator tab control rod assemblies and/or damage to the 
surrounding structure, and related corrective action.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments that have been 
submitted on the NPRM.

Supportive Comments

    Airline Pilots Association International concurs with the NPRM and 
the proposed implementation schedule therein.
    Air Transport Association (ATA) and Alaska Airlines (Alaska) 
generally support the intent of the AD.
    ATA, on behalf of its member, Alaska, states that the inspection 
action specified in the NPRM is acceptable provided there are adequate 
parts available for replacement when discrepancies are discovered. 
Alaska adds that the proposed compliance intervals and repeat 
inspections are acceptable as proposed, as they will allow compliance 
at heavy check maintenance visits. We have verified with Boeing that 
adequate replacement parts are available.

Request To Revise Service Information

    Jet Airways asks that the FAA advise Boeing to revise the 
referenced service bulletin. Jet Airways states that since there is a 
difference between the NPRM and the service bulletin, in that the 
service bulletin recommends a one-time inspection of the control rod 
tab assemblies and the NPRM requires repetitive inspections, the 
service bulletin should be revised to include the repetitive 
inspections.
    We agree with Jet Airways for the reasons provided. Since we issued 
the NPRM, Boeing has issued Alert Service Bulletin 737-27A1266, 
Revision 1, dated January 2, 2007. The procedures in Revision 1 are 
essentially the same as those in the original issue of the service 
bulletin; however, Revision 1 clarifies procedures for visually 
inspecting for the presence of inspection putty on each jam nut and 
ensuring that the inspection putty is intact and is not cracked or 
damaged. In addition, the one-time inspection for discrepancies of the 
elevator tab control rod assemblies and/or damage to the surrounding 
structure was changed to repetitive inspections. Therefore, Revision 1 
eliminates the difference between this AD and the service bulletin that 
was noted in the NPRM. We have changed paragraph (f) of this AD to 
refer to Revision 1 and give credit for inspections and corrective 
action accomplished using the original issue of Boeing Alert Service 
Bulletin 737-27A1266, dated September 18, 2003.

Request for Locking Provision for Control Rod Jam Nuts

    Jet Airways also states that the repetitive inspection requirement 
is only needed because there is no locking provision for the jam nuts. 
Jet Airways

[[Page 44745]]

adds that the FAA and Boeing should develop a provision for 
installation of lockwire to avoid looseness of the jam nuts and to 
terminate the repetitive inspection requirement.
    We partially agree with Jet Airways, as follows:
    We agree that locking provisions for certain elevator tab control 
rods with lockwire might be beneficial; however, we do not agree that 
the repetitive inspection requirement is needed only because there is 
no locking provision for the jam nuts. Repetitive inspections of the 
elevator control tab assemblies will identify discrepancies of the 
inspection putty, loose jam nuts, worn threads, and damage to 
surrounding structure that resulted from improperly torqued jam nuts. 
As previously described, Revision 1 of the service bulletin clarifies 
procedures for visually inspecting for the presence of inspection putty 
on each jam nut and ensuring that the inspection putty is intact and is 
not cracked or damaged. We have made no change to the AD in this 
regard.

