[Federal Register Volume 78, Number 126 (Monday, July 1, 2013)]
[Proposed Rules]
[Pages 39193-39198]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-15660]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0542; Directorate Identifier 2011-NM-162-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede an existing airworthiness directive 
(AD) that applies to all The Boeing Company Model 737-100, -200, -200C, 
-300, -400, and -500 series airplanes. The existing AD currently 
requires repetitive inspections for discrepancies of each carriage 
spindle of the outboard mid-flaps; repetitive gap checks of the inboard 
and outboard carriages of the outboard mid-flaps to detect fractured 
carriage spindles; measuring to ensure that any new or serviceable 
carriage spindle meets minimum allowable diameter measurements taken at 
three locations; repetitive inspections, measurements, and overhaul of 
the carriage spindles; replacement of any carriage spindle when it has 
reached its maximum life limit; and corrective actions if necessary. 
Since we issued that AD, we received a report of failure of both flap 
carriages. This proposed AD would require reducing the life limit of 
the carriages, reducing the repetitive interval for certain inspections 
and gap checks for certain carriages. This proposed AD would also add 
an option, for certain replacements, of doing an inspection, and 
related investigative and corrective actions if necessary. We are 
proposing this AD to detect and correct cracked, corroded, or fractured 
carriage spindles, which could lead to severe flap asymmetry, and could 
result in reduced control or loss of controllability of the airplane.

DATES: We must receive comments on this proposed AD by August 15, 2013.

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: 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; 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://

[[Page 39194]]

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 (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 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: (425) 917-
6440; fax: (425)917-6590; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2013-0542; 
Directorate Identifier 2011-NM-162-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

    On July 14, 2010, we issued AD 2010-15-08, Amendment 39-16374 (75 
FR 43803, July 27, 2010), for all Model 737-100, -200, -200C, -300, -
400, and -500 series airplanes. That AD requires repetitive inspections 
to find discrepancies (cracks, fractures, and corrosion) of each 
carriage spindle of the left and right outboard mid-flaps; repetitive 
gap checks of the inboard and outboard carriages of the outboard mid-
flaps to detect fractured carriage spindles; measuring to ensure that 
any new or serviceable carriage spindle meets minimum allowable 
diameter measurements taken at three locations; repetitive inspections, 
measurements, and overhaul of the carriages; replacement of any 
carriage when it has reached its maximum life limit; and corrective 
actions if necessary. That AD resulted from reports of fractures that 
resulted from stress corrosion and pitting along the length of the 
carriage spindle and spindle diameter. We issued that AD to detect and 
correct cracked, corroded, or fractured carriage spindles, and to 
prevent severe flap asymmetry, which could result in reduced control or 
loss of controllability of the airplane.

Actions Since Existing AD (75 FR 43803, July 27, 2010) Was Issued

    Since we issued AD 2010-15-08, Amendment 39-16374 (75 FR 43803, 
July 27, 2010), we received a report of failure of both flap carriages 
on an outboard flap of a Model 737 airplane, which indicates that life 
limits and certain repetitive inspection intervals of the carriages 
mandated by existing AD 2010-15-08 should be reduced.

Relevant Service Information

    AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), 
referred to Boeing Alert Service Bulletin 737-57A1277, Revision 1, 
dated November 25, 2003; and Boeing Alert Service Bulletin 737-57A1218, 
Revision 5, dated February 9, 2009; as the appropriate sources of 
service information for the required actions. Boeing has since revised 
these service bulletins.
    We reviewed Boeing Service Bulletin 737-57A1277, Revision 3, dated 
May 16, 2012, which describes reduced repetitive intervals for the non-
destructive test (NDT) ultrasonic inspection and general visual 
inspection of the carriage spindle, and gap check measurements of the 
inboard and outboard carriages.
    The related investigative actions of Boeing Service Bulletin 737-
57A1277, Revision 3, dated May 16, 2012, include removing the carriage 
from service and performing a detailed inspection for corrosion, 
cracking, or a severed spindle; determining if there is damage that 
would cause the midflap to move away from the carriage.
    Corrective actions of Boeing Service Bulletin 737-57A1277, Revision 
3, dated May 16, 2012, include installing a new or serviceable inboard 
or outboard carriage of the outboard mid-flaps.
    We also reviewed Boeing Alert Service Bulletin 737-57A1218, 
Revision 6, dated June 9, 2011, which shortens the life limit and 
compliance time for the replacement of spindles from 48,000 total 
flight cycles to 40,000 total accumulated flight cycles.
    The related investigative actions of Boeing Alert Service Bulletin 
737-57A1218, Revision 6, dated June 9, 2011, include performing a 
detailed inspection for corrosion and pitting, performing a magnetic 
particle inspection for cracking, and measuring for minimum allowable 
spindle diameter. Corrective actions of Boeing Alert Service Bulletin 
737-57A1218, Revision 6, dated June 9, 2011, include installing a new 
or serviceable inboard and outboard carriage of the outboard mid-flaps; 
overhauling carriages to remove corrosion or repair damage; and 
replacing any carriage that has cracking, or damage beyond the repair 
limits for minimum allowable spindle diameters, or reached its life 
limit.

