
[Federal Register Volume 76, Number 55 (Tuesday, March 22, 2011)]
[Proposed Rules]
[Pages 15864-15867]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-6613]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0254; Directorate Identifier 2010-NM-180-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Model 737-600, -700, 
-700C, -800, -900, and -900ER Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above. For certain airplanes, this proposed AD would 
require a one-time inspection for damage of the hydraulic actuator rod 
ends and actuator attach fittings on the thrust reversers, and repair 
or replacement if necessary. For all airplanes, this proposed AD also 
would require repetitive inspections for damage of the hydraulic 
actuator rod ends, attach bolts, and nuts; repetitive inspections for 
damage of fitting assemblies, wear spacers, and actuator attach 
fittings on the thrust reverser; repetitive measurements of the wear 
spacer; and corrective actions if necessary. This proposed AD was 
prompted by in-service damage of the attachment fittings for the thrust 
reverser actuator. We are proposing this AD to detect and correct such 
damage, which could result in actuator attach fitting failure, loss of 
the thrust reverser auto restow function, and consequent loss of 
control of the airplane.

DATES: We must receive comments on this proposed AD by May 6, 2011.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; phone: 206-
544-5000, extension 1; fax: 206-766-5680; e-mail: me.boecom@boeing.com; 
Internet: https://www.myboeingfleet.com. You may review copies of the 
referenced service information at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information 
on the availability of this material at the FAA, call 425-227-1221.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office

[[Page 15865]]

(phone: 800-647-5527) is in the ADDRESSES section. Comments will be 
available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Chris R. Parker, Aerospace Engineer, 
Propulsion Branch, ANM-140S, Seattle Aircraft Certification Office 
(ACO), FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; 
phone: 425-917-6496; fax: 425-917-6590; e-mail: Chris.R.Parker@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2011-0254; 
Directorate Identifier 2010-NM-180-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    We have received a report indicating that the attachment fittings 
for the thrust reverser actuator have shown in-service wear damage. 
While in the stowed position, the actuator is locked and is in tension. 
The tensile load applied by the locking screw causes the hydraulic 
actuator rod end to rotate. As the hydraulic actuator rod end rotates, 
wear occurs to the bushings in the actuator attach fitting. The 
bushings continue to wear until there is contact directly between the 
hydraulic actuator rod end and the attach fitting. This condition, if 
not detected and corrected, could result in actuator attach fitting 
failure and loss of the thrust reverser auto restow function. Loss of 
the thrust reverser auto restow function removes one of the three 
primary levels of protection against an uncommanded thrust reverser 
deployment. An uncommanded thrust reverser deployment could result in 
loss of airplane control.

Relevant Service Information

    We reviewed Boeing Special Attention Service Bulletin 737-78-1083, 
dated June 30, 2010. For Group 1 airplanes, this service bulletin 
specifies a one-time detailed inspection to detect damage (i.e., wear, 
cracks, nicks, dents, and scratches) of the hydraulic actuator rod ends 
and the actuator attach fittings on the right and left thrust 
reversers.
    For airplanes on which damage is found on a hydraulic actuator rod 
end, this service bulletin specifies replacing of the hydraulic 
actuator rod end assembly with a new hydraulic actuator rod end 
assembly.
    For airplanes on which no damage is found on an actuator attach 
fitting, this service bulletin specifies installing of a new spacer. 
For damage found on an actuator attach fitting that is within stated 
repair limits, this service bulletin specifies repairing the actuator 
attach fitting and installing a new spacer. For damage that exceeds the 
repair limits of the actuator attach fitting, this service bulletin 
specifies replacing the actuator attach fitting with a new actuator 
fitting.
    For both Group 1 and Group 2 airplanes, this service bulletin 
describes procedures for repetitive inspections for damage (as 
specified in each inspection that follows), repetitive measurements, 
and corrective actions if necessary. The inspections and measurement 
include the following:
     A general visual inspection for cracks, nicks, dents, and 
scratches of the fitting assembly
     A detailed inspection for tears, holes, and disbonds of 
the wear spacer
     A measurement of the thickness of the wear spacer
     A detailed inspection for surface damage of the attach 
fitting
     A general visual inspection for damage (i.e. missing, 
cracked, or bent parts) of the rod end, attach bolt, and nut
    The corrective actions include replacing spacers with new spacers, 
repairing attach fittings, replacing attach fittings with new attach 
fittings, replacing the rod end, attach bolt, and nuts with a new 
actuator rod end assembly.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would require accomplishing the actions specified 
in the service information described previously, except as discussed 
under ``Differences Between the Proposed AD and the Service 
Information.''