Request To Change Description of the Unsafe Condition

    Boeing states that the unsafe condition, as specified in the NPRM, 
is incorrect. That unsafe condition states, ``We are proposing this AD 
to find and fix excessive freeplay in the tab control mechanism, which 
could result in elevator tab flutter and consequent loss of 
controllability of the airplane.'' Boeing states that there is no 
freeplay check identified in the procedure specified in the referenced 
service information. Boeing asks that the wording be changed to read, 
``We are proposing this AD to prevent excessive thread wear in the rod 
ends of the elevator tab control rods as a result of loose jam nuts. 
Excessive rod end thread wear results in increased freeplay in the 
elevator tab control loop. Airframe vibration can occur with sufficient 
freeplay, leading to a degradation of handling characteristics of the 
airplane.''
    Boeing also asks that the unsafe condition, as specified in the 
Discussion section of the NPRM, be changed for the same reason to read, 
``Excessive freeplay in the elevator tab control rods, if not found and 
fixed, could result in the loss of both load paths, leading to elevator 
tab flutter and consequent loss of controllability of the airplane.''
    We agree to change the description of the unsafe condition because 
Boeing is accurate in the statement that there is no freeplay check 
identified in the procedure specified in the referenced service 
bulletin. We have changed the description of the unsafe condition to 
read, ``We are issuing this AD to find and fix discrepancies of the 
elevator tab control rod assembly, which could result in excessive 
freeplay in the elevator tab control rods. Such freeplay could cause 
loss of both load paths, subsequent elevator tab flutter, and 
consequent reduced structural integrity and loss of controllability of 
the airplane.'' We have changed the wording for the unsafe condition to 
include the intent of the information provided by Boeing. The 
discrepancies (loose jam nuts and/or thread wear at the rod ends) are 
referred to in the sentence immediately preceding the unsafe condition 
and do not need to be repeated. Concerning Boeing's comment on the 
Discussion section of the NPRM, since that section of the preamble does 
not reappear in the final rule, no change to the AD is necessary.

Clarification of Alternative Method of Compliance (AMOC) Paragraph

    We have revised this AD 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 2,878 airplanes of the affected design in the 
worldwide fleet. This AD affects about 1,078 airplanes of U.S. 
registry. The inspection takes about 2 work hours per airplane, at an 
average labor rate of $80 per work hour. Based on these figures, the 
estimated cost of the AD for U.S. operators is $172,480, or $160 per 
airplane, per inspection cycle.

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

0
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 FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2007-16-05 Boeing: Amendment 39-15144. Docket No. FAA-2004-18814; 
Directorate Identifier 2003-NM-286-AD.

Effective Date

    (a) This AD becomes effective September 13, 2007.

Affected ADs

    (b) None.

[[Page 44746]]

Applicability

    (c) This AD applies to all Boeing Model 737-100, -200, -200C, -
300, -400, and -500 series airplanes; certificated in any category.

Unsafe Condition

    (d) This AD results from reports indicating loose jam nuts and/
or thread wear at the rod ends on the elevator tab control rod 
assembly. We are issuing this AD to find and fix discrepancies of 
the elevator tab control rod assembly, which could result in 
excessive freeplay in the elevator tab control rods. Such freeplay 
could cause loss of both load paths, subsequent elevator tab 
flutter, and consequent reduced structural integrity and loss of 
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.

Repetitive Inspections

    (f) Within 4,500 flight cycles or 6,000 flight hours after the 
effective date of this AD, whichever is first: Do a detailed 
inspection for discrepancies of the inspection putty of the elevator 
tab control rod assemblies and/or damage to the surrounding 
structure, by doing all the actions, including all applicable 
related corrective actions, as specified in paragraph 3.B. of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
27A1266, Revision 1, dated January 2, 2007. Do all applicable 
related corrective actions before further flight, in accordance with 
the service bulletin. Repeat the inspection thereafter at intervals 
not to exceed 4,500 flight cycles or 6,000 flight hours, whichever 
is first. Actions accomplished before the effective date of this AD 
in accordance with Boeing Alert Service Bulletin 737-27A1266, dated 
September 18, 2003, are considered acceptable for compliance with 
the corresponding actions specified in this paragraph.

    Note 1: For the purposes of this AD, a detailed inspection is: 
``An intensive examination of a specific item, installation, or 
assembly to detect damage, failure, or irregularity. Available 
lighting is normally supplemented with a direct source of good 
lighting at an intensity deemed appropriate. Inspection aids such as 
mirror, magnifying lenses, etc., may be necessary. Surface cleaning 
and elaborate procedures may be required.''

Alternative Methods of Compliance (AMOCs)

    (g)(1) The Manager, Seattle Aircraft Certification Office, 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

    (h) You must use Boeing Alert Service Bulletin 737-27A1266, 
Revision 1, dated January 2, 2007, 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 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/cfr/ibr-locations.html.

    Issued in Renton, Washington, on July 30, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-15220 Filed 8-8-07; 8:45 am]
BILLING CODE 4910-13-P