Explanation of Changes to Existing Requirements of AD 2010-15-08, 
Amendment 39-16374 (75 FR 43803, July 27, 2010)

    Paragraphs (i) and (k) of existing AD 2010-15-08, Amendment 39-
16374 (75 FR 43803, July 27, 2010), require installing a new or 
serviceable carriage spindle if certain conditions are found. In this 
proposed AD, when these certain conditions are found, rather than 
installing a new or serviceable carriage spindle, operators now have 
the option to first do a detailed inspection to determine if there is 
corrosion, cracking, or a severed spindle, and do related investigative 
and corrective actions if necessary. Therefore, we revised paragraphs 
(i) and (k) of this proposed AD, to include these optional actions. We 
have also added an exception to paragraph (i) of this proposed AD to 
specify that actions in that paragraph are not necessary for carriage 
spindles on which an ultrasonic inspection of the spindle has been done 
and the spindle has been confirmed not to be severed.
    We have revised paragraph (m) of this AD to remove the reference to 
Chapter 20-42-09, Electrodeposited Nickel Plating, of the Boeing (737) 
Standard Overhaul Practices Manual, and we removed the reference that 
as of August 31, 2010, the effective date of AD 2010-15-08, Amendment 
39, 16374 (75 FR 438003) to use only Boeing (737) Standard Overhaul 
Practices Manual, Revision 25, dated July 1, 2009.
    Instead, application of nickel plating done in accordance with a 
method approved by the Manager, Seattle Aircraft Certification Office 
(ACO), FAA, is acceptable for compliance with the actions required by 
paragraph (m) of this AD. We added Note 1 to paragraph (m) of this AD 
to specify that guidance on the application of nickel plating can be 
found in Chapter 20-42-09, Electrodeposited Nickel Plating, of the 
Boeing (737) Standard Overhaul Practices Manual, Revision 25, dated 
July 1, 2009.

[[Page 39195]]

    We have also added paragraph (m)(3) to prohibit the application of 
any plating to the carriage using any high velocity oxygen fuel (HVOF) 
thermal spray process.
    We have also clarified the compliance time for the repetitive 
actions specified in paragraph (n) of AD 2010-15-08, Amendment 39-16374 
(75 FR 43803, July 27, 2010).

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 these same type 
designs.

Proposed AD Requirements

    This proposed AD would retain all requirements of AD 2010-15-08, 
Amendment 39-16374 (75 FR 43803, July 27, 2010). This proposed AD also 
would require accomplishing the actions specified in the service 
information described previously. This proposed AD would also shorten 
certain compliance times.

Costs of Compliance

    We estimate that this proposed AD affects 652 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Action                       Labor cost         Parts cost     Cost per product                     Cost on U.S. operators
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspections [retained actions from    12 work-hours x $85              $0  $1,020 per inspection   $665,040 per inspection cycle.
 existing AD 2010[dash]15[dash]08,     per hour = $1,020.                   cycle.
 Amendment 39[dash]16374 (75 FR
 43803, July 27, 2010)].
Inspections and measurements          2 work-hours x $85 per            0  $170 per inspection     $110,840 per inspection and measurement cycle
 [retained actions from existing AD    hour = $170.                         and measurement
 2010[dash]15[dash]08, Amendment                                            cycle..
 39[dash]16374 (75 FR 43803, July
 27, 2010)].
Overhauls [retained actions from      16 work-hours x $85       \1\28,000  $29,360 per overhaul    $19,142,720 per overhaul cycle.
 existing AD 2010[dash]15[dash]08,     per hour = $1,360.                   cycle.
 Amendment 39[dash]16374 (75 FR
 43803, July 27, 2010)].
Replacements [retained actions from   16 work-hours x $85       \2\60,000  $61,360 per             $40,006,720 per replacement cycle.
 existing AD 2010[dash]15[dash]08,     per hour = $1,360.                   replacement cycle.
 Amendment 39[dash]16374 (75 FR
 43803, July 27, 2010)].
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ $7,000 per spindle; 4 spindles per airplane.
\2\ $15,000 per spindle; 4 spindles per airplane.

