[Federal Register Volume 67, Number 172 (Thursday, September 5, 2002)]
[Rules and Regulations]
[Pages 56750-56753]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-22177]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-344-AD; Amendment 39-12874; AD 2002-18-02]
RIN 2120-AA64


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 adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 737-100, -200, -200C, -300, -400, 
and -500 series airplanes, that requires a one-time inspection to 
determine whether the lower bearing support of the aileron transfer 
mechanism directly below the first officer's control column has a 
``pocket,'' and follow-on corrective actions, if necessary. The actions 
specified by this AD are intended to prevent jamming of the first 
officer's control wheel due to the presence of a foreign object on the 
lower bearing support of the transfer mechanism, which could result in 
reduced controllability of the airplane. This action is intended to 
address the identified unsafe condition.

DATES: Effective October 10, 2002.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 10, 2002.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, PO 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: Technical Information: Doug Tsuji, 
Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-1506; fax (425) 227-1181.
    Other Information: Sandi Carli, Airworthiness Directive Technical 
Editor/Writer; telephone (425) 687-4243, fax (425) 227-1232. Questions 
or comments may also be sent via the

[[Page 56751]]

Internet using the following address: [email protected]. Questions or 
comments sent via the Internet as attached electronic files must be 
formatted in Microsoft Word 97 for Windows or ASCII text.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 737-100, -
200, -200C, -300, -400, and -500 series airplanes was published in the 
Federal Register on February 11, 2002 (67 FR 6212). That action 
proposed to require a one-time inspection to determine whether the 
lower bearing support of the aileron transfer mechanism directly below 
the first officer's control column has a ``pocket,'' and follow-on 
corrective actions, if necessary.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposed AD

    One commenter fully supports the proposed actions.

Request To Revise Cost Impact

    Two commenters (the manufacturer and an operator) request that the 
proposed AD be revised to include estimated costs necessary to replace 
the lower bearing support, which would be required if a pocket is 
found. The commenters consider this information important in this case 
although they recognize that such conditional requirements are not 
always included in the Cost Impact section of AD actions. The operator 
cites existing AD 2002-04-08, amendment 39-12665 (67 FR 9395, March 1, 
2002), as an example of an AD that does include costs associated with 
correcting a discrepant condition. Although the replacement is not 
mandatory on all airplanes (i.e., not all airplanes will have the 
discrepant condition), the commenters expect a considerable number of 
airplanes to have a pocket on the lower bearing support, requiring 
replacement. The operator adds that, based on service experience, a 
more realistic work-hour estimate is 20 to 28 work hours, rather than 
the 8.5 work hours specified by the alert service bulletin.
    The FAA partially agrees. Because the discrepant condition is 
expected to be found on a considerable number of airplanes, the FAA 
recognizes that information regarding the estimated cost to replace the 
lower bearing support would be helpful for operators in planning and 
scheduling the work. The Cost Impact section in the final rule has been 
revised accordingly. However, those costs may vary from operator to 
operator based on work hours required; this AD reflects the work hour 
estimate specified in Boeing Alert Service Bulletin 737-27A1238, 
described in the proposed AD.

Request To Revise Compliance Time for Follow-on Actions

    Boeing requests an extension of the proposed compliance time for 
the follow-on actions specified by paragraph (b) of the proposed AD. As 
stated, that paragraph would have required replacement or modification 
of the lower bearing support before further flight after a pocket is 
detected. Boeing suggests that a period of 3 months (after a pocket is 
detected) will satisfy the intent of the proposed AD and allow 
operators adequate time to order the parts and schedule the work. 
Boeing adds that the presence of a pocket by itself does not cause the 
first officer's control wheel to jam.
    The FAA agrees with Boeing's request and rationale to extend the 
compliance time. In further justification, the FAA notes that there are 
system overrides between the captain's and first officer's control 
wheels that allow for aileron control if the first officer's control 
wheel jams. In light of this situation, and in consideration of the 
Model 737 service history, the FAA has determined that allowing 3 
months to initiate the required follow-on actions will accommodate the 
time necessary for affected operators to order, obtain, and install the 
required parts--without adversely affecting safety. The compliance time 
in paragraph (b) of the final rule has been revised accordingly.

