
[Federal Register Volume 77, Number 127 (Monday, July 2, 2012)]
[Rules and Regulations]
[Pages 39153-39156]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-15898]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0673; Directorate Identifier 2012-NM-091-AD; 
Amendment 39-17109; AD 2012-13-07]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for all The 
Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. This AD requires inspecting parts or doing a records review 
to determine if certain trailing edge flap carriages are installed, 
doing repetitive inspections for corrosion, and flaking or missing 
thermal coating on suspect carriage spindles, and related investigative 
and corrective actions, if necessary; this AD also provides optional 
terminating action for the repetitive inspections. This AD was prompted 
by reports of corrosion found on carriage that are located on the 
outboard flaps. We are issuing this AD to detect and correct corrosion 
of the carriage spindle, which could result in a fracture; fracture of 
both the inboard and outboard carriage spindles, at the forward ends 
through the large diameters, on a single flap assembly, could adversely 
affect the continued safe flight and landing of the airplane.

DATES: This AD is effective July 17, 2012.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of July 17, 2012.
    We must receive comments on this AD by August 16, 2012.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, 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: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    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; telephone 206-544-5000, 
extension 1; fax 206-766-5680; 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 AD, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Office (phone: 800-647-5527) is in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Nancy Marsh, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: (425) 917-
6440; fax: (425) 917-6590; email: Nancy.Marsh@faa.gov.

SUPPLEMENTARY INFORMATION: 

Discussion

    We received reports of corrosion found on carriages that are 
located on the outboard flaps. Each of the suspect carriages had 
accumulated fewer than 7,000 total flight cycles. The suspect carriages 
had tungsten-carbide-cobalt-chrome coating applied with high velocity 
oxygenated fuel (HVOF) thermal coating on the spindle. The HVOF thermal 
coating had flaked off the lower surface of the spindle, at the root of 
the spindle. Cracked, flaking, or missing thermal coating can lead to 
moisture ingress, which might begin corroding the alloy steel base 
metal. Corrosion pits in this area could create a stress concentration 
where a crack can start in the base metal, resulting in the inability 
of the carriage to sustain limit load. Corrosion of the carriage 
spindle, if not detected and corrected, could result in fracture of the 
spindle. One fractured carriage spindle on a flap can be compensated 
for with pilot inputs to the aileron or rudder (increasing pilot 
workload). However, fracture of both the inboard and outboard carriage 
spindles, at the forward ends through the large diameters, on a single 
flap, could adversely affect the continued safe flight and landing of 
the airplane.

Relevant Service Information

    We reviewed Boeing Alert Service Bulletin 737-57A1319, dated April 
16, 2012, as revised by Boeing Alert Service Bulletin 737-57A1319, 
Revision 1, dated June 6, 2012. This service information describes the 
following procedures.
     For all airplanes, inspection of parts or review of 
maintenance records to determine if a carriage, i.e., a carriage with 
HVOF thermal coating, is installed at wing butt line (WBL) 254 or WBL 
355.
     For any suspect carriage or carriage with an 
unidentifiable part number (P/N): Repetitive detailed inspections for 
corrosion, missing, or flaking thermal coating on the forward end of 
the carriage spindle at the root (with the option to do a borescope 
inspection instead), and related investigative and corrective actions 
if necessary.
     Related investigative action is a detailed inspection for 
corrosion inhibiting compound (CIC) coverage on the lower surface of 
the spindle at the root.
     The corrective actions include applying or reapplying CIC, 
and replacing the suspect carriage with a new or serviceable carriage.
     Replacement of the suspect carriage with a new or 
serviceable non-HVOF thermal coated carriage eliminates the need for 
the repetitive inspections for that carriage only.

[[Page 39154]]

FAA's Determination

    We are issuing 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.

AD Requirements

    This AD requires accomplishing the actions specified in the service 
information described previously.

Interim Action

    We consider this AD interim action. The manufacturer is currently 
developing a modification that will address the unsafe condition 
identified in this AD. Once this modification is developed, approved, 
and available, we might consider additional rulemaking.

FAA's Justification and Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD. The FAA has found that the risk to the flying public justifies 
waiving notice and comment prior to adoption of this rule because 
corrosion occurring on the exposed base metal can quickly lead to 
cracking and full fracture of the carriage spindle. Fracture of both 
the inboard and outboard carriage spindles, in the forward ends through 
the large diameters, on a single flap, could adversely affect the 
continued safe flight and landing of the airplane. Because of our 
requirement to promote safe flight of civil aircraft and thus, the 
critical need to assure the structural integrity of the carriage 
spindle and the short compliance time involved with this action, this 
AD must be issued immediately. Therefore, we find that notice and 
opportunity for prior public comment are impracticable and that good 
cause exists for making this amendment effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment. However, we invite you to send any written data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include the docket number FAA-2012-0673 and 
Directorate Identifier 2012-NM-091-AD at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this AD. We will 
consider all comments received by the closing date and may amend this 
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 AD.

Costs of Compliance

    We estimate that this AD affects 494 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                           Cost per      Number of U.S.    Cost on U.S.
                               Action                                   Labor cost       Parts cost        product         operators        operators
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspection or records review to determine installation of suspect     1 work-hour x               $0              $85              494          $41,990
 carriage..........................................................  $85 per hour =
                                                                                $85
--------------------------------------------------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary actions that 
would be required based on the results of the inspection. We have no 
way of determining the number of aircraft that might need these 
actions.