    The new requirements of this proposed AD add no additional economic 
burden.

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 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 that the 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

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 removing airworthiness directive (AD) 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), and adding 
the following new AD:

The Boeing Company: Docket No. FAA-2013-0542; Directorate Identifier 
2011-NM-162-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by August 15, 
2013.

(b) Affected ADs

    This AD supersedes AD 2010-15-08, Amendment 39-16374 (75 FR 
43803, July 27, 2010).

(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.

[[Page 39196]]

(e) Unsafe Condition

    This AD was prompted by reports of fractures that resulted from 
stress corrosion and pitting along the length of the spindle and 
spindle diameter, and a subsequent report of failure of both flap 
carriages. We are issuing this AD to detect and correct cracked, 
corroded, or fractured carriage spindles, which could lead to severe 
flap asymmetry, and could result in reduced control or loss of 
controllability of the airplane.

(f) Compliance

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

(g) Compliance Times for Paragraphs (h) and (j) of This AD

    This paragraph restates the requirements of paragraph (g) of AD 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with 
revised service information that shortens the compliance times for 
certain inspections. The tables in paragraph 1.E., ``Compliance,'' 
of Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated 
November 25, 2003; and Boeing Service Bulletin 737-57A1277, Revision 
3, dated May 16, 2012; specify the compliance times for paragraphs 
(g) through (k) of this AD. For carriage spindles that have 
accumulated the number of flight cycles or years in service 
specified in the ``Threshold'' column of the tables in paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 737-57A1277, 
Revision 1, dated November 25, 2003, accomplish the gap check, 
nondestructive test (NDT) inspection, and general visual inspection 
specified in paragraphs (h) and (j) of this AD within the 
corresponding interval after December 4, 2003 (the effective date AD 
2003-24-08, Amendment 39-16337 (68 FR 67027, December 1, 2003)), as 
specified in the ``Interval'' column of the tables in paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 737-57A1277, 
Revision 1, dated November 25, 2003, except as specified in 
paragraphs (g)(1) and (g)(2) of this AD. Repeat the gap check, NDT, 
and general visual inspections at the intervals specified in the 
``Interval'' column of the tables in paragraph 1.E., ``Compliance,'' 
of Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated 
November 25, 2003, except as specified in paragraph (g)(1) and 
(g)(2) of this AD. As of the effective date of this AD, accomplish 
the gap check, NDT inspection, and general visual inspections 
specified in paragraphs (h) and (j) of this AD within the 
corresponding interval as specified in the ``Interval'' column of 
the tables in paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003, 
and thereafter at the intervals specified in Boeing Service Bulletin 
737-57A1277, Revision 3, dated May 16, 2012, except as specified in 
paragraphs (g)(1) and (g)(2) of this AD. Repeat the gap check, NDT, 
and general visual inspections thereafter at the intervals specified 
in the ``Interval'' column of the tables in paragraph 1.E., 
``Compliance,'' of Boeing Service Bulletin 737-57A1277, Revision 3, 
dated May 16, 2012, except as specified in paragraphs (g)(1) and 
(g)(2) of this AD.
    (1) The gap check does not have to be done at the same time as 
an NDT inspection; after doing an NDT inspection, the interval for 
doing the next gap check may be measured from the NDT inspection.
    (2) As carriage spindles gain flight cycles or years in service 
and move from one category in the ``Threshold'' column to another, 
they are subject to the repetitive inspection intervals 
corresponding to the new threshold category.

(h) Retained Work Package 2: Gap Check

    This paragraph restates the requirements of paragraph (h) of AD 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with 
revised service information. Perform a gap check of the inboard and 
outboard carriage of the left and right outboard mid-flaps to 
determine if there is a positive indication of a severed carriage 
spindle, in accordance with Work Package 2 of paragraph 3.B., ``Work 
Instructions,'' of Boeing Alert Service Bulletin 737-57A1277, 
Revision 1, dated November 25, 2003; or Boeing Service Bulletin 737-
57A1277, Revision 3, dated May 16, 2012. As of the effective date of 
this AD, only Boeing Service Bulletin 737-57A1277, Revision 3, dated 
May 16, 2012, may be used to perform the actions specified in this 
paragraph.