Request To Revise Certain Conditional Requirements

    Boeing requests that the proposed corrective action for cracking 
and non-normal resistance (paragraph (c) of the proposed AD) be revised 
to cite specific methods of repair, rather than requiring FAA approval 
for repair methods. Boeing suggests that the FAA require that any 
cracked bearing support be replaced with a new, improved part; and that 
any non-normal resistance be fixed according to established Boeing 
Aircraft Maintenance Manual (AMM) procedures. Boeing suggests this 
change may reduce the delays often associated with pending FAA approval 
of repair methods.
    The FAA agrees with the request, finding that procedures in the 
alert service bulletin and AMM adequately define the necessary follow-
on corrective actions. Directing operators to these specific references 
for corrective action will reduce the workload for operators and the 
FAA by eliminating the need to request and approve alternative methods 
of compliance. The final rule has been revised to require replacement 
of cracked bearing supports according to the alert service bulletin and 
repair of any non-normal resistance according to the Boeing 737 AMM.

Request To Revise Spares Paragraph

    One commenter requests that paragraph (d) (``Spares'') of the 
proposed AD be revised to distinguish actions that apply to the ``lower 
bearing support'' from those that apply to the ``aileron transfer 
mechanism'' (the higher level assembly of the bearing support). 
According to the commenter, the part numbers (P/Ns) for the aileron 
transfer mechanism (P/Ns 65-54200-6 through -8), using lower bearing 
supports (P/N 65-55476-1 or 65-55476-9), should also be prohibited from 
installation after the effective date of the AD. The commenter adds 
that the alert service bulletin does not provide instructions for 
accomplishing the inspection and corrective action for the higher 
assembly aileron transfer mechanisms. The operator states that 
operators' inventory tracking systems may not track the lower-level (P/
N 65-55476-1 or 65-55476-9) lower bearing supports, but will track the 
higher assembly (P/Ns 65-54200-6 through -8) aileron transfer 
mechanisms. The commenter notes that it is possible that higher 
assembly aileron transfer mechanisms with lower bearing supports with 
pockets may be installed in airplanes.
    The FAA does not agree with the request to revise paragraph (d) of 
this AD. The Boeing Component Maintenance Manuals (CMMs) and 
Illustrated Parts Catalogs (IPCs) show that a lower bearing support 
having P/N 65-55476-9 is used on aileron transfer mechanisms having P/
Ns 65-54200-6 through -8. The FAA finds that, even if some operators' 
tracking systems did not list the 65-55476 ``dash'' numbers, those 
operators would find them in the CMMs and IPCs. The intent of paragraph 
(d) of the AD is to prohibit the lower bearing supports (P/Ns 65-55476-
1 and 65-55476-9) from being installed after the effective date of the 
AD. No change to the final rule is necessary in this regard.

Clarification of Modification Requirements

    After reviewing paragraph (b) of the proposed AD, the FAA finds it

[[Page 56752]]

necessary to distinguish the actions associated with the modification 
from those associated with the optional bearing support replacement. 
The final rule separates paragraph (b)(1) into two subparagraphs to 
reflect the two options, and clarifies in paragraph (b)(2) that follow-
on actions must be done following either the modification or the 
replacement.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 3,101 Boeing Model 737-100, -200, -200C, -
300, -400, and -500 series airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 1,244 airplanes of U.S. 
registry will be affected by this AD, that it will take approximately 1 
work hour per airplane to accomplish the required inspection, and that 
the average labor rate is $60 per work hour. Based on these figures, 
the cost impact of this AD on U.S. operators is estimated to be 
$74,640, or $60 per airplane.
    The cost impact figure discussed above is 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.
    If a lower bearing support is found to have a pocket, the FAA 
estimates that it will take about 9 work hours per airplane to remove 
the discrepant parts and replace them with acceptable parts. Required 
replacement parts would cost an estimated $931. Based on these figures, 
the cost impact of this AD is estimated to be increased by $1,471 for 
an airplane having a pocket.