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
            Action                  Labor cost         Parts cost                  Cost per product
----------------------------------------------------------------------------------------------------------------
Inspection of suspect           3 work-hours x     $0...............  $255 per inspection cycle.
 carriages.                      $85 per hour =
                                 $255 per
                                 inspection cycle.
Replacement of carriage         17 work-hours x    We have received   $1,445.
 spindle, per spindle (four      $85 per hour =     no definitive
 spindles per airplane).         $1,445.            data that would
                                                    enable us to
                                                    provide a cost
                                                    estimate for
                                                    parts necessary
                                                    for the
                                                    replacement
                                                    specified in
                                                    this AD.
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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

    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:

[[Page 39155]]

    (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),
    (3) Will not affect intrastate aviation in, 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.

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

2012-13-07 The Boeing Company: Amendment 39-17109; Docket No. FAA-
2012-0673; Directorate Identifier 2012-NM-091-AD.

(a) Effective Date

    This AD is effective July 17, 2012.

(b) Affected ADs

    This AD affects AD 2011-04-10, Amendment 39-16609 (76 FR 9498, 
February 18, 2011).

(c) Applicability

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

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 57, Wings.

(e) Unsafe Condition

    This AD was prompted by reports of corrosion found on carriage 
spindles that are located on the outboard flaps. We are issuing this 
AD to detect and correct corrosion of the carriage spindle, which 
could result in a fracture; fracture of both the inboard and 
outboard carriage spindles, at the forward ends through the large 
diameters, on a single flap, could adversely affect the continued 
safe flight and landing of the airplane.

(f) Compliance

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

(g) Inspection To Determine Suspect Carriage Spindle

    Within 90 days after the effective date of this AD, do an 
inspection of the part or a records review to determine whether a 
suspect carriage with a high velocity oxygenated fuel (HVOF) thermal 
coating is installed at wing butt line (WBL) 254 or WBL 355, in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-57A1319, dated April 16, 2012, as revised by 
Boeing Alert Service Bulletin 737-57A1319, Revision 1, dated June 6, 
2012. If no suspect carriage is installed, no further action is 
required by this paragraph.

(h) Repetitive Inspections, Related Investigative Actions, and 
Corrective Action

    (1) For airplanes on which any suspect carriage is installed, or 
if the part number of the carriage cannot be determined: Within 90 
days after the effective date of this AD, or within 180 days after 
installation of a suspect carriage, whichever occurs later, do a 
detailed or borescope inspection of the forward end of the carriage 
spindle for corrosion and flaking and missing thermal coating, and 
do all applicable related investigative and corrective actions, in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-57A1319, dated April 16, 2012, as revised by 
Boeing Alert Service Bulletin 737-57A1319, Revision 1, dated June 6, 
2012. Do all applicable related investigative and corrective actions 
before further flight. Repeat the detailed or borescope inspection 
thereafter at intervals not to exceed 180 days.
    (2) For the purposes of this AD, a ``serviceable part'' can be 
either a suspect part (i.e., a carriage with HVOF thermal coating) 
or a non-suspect part (i.e., a carriage that does not have HVOF 
thermal coating).

(i) Optional Terminating Action

    Replacement of a suspect carriage with a new or serviceable 
carriage without HVOF thermal coating, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
57A1319, dated April 16, 2012, as revised by Boeing Alert Service 
Bulletin 737-57A1319, Revision 1, dated June 6, 2012, terminates the 
requirements of paragraph (h) of this AD for that carriage spindle 
only.

(j) Parts Installation

    As of the effective date of this AD, a serviceable HVOF-coated 
carriage may not be installed on an airplane unless the actions 
required by paragraph (h)(1) of this AD are done on that carriage 
prior to installation.

(k) Credit for Previous Actions

    This paragraph provides credit for the inspections required by 
paragraphs (g) and (h) of this AD, and the replacement specified in 
paragraph (i) of this AD, if those actions were performed before the 
effective date of this AD using Boeing Alert Service Bulletin 737-
57A1319, dated April 16, 2012.

(l) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
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 emailed 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.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD if it is approved by the 
Boeing Commercial Airplanes Organization Designation Authorization 
(ODA) that has been authorized by the Manager, Seattle ACO to make 
those findings. For a repair method to be approved, the repair must 
meet the certification basis of the airplane, and the approval must 
specifically refer to this AD.
    (4) The inspection required by paragraph (h) of this AD may be 
used as an AMOC for the initial and repetitive detailed or borescope 
inspections required by paragraphs (h) and (i) of AD 2011-04-10, 
Amendment 39-16609 (76 FR 9498, February 18, 2011), provided the 
inspections are accomplished at the compliance times required by 
that AD.

(m) Related Information

    For more information about this AD, contact Nancy Marsh, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, Washington 
98057-3356; phone: (425) 917-6440; fax: (425) 917-6590; email: 
Nancy.Marsh@faa.gov.

(n) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the following service 
information under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use the following service information to do the 
actions required by this AD, unless the AD specifies otherwise.
    (i) Boeing Alert Service Bulletin 737-57A1319, dated April 16, 
2012.
    (ii) Boeing Alert Service Bulletin 737-57A1319, Revision 1, 
dated June 6, 2012.
    (3) 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; telephone 
206-544-5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com.
    (4) You may review copies of the 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.
    (5) You may also review copies of the service information that 
is incorporated by

[[Page 39156]]

reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at an 
NARA facility, 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 June 21, 2012.
John P. Piccola,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-15898 Filed 6-29-12; 8:45 am]
BILLING CODE 4910-13-P