(i) Retained Work Package 2: Corrective Actions With New Optional 
Actions and Exception

    This paragraph restates the requirements of paragraph (i) of AD 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with 
revised service information and new optional actions and exception. 
If there is a positive indication of a severed carriage spindle 
during the gap check required by paragraph (h) of this AD, before 
further flight, do the actions specified in paragraph (i)(1) or 
(i)(2) of this AD, except for carriage spindles on which an 
ultrasonic inspection has been done in accordance with the ``Work 
Instructions'' of Boeing Service Bulletin 737-57A1277, Revision 3, 
dated May 16, 2012; and the spindle has been confirmed not to be 
severed, no further actions are required by this paragraph for that 
carriage spindle.
    (1) Remove the carriage spindle and install a new or serviceable 
carriage spindle, in accordance with the ``Work Instructions'' of 
any service bulletin specified in paragraph (i)(1)(i), (i)(1)(ii), 
(i)(1)(iii), or (i)(1)(iv) of this AD. As of the effective date of 
this AD, only Boeing Service Bulletin 737-57A1277, Revision 3, dated 
May 16, 2012, may be used to perform the actions specified in this 
paragraph.
    (i) Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated 
November 25, 2003.
    (ii) Boeing Service Bulletin 737-57A1277, Revision 3, dated May 
16, 2012.
    (iii) Boeing Alert Service Bulletin 737-57A1218, Revision 5, 
dated February 9, 2009.
    (iv) Boeing Alert Service Bulletin 737-57A1218, Revision 6, 
dated June 9, 2011
    (2) Do a detailed inspection of the spindle to determine if 
there is corrosion, cracking, or a severed spindle, and, before 
further flight, do all related investigative and corrective actions, 
in accordance with the ``Work Instructions'' of Boeing Alert Service 
Bulletin 737-57A1277, Revision 1, dated November 25, 2003; or Boeing 
Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012. If, 
during the detailed inspection described in paragraph 4.b. of Work 
Package 2 of Boeing Alert Service Bulletin 737-57A1277, Revision 1, 
dated November 25, 2003, or Revision 3, dated May 16, 2012, a 
carriage spindle is found not to be severed, and no corrosion and no 
cracking is present, it can be reinstalled on the outboard mid-flap, 
in accordance with any service bulletin specified in paragraph 
(i)(2)(i), (i)(2)(ii), (i)(2)(iii), or (i)(2)(iv) of this AD. As of 
the effective date of this AD, only Boeing Service Bulletin 737-
57A1277, Revision 3, dated May 16, 2012, may be used to perform the 
actions specified in this paragraph.
    (i) Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated 
November 25, 2003.
    (ii) Boeing Service Bulletin 737-57A1277, Revision 3, dated May 
16, 2012.
    (iii) Boeing Alert Service Bulletin 737-57A1218, Revision 5, 
dated February 9, 2009.
    (iv) Boeing Alert Service Bulletin 737-57A1218, Revision 6, 
dated June 9, 2011

(j) Retained Work Package 1: NDT (Ultrasonic) and General Visual 
Inspections

    This paragraph restates the requirements of paragraph (j) of AD 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with 
revised service information. Perform an NDT (ultrasonic) inspection 
and general visual inspection for each carriage spindle of the left 
and right outboard mid-flaps to detect cracks, corrosion, or severed 
carriage spindles, in accordance with ``Work Package 1'' of the 
``Work Instructions'' of Boeing Alert Service Bulletin 737-57A1277, 
Revision 1, dated November 25, 2003; or Boeing Service Bulletin 737-
57A1277, Revision 3, dated May 16, 2012. As of the effective date of 
this AD, only Boeing Service Bulletin 737-57A1277, Revision 3, dated 
May 16, 2012, may be used to perform the actions specified in this 
paragraph.