Differences Between the Proposed AD and the Service Information

    Appendix A of Boeing Special Attention Service Bulletin 737-78-
1083, dated June 30, 2010, specifies a general visual inspection for 
cracks, nicks, dents, and scratches of the fitting assembly. We have 
determined that this inspection is accomplished during the detailed 
inspections specified in Appendix A of Boeing Special Attention Service 
Bulletin 737-78-1083, dated June 30, 2010.
    Appendix A of Boeing Special Attention Service Bulletin 737-78-
1083, dated June 30, 2010, specifies to replace missing, cracked, and 
bent rod ends, attach bolts, and nuts, but does not specify replacement 
parts and how to replace the affected part. This proposed AD would 
require replacing missing, cracked, and bent rod ends, attach bolts, 
and nuts with new parts in accordance with a method approved by the 
FAA.

Costs of Compliance

    We estimate that this proposed AD will affect 1,070 airplanes of 
U.S. registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated costs
----------------------------------------------------------------------------------------------------------------
                                                                                                Cost on U.S.
              Action                    Labor cost        Parts cost    Cost per product          operators
----------------------------------------------------------------------------------------------------------------
One-time detailed inspection and   28 work-hours x $85           $68  $2,448..............  $2,080,800.
 installation (Group 1: 850         per hour = $2,380.
 airplanes).
General visual and detailed        23 work-hours x $85             0  $1,955 per            $2,091,850 per
 inspections (Group 1 and 2         per hour = $1,955                  inspection cycle.     inspection cycle.
 airplanes).                        per inspection
                                    cycle.
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[[Page 15866]]

    We estimate the following costs to do any necessary repairs or 
replacements that would be required based on the results of the 
proposed inspection. These on-condition costs are based on all the 
thrust reverser attachment fittings needing repair or replacement. We 
have no way of determining the number of aircraft that might need these 
repairs or replacements.

                           On-Condition Costs
------------------------------------------------------------------------
                                                               Cost per
            Action                Labor cost     Parts cost    product
------------------------------------------------------------------------
Attach fitting replacement...  75 work-hours x      $10,850      $17,225
                                $85 per hour =
                                $6,375.
------------------------------------------------------------------------

    According to the manufacturer, some of the costs of this proposed 
AD may be covered under warranty, thereby reducing the cost impact on 
affected individuals. We do not control warranty coverage for affected 
individuals. As a result, we have included all costs in our cost 
estimate.

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 determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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.


Sec.  39.13  [Amended]

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

The Boeing Company: Docket No. FAA-2011-0254; Directorate Identifier 
2010-NM-180-AD.

Comments Due Date

    (a) We must receive comments by May 6, 2011.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to The Boeing Company Model 737-600, -700, -
700C,-800, -900, and -900ER series airplanes, certificated in any 
category, as identified in Boeing Special Attention Service Bulletin 
737-78-1083, dated June 30, 2010.

Subject

    (d) Joint Aircraft System Component (JASC)/Air Transport 
Association (ATA) of America Code 78, Exhaust.

Unsafe Condition

    (e) This AD was prompted by in-service damage of the attachment 
fittings for the thrust reverser actuator. We are issuing this AD to 
detect and correct such damage, which could result in actuator 
attach fitting failure, loss of the thrust reverser auto restow 
function, and consequent loss of control of the airplane.

Compliance

    (f) Comply with this AD within the compliance times specified, 
unless already done.

Inspection and Repair: Group 1 Airplanes

    (g) For Group 1 airplanes, as identified in Boeing Special 
Attention Service Bulletin 737-78-1083, dated June 30, 2010: At the 
compliance time specified in paragraph (g)(1) or (g)(2) of this AD, 
whichever is later, perform a one-time detailed inspection to detect 
wear, cracks, nicks, dents, and scratches of the hydraulic actuator 
rod ends and actuator attach fittings on the thrust reversers, in 
accordance with the Accomplishment Instructions of Boeing Special 
Attention Service Bulletin 737-78-1083, dated June 30, 2010.
    (1) Within 7,500 flight hours after the effective date of this 
AD.
    (2) Before the accumulation of 15,000 total flight cycles or 
30,000 total flight hours, whichever occurs first.
    (h) If any wear, crack, nick, dent, or scratch of any hydraulic 
actuator rod end is found during the inspection required by 
paragraph (g) of this AD: Before further flight, replace the 
affected hydraulic actuator rod end assembly with a new hydraulic 
actuator rod end assembly, in accordance with the Accomplishment 
Instructions of Boeing Special Attention Service Bulletin 737-78-
1083, dated June 30, 2010.
    (i) If no wear, cracks, nicks, dents, and scratches of any 
actuator attach fittings are found during the inspection required by 
paragraph (g) of this AD: Before further flight, install new wear 
spacers on the affected actuator attach fitting, in accordance with 
the Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 737-78-1083, dated June 30, 2010.
    (j) If any wear, crack, nick, dent, or scratch of any actuator 
attach fitting is found during the inspection required by paragraph 
(g) of this AD, and is less than 0.005 inch in depth: Before further 
flight, repair the affected actuator attach fitting and install the 
new wear spacer, in accordance with the Accomplishment Instructions 
of Boeing Special Attention Service Bulletin 737-78-1083, dated June 
30, 2010.
    (k) If any wear, crack, nick, dent, or scratch of any actuator 
attach fitting is found during the inspection required by paragraph 
(g) of this AD, and is 0.005 inch or greater in depth: Before 
further flight, replace the actuator attach fitting with a new 
actuator attach fitting, in accordance with the Accomplishment 
Instructions of Boeing

[[Page 15867]]

Special Attention Service Bulletin 737-78-1083, dated June 30, 2010.