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 adding the following new 
airworthiness directive:

2002-18-02 Boeing: Amendment 39-12874. Docket 2001-NM-344-AD.

    Applicability: Model 737-100, -200, -200C, -300, -400, and -500 
series airplanes; line numbers 1 through 3132 inclusive; 
certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (e) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent jamming of the first officer's control wheel due to 
the presence of a foreign object on the lower bearing support of the 
transfer mechanism for the aileron, which could result in reduced 
controllability of the airplane, accomplish the following:

Detailed Inspection

    (a) Within 2 years after the effective date of this AD, do a 
one-time detailed inspection to determine whether the lower bearing 
support of the aileron transfer mechanism directly below the first 
officer's control column has a ``pocket,'' according to Boeing Alert 
Service Bulletin 737-27A1238, dated July 13, 2000. (The upper 
surface has a raised stop at the end opposite the rig pin hole.) If 
no pocket is found, no further action is required by this AD.

    Note 2: ``Pocket'' is the term given to the area on the upper 
surface of the lower bearing support, aft of the bearing in the area 
of the rig pin holes, that is surrounded by the ribs of the lower 
bearing support.


    Note 3: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

Follow-On Actions

    (b) If a pocket is found on the lower bearing support of the 
transfer mechanism for the aileron during the inspection required by 
paragraph (a) of this AD: Within 3 months after the inspection, do 
paragraphs (b)(1) and (b)(2) of this AD according to Boeing Alert 
Service Bulletin 737-27A1238, dated July 13, 2000, except as 
provided by paragraph (c) of this AD.
    (1) Do the actions specified by either paragraph (b)(1)(i) or 
(b)(1)(ii) of this AD.
    (i) Do all actions associated with the modification of the ribs 
of the lower bearing support (including performing a dye-penetrant 
inspection for cracking of the lower bearing support and any 
necessary corrective actions, machining the ribs, and changing the 
part number of the lower bearing support); or
    (ii) Replace the lower bearing support with a new, improved 
support.
    (2) Do the follow-on actions to the modification or replacement 
required by paragraph (b)(1) of this AD, including a functional test 
of the transfer mechanism, a test of the aileron control mechanism 
for interference, and corrective actions, if necessary.

Corrective Actions

    (c) If any cracking of the lower bearing support is found during 
the dye-penetrant inspection specified in paragraph (b)(1)(i) of 
this AD: Before further flight, replace the cracked part either with 
a new part that does not have a pocket or with a reworked, crack-
free part, according to Boeing Alert Service

[[Page 56753]]

Bulletin 737-27A1238, dated July 13, 2000. If any resistance is 
found during the test of the aileron control mechanism required by 
paragraph (b)(2) of this AD: Before further flight, fix the 
resistance according to established Boeing 737 Aircraft Maintenance 
Manual procedures.

Spares

    (d) As of the effective date of this AD, no person may install a 
lower bearing support, part number 65-55476-1 or 65-55476-9, on any 
airplane, unless the actions specified in paragraphs (a), (b), and 
(c) of this AD, as applicable, have been accomplished.

Alternative Methods of Compliance

    (e) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Seattle ACO.

    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (f) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

Incorporation by Reference

    (g) Except as required by paragraph (c) of this AD: The actions 
shall be done in accordance with Boeing Alert Service Bulletin 737-
27A1238, dated July 13, 2000. This incorporation by reference was 
approved by the Director of the Federal Register in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from 
Boeing Commercial Airplane Group, PO 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

    (h) This amendment becomes effective on October 10, 2002.

    Issued in Renton, Washington, on August 26, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-22177 Filed 9-4-02; 8:45 am]
BILLING CODE 4910-13-P