(k) Retained Work Package 1: Corrective Actions and New Optional Action

    This paragraph restates the requirements of paragraph (k) of AD 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with 
revised service information and new optional action. If any 
corroded, cracked, or severed carriage spindle is found during any 
inspection required by paragraph (j) of this AD: Before further 
flight, do the actions specified in paragraph (k)(1) or (k)(2) of 
this AD.
    (1) Remove the carriage spindle and install a new or serviceable 
carriage spindle, in accordance any service bulletin identified in 
paragraph (k)(1)(i), (k)(1)(ii), (k)(1)(iii), or (k)(1)(iv) of this 
AD. As of the effective date of this AD, only Boeing Service 
Bulletin 737-57A1277, Revision 3, dated May 16, 2012, may be used to 
perform the actions specified in this paragraph.
    (i) Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated 
November 25, 2003.
    (ii) Boeing Service Bulletin 737-57A1277, Revision 3, dated May 
16, 2012.

[[Page 39197]]

    (iii) Boeing Alert Service Bulletin 737-57A1218, Revision 5, 
dated February 9, 2009.
    (iv) Boeing Alert Service Bulletin 737-57A1218, Revision 6, 
dated June 9, 2011
    (2) Do a detailed inspection of the spindle to determine if 
there is corrosion, cracking, or a severed spindle, in accordance 
with the ``Work Instructions'' of Boeing Alert Service Bulletin 737-
57A1277, Revision 1, dated November 25, 2003; or Boeing Service 
Bulletin 737-57A1277, Revision 3, dated May 16, 2012. If any 
corrosion, cracking, or a severed spindle is found, before further 
flight, install a new or serviceable carriage spindle, in accordance 
any service bulletin identified in paragraph (k)(1)(i), (k)(1)(ii), 
(k)(1)(iii), or (k)(1)(iv) of this AD. As of the effective date of 
this AD, only Boeing Service Bulletin 737-57A1277, Revision 3, dated 
May 16, 2012, may be used to perform the actions specified in this 
paragraph.

(l) Retained Parts Installation Limitation

    This paragraph restates the requirements of paragraph (l) of AD 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010). Except 
as provided in paragraph (i) of this AD: As of December 4, 2003 (the 
effective date AD 2003-24-08, Amendment 39-16337 (68 FR 67027, 
December 1, 2003), no person may install on any airplane a carriage 
spindle that has been removed as required by paragraph (i) or (k) of 
this AD, unless it has been overhauled in accordance with the ``Work 
Instructions'' of the applicable service bulletin identified in 
paragraph (l)(1), (l)(2), (l)(3), or (l)(4) of this AD. As of the 
effective date of this AD, only Boeing Service Bulletin 737-57A1277, 
Revision 3, dated May 16, 2012; or Boeing Alert Service Bulletin 
737-57A1218, Revision 6, dated June 9, 2011; may be used to perform 
the actions specified in this paragraph. To be eligible for 
installation under this paragraph, the carriage spindle must have 
been overhauled in accordance with the requirements of paragraph (m) 
of this AD.
    (1) Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated 
November 25, 2003.
    (2) Boeing Service Bulletin 737-57A1277, Revision 3, dated May 
16, 2012.
    (3) Boeing Alert Service Bulletin 737-57A1218, Revision 5, dated 
February 9, 2009.
    (4) Boeing Alert Service Bulletin 737-57A1218, Revision 6, dated 
June 9, 2011.

(m) Retained Electrodeposited Nickel Plating With New Plating 
Restrictions

    This paragraph restates the requirements of paragraph (m) of AD 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010) with 
revised plating application procedures. As of the effective date of 
this AD, during accomplishment of any overhaul specified in 
paragraph (l) or (o) of this AD, follow the requirements specified 
in paragraphs (m)(1), (m)(2), and (m)(3) of this AD during 
application of the plating to the carriage spindle, in accordance 
with a method approved by the Manager, Seattle, Aircraft 
Certification Office (ACO), FAA. 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.
    (1) The maximum deposition rate of the nickel plating in any one 
plating/baking cycle must not exceed 0.002-inch-per-hour.
    (2) Begin the hydrogen embrittlement relief bake within 10 hours 
after application of the nickel plating, or less than 24 hours after 
the current was first applied to the part, whichever is first.
    (3) The carriage must not be plated using any high velocity 
oxygen fuel (HVOF) thermal spray process.

    Note 1 to paragraph (m) of this AD: Guidance on the application 
of nickel plating can be found in Chapter 20-42-09, Electrodeposited 
Nickel Plating, of the Boeing (737) Standard Overhaul Practices 
Manual, Revision 25, dated July 1, 2009.