Repetitive Inspections and Corrective Actions

    (l) For Group 1 airplanes, as identified in Boeing Special 
Attention Service Bulletin 737-78-1083, dated June 30, 2010: Within 
7,500 flight hours after accomplishing the requirements of paragraph 
(g) of this AD, do the actions specified in paragraphs (l)(1), 
(l)(2), (l)(3), and (l)(4) of this AD. Repeat the actions thereafter 
at intervals not to exceed 7,500 flight hours.
    (1) Do a detailed inspection for tears, holes, and disbonds of 
the wear spacer, in accordance with Appendix A of Boeing Special 
Attention Service Bulletin 737-78-1083, dated June 30, 2010. If any 
tear, hole, or disbond is found, before further flight, replace the 
spacer with a new spacer, in accordance with Appendix A of Boeing 
Special Attention Service Bulletin 737-78-1083, dated June 30, 2010.
    (2) Measure the thickness of the wear spacer in accordance with 
Appendix A of Boeing Special Attention Service Bulletin 737-78-1083, 
dated June 30, 2010. If the thickness is less than 0.020 inch, 
before further flight, replace the spacer with a new spacer, in 
accordance with Appendix A of Boeing Special Attention Service 
Bulletin 737-78-1083, dated June 30, 2010.
    (3) Do a detailed inspection for surface damage of the attach 
fitting, in accordance with Appendix A of Boeing Special Attention 
Service Bulletin 737-78-1083, dated June 30, 2010.
    (i) If the surface damage is less than 0.005 inch depth, before 
further flight, repair the attach fitting, in accordance with 
Appendix A of Boeing Special Attention Service Bulletin 737-78-1083, 
dated June 30, 2010.
    (ii) If the surface damage is 0.005 inch or greater in depth, 
before further flight, replace the attach fitting with a new attach 
fitting, in accordance with Appendix B of Boeing Special Attention 
Service Bulletin 737-78-1083, dated June 30, 2010.
    (4) Do a general visual inspection for damage (i.e. wear, 
missing, cracked, or bent parts) of the rod end, attach bolt, and 
nut, in accordance with Appendix A of Boeing Special Attention 
Service Bulletin 737-78-1083, dated June 30, 2010. If any damage is 
found, before further flight, replace the affected part with a new 
part in accordance with a method approved by the Manager, Seattle 
Aircraft Certification Office (ACO), FAA.

Group 2 Inspection and Repair

    (m) For Group 2 airplanes, as identified in Boeing Special 
Attention Service Bulletin 737-78-1083, dated June 30, 2010: Within 
12 months after the effective date of this AD, perform the actions 
required in paragraph (l) of this AD. Repeat the actions thereafter 
at intervals not to exceed 7,500 flight hours.

 Alternative Methods of Compliance (AMOCs)

    (n)(1) The Manager, Seattle Aircraft Certification Office, FAA, 
has the authority to approve AMOCs for this AD, if requested using 
the procedures found in 14 CFR 39.19. In accordance with 14 CFR 
39.19, send your request to your principal inspector or local Flight 
Standards District Office, as appropriate. If sending information 
directly to the manager of the ACO, send it to the attention of the 
person identified in the Related Information section of this AD. 
Information may be e-mailed to 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

Related Information

    (o) For more information about this AD, contact Chris R. Parker, 
Aerospace Engineer, Propulsion Branch, ANM-140S, Seattle Aircraft 
Certification Office (ACO), FAA, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; phone: 425-917-6496; fax: 425-917-6590; e-
mail: Chris.R.Parker@faa.gov.
    (p) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P. O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; phone: 
206-544-5000, extension 1; fax: 206-766-5680;e-mail: 
me.boecom@boeing.com; Internet:https://www.myboeingfleet.com. You 
may review copies of the referenced service information at the FAA, 
Transport Airplane Directorate, the FAA, 1601 Lind Avenue, SW., 
Renton, Washington. For information on the availability of this 
material at the FAA, call 425-227-1221.

    Issued in Renton, Washington, on March 14, 2011.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-6613 Filed 3-21-11; 8:45 am]
BILLING CODE 4910-13-P