(n) Retained Exception to Reporting Recommendations

    This paragraph restates the provisions of paragraph (n) of AD 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with 
revised service information. Although Boeing Alert Service Bulletin 
737-57A1277, Revision 1, dated November 25, 2003; and Boeing Service 
Bulletin 737-57A1277, Revision 3, dated May 16, 2012; recommend that 
operators report inspection findings to the manufacturer, this AD 
does not require reporting.

(o) Retained Inspections, Measurements, and Overhauls of the Carriage 
Spindle With Clarification of Overhaul Restrictions

    This paragraph restates the requirements of paragraph (o) of AD 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010) with 
clarification of overhaul restrictions. At the applicable times 
specified in paragraphs (o)(1) and (o)(2) of this AD: Do the 
detailed inspection for corrosion, pitting, and cracking of the 
carriage spindle; magnetic particle inspection for cracking of the 
carriage spindle; measurements of the spindle to determine if it 
meets the allowable minimum diameter; overhauls of the carriage 
spindle; and applicable corrective actions; in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
57A1218, Revision 5, dated February 9, 2009; or Boeing Alert Service 
Bulletin 737-57A1218, Revision 6, dated June 9, 2011. As of the 
effective date of this AD, only Boeing Alert Service Bulletin 737-
57A1218, Revision 6, dated June 9, 2011, may be used to perform the 
actions specified in this paragraph. The applicable corrective 
actions must be done before further flight. Repeat these actions 
thereafter at intervals not to exceed every 12,000 flight cycles on 
the carriage spindle or every 8 years since first installation of 
the carriage spindle on the airplane, whichever comes first. As of 
the effective date of this AD: For any overhaul required by this 
paragraph, the carriage spindle must be overhauled in accordance 
with the requirements of paragraph (m) of this AD.
    (1) For Model 737-100, -200, -200C series airplanes: At the 
later of the times specified in paragraphs (o)(1)(i) and (o)(1)(ii) 
of this AD.
    (i) Before the accumulation of 12,000 total flight cycles on the 
carriage spindle since new or overhauled, or within 8 years after 
the installation of the new or overhauled part, whichever comes 
first.
    (ii) Within 1 year after August 31, 2010 (the effective date of 
AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010)).
    (2) For Model -300, -400, and -500 series airplanes: At the 
later of the times specified in paragraphs (o)(2)(i) and (o)(2)(ii) 
of this AD.
    (i) Before the accumulation of 12,000 total flight cycles on the 
carriage spindle since new or overhauled, or within 8 years after 
the installation of the new or overhauled part, whichever comes 
first.
    (ii) Within 2 years after August 31, 2010 (the effective date of 
AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010)).

(p) Retained Carriage Spindle Replacement for Model 737-100, -200, and 
-200C Series Airplanes

    This paragraph restates the requirements of paragraph (p) of AD 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with 
revised service information and a shortened compliance time. For 
Model 737-100, -200, -200C series airplanes: Replace the carriage 
spindle with a new or documented (for which the service life, in 
total flight cycles, is known) carriage spindle, in accordance with 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-57A1218, Revision 5, dated February 9, 2009; or Boeing Alert 
Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011; at the 
earlier of the times specified in paragraphs (p)(1) and (p)(2) of 
this AD, except as required by paragraph (r) of this AD. As of the 
effective date of this AD, only Boeing Alert Service Bulletin 737-
57A1218, Revision 6, dated June 9, 2011, may be used to perform the 
replacement. Overhauling the carriage spindles does not zero-out the 
flight cycles. Total flight cycles accumulate since new.
    (1) At the later of the times specified in paragraphs (p)(1)(i) 
and (p)(1)(ii) of this AD.
    (i) Before the accumulation of 48,000 total flight cycles on the 
new or overhauled carriage.
    (ii) Within 3 years or 7,500 flight cycles after August 31, 2010 
(the effective date of AD 2010-15-08, Amendment 39-16374 (75 FR 
43803, July 27, 2010)), whichever occurs first.
    (2) Before the accumulation of 40,000 total flight cycles on the 
new or overhauled carriage or 6 months after the effective date of 
this AD, whichever occurs later.

(q) Retained Carriage Spindle Replacement for Model 737-300, -400, and 
-500 Series Airplanes

    This paragraph restates the requirements of paragraph (q) of AD 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with 
revised service information and a shortened compliance time. For 
Model 737-300, -400, and -500 series airplanes: Replace the carriage 
spindle with a new or documented (for which the service life, in 
flight cycles, is known) carriage spindle, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin

[[Page 39198]]

737-57A1218, Revision 5, dated February 9, 2009; or Boeing Alert 
Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011; at the 
later of the times specified in paragraphs (q)(1) and (q)(2) of this 
AD, except as required by paragraph (r) of this AD. As of the 
effective date of this AD, only Boeing Alert Service Bulletin 737-
57A1218, Revision 6, dated June 9, 2011, may be used to perform the 
replacement required by this paragraph. Overhauling the carriage 
spindles does not zero-out the flight cycles. Total flight cycles 
accumulate since new.
    (1) Before the accumulation of 40,000 total flight cycles on the 
new or overhauled carriage.
    (2) Within 6 years or 15,000 flight cycles after August 31, 2010 
(the effective date of AD 2010-15-08, Amendment 39-16374 (75 FR 
43803, July 27, 2010)), whichever occurs first.

(r) Retained Carriage Spindle Replacement for Airplanes With an 
Undocumented Carriage

    This paragraph restates the requirements of paragraph (r) of AD 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010). For 
airplanes with an undocumented carriage: Do the applicable actions 
specified in paragraph (p) or (q) of this AD at the applicable time 
specified in paragraph (r)(1) or (r)(2) of this AD.
    (1) For Model 737-100, -200, -200C series airplanes: Do the 
actions specified in paragraph (p) of this AD at the time specified 
in paragraph (p)(1)(ii) of this AD.
    (2) For Model -300, -400, and -500 series airplanes: Do the 
actions specified in paragraph (q) of this AD at the time specified 
in paragraph (q)(2) of this AD.

(s) Retained Repetitive Replacements of Carriage Spindle

    This paragraph restates the requirements of paragraph (s) of AD 
2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with 
revised compliance times.
    (1) For airplanes on which the actions required by paragraph (p) 
or (q) of this AD, as applicable, have been done as of the effective 
date of this AD: Repeat the replacement of the carriage spindle 
specified by paragraph (p) or (q) of this AD, as applicable, one 
time at the later of the times specified in paragraphs (s)(1)(i) and 
(s)(1)(ii) of this AD, and thereafter at intervals not to exceed 
40,000 total flight cycles on the new or overhauled carriage 
spindle.
    (i) Before the accumulation of 40,000 total flight cycles on the 
new or overhauled carriage.
    (ii) Within 6 years or 15,000 flight cycles after August 31, 
2010 (the effective date of AD 2010-15-08, Amendment 39-16374 (75 FR 
43803, July 27, 2010)), whichever occurs first.
    (2) For airplanes on which the actions required by paragraph (p) 
or (q) of this AD, as applicable, have not been done as of the 
effective date of this AD: Repeat the replacement of the carriage 
spindle specified by paragraph (p) or (q) of this AD, as applicable, 
thereafter at intervals not to exceed 40,000 total flight cycles on 
the new or overhauled carriage spindle.

(t) Exception to Compliance Time

    Where Boeing Service Bulletin 737-57A1277, Revision 3, dated May 
16, 2012, and Boeing Alert Service Bulletin 737-57A1218, Revision 6, 
dated June 9, 2011, specify a compliance time after the dates of 
those service bulletins, this AD requires compliance within the 
specified compliance time after the effective date of this AD.

(u) Credit for Previous Actions

    This paragraph provides credit for actions required by 
paragraphs (g) through (s) of this AD, if those actions were 
performed before the effective date of this AD using Boeing Alert 
Service Bulletin 737-57A1277, Revision 2, dated June 9, 2011, which 
is not incorporated by reference in this AD.

(v) 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: [email protected].
    (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, 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) AMOCs previously approved in accordance with AD 2003-24-08, 
Amendment 39-13377 (68 FR 67027, December 1, 2003), or AD 2010-15-
08, Amendment 39-16374 (75 FR 43803, July 27, 2010), are approved as 
AMOCs for individual repairs are acceptable for compliance with the 
corresponding provisions of this AD. All other existing AMOCs are 
not acceptable.

(w) Related Information

    (1) For more information about this AD, contact Nancy Marsh, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057-
3356; phone: (425) 917-6440; fax: (425) 917-6590; email: 
[email protected].
    (2) 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; email 
[email protected]; 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.

    Issued in Renton, Washington, on June 14, 2013.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-15660 Filed 6-28-13; 8:45 am]
BILLING CODE 4910-13-P