
[Federal Register Volume 77, Number 59 (Tuesday, March 27, 2012)]
[Proposed Rules]
[Pages 18137-18140]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-7283]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0299; Directorate Identifier 2011-NM-029-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 adopt a new airworthiness directive (AD) for all 
Boeing Model 747-100, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 
747-400F, and 747SR series airplanes. This proposed AD was prompted by 
reports of broken and damaged latch pin retention bolts of the main 
deck side cargo door (MDSCD), latch pin migration, and broken latch pin 
fittings. This proposed AD would require various repetitive inspections 
of the MDSCD latch pin fittings, measuring the latch pin, and related 
investigative and corrective actions if necessary; and modifying the 
latch pin fittings and installing new latch pins and latch pin 
fasteners. We are proposing this AD to prevent loss of the cargo door 
and rapid depressurization of the airplane.

DATES: We must receive comments on this proposed AD by May 11, 2012.

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.

[[Page 18138]]

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

FOR FURTHER INFORMATION CONTACT: Bill Ashforth, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: 425-
917-6432; fax: 425-917-6590; email: Bill.Ashforth@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-2012-0299; 
Directorate Identifier 2011-NM-029-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 damage reports on MDSCD latch pin fittings. Six 
operators have reported that broken latch pin retention bolts were 
found on eight airplanes. On one airplane that had accumulated 101,609 
total flight hours and 12,862 total flight cycles, the retention bolts 
on both the 9 and 10 latch pin fittings were broken. 
Latch pin 10 had migrated aft and was not engaging the latch 
cam. On another airplane that had accumulated 33,983 total flight hours 
and 4,723 total flight cycles, the retention bolt on the 10 
latch pin fitting was broken and the 9 latch pin was damaged. 
On another airplane that had accumulated 67,188 total flight hours and 
14,440 total flight cycles, the retention bolt for the 10 
latch pin fitting was completely sheared, which allowed the latch pin 
to migrate aft until it no longer engaged the door latch cam. On four 
airplanes, only the retention bolt on the 10 latch pin fitting 
was found to be broken. On one airplane, the retention bolt on the 
10 latch pin fitting was damaged. A loose, broken, or missing 
retention bolt can result in a migrated latch pin, which can become 
disengaged from the cargo door latch cams and lead to increased loads 
in the adjacent latch pin fittings and latch cams. Increased loads can 
cause damage to the cargo door latch mechanism and/or the lower sill 
structure. The migration of two or more latch pins and subsequent 
failure of the latch mechanism or lower sill structure can result in 
the inability of the cargo door to carry limit loads. This condition, 
if not corrected, could result in the loss of the cargo door and rapid 
depressurization of the airplane.

Relevant Service Information

    We reviewed Boeing Alert Service Bulletin 747-52A2294, Revision 1, 
dated August 16, 2011, as revised by Boeing Alert Service Bulletin 747-
52A2294, Revision 2, dated December 12, 2011. For information on the 
procedures and compliance times, see this service information at http://www.regulations.gov by searching for Docket No. FAA-2012-0299.

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 repetitive detailed inspections of 
the 10 MDSCD latch pin fittings to detect loose, broken, missing, or 
damaged retention bolts and nuts; measuring latch pin diameter; and 
related investigative and corrective actions, if necessary. The related 
investigative actions include a torque check of the latch pin retention 
bolt to determine if the bolt is broken; and checking the latch pin for 
migration and, if necessary, a detailed inspection for damage of the 
latch pin fitting and the adjacent (forward and aft) latch pin 
fittings, the door cutout structure, the affected latch cam and the 
adjacent latch cams, and the door structure. The corrective actions 
include replacing the latch pin, the retention bolt, and related parts 
with a new latch pin, retention bolt, and related parts; and repairing 
of any damage to the adjacent door, door cutout structure, and latch 
cams.
    This proposed AD would also require modifying the MDSCD latch pin 
fittings, replacing the latch pins with new latch pins, and replacing 
the latch pin retention fasteners with new latch pin retention 
fasteners. In addition, this proposed AD would require post-
modification/replacement repetitive detailed inspections of the MDSCD 
latch pin fittings to detect damaged latch pins, and loose, broken, or 
missing retention bolts and nuts; measuring the latch pin diameter; and 
related investigative and corrective actions if necessary. The related 
investigative actions include checking the latch pin for migration and, 
if necessary, a detailed inspection for damage of the latch pin fitting 
and the adjacent latch pin fittings, the door cutout structure, the 
affected latch cam and the adjacent latch cams on the door, and the 
door structure. The corrective actions include replacing the latch pin, 
the retention bolt, and related parts with a new latch pin, retention 
bolt, and related parts; or repairing any damage.

Differences Between the Proposed AD and the Service Information

    Boeing Alert Service Bulletin 747-52A2294, Revision 1, dated August 
16, 2011. as revised by Boeing Alert Service Bulletin 747-52A2294, 
Revision 2, dated December 12, 2011, specifies to contact the 
manufacturer for instructions on how to repair certain conditions, but 
this proposed AD would require repairing those conditions in one of the 
following ways:
     In accordance with a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by the Boeing Commercial 
Airplanes Organization Designation Authorization (ODA) whom we have 
authorized to make those findings.

[[Page 18139]]

Costs of Compliance

    We estimate that this proposed AD will affect 77 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
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                                                                                                 Cost on U.S.
              Action                    Labor cost        Parts cost     Cost per  product        operators
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Detailed inspection, including     4 work-hours x $85               $0  $340 per inspection  $26,180 per
 torque check.                      per hour = $340                      cycle.               inspection cycle.
                                    per inspection
                                    cycle.
Modification.....................  11 work-hours x $85          $5,530  $6,465.............  $497,805.
                                    per hour = $935.
Post-modification detailed         2 work-hours x $85               $0  $170 per inspection  $13,090 per
 inspection.                        per hour = $170                      cycle.               inspection cycle.
                                    per inspection
                                    cycle.
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     We estimate the following costs to do necessary repairs and 
replacements that would be required based on the results of the 
proposed inspection. We have no way of determining the number of 
aircraft that might need these repairs.

                                               On-Condition Costs
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                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Repair/Replacements (Groups 1 and 2 airplanes)  7 work-hours x $85 per hour =            $11,478         $12,073
                                                 $595.
Repair/Replacements (Group 3 airplanes).......  7 work-hours x $85 per hour =             12,254          12,849
                                                 $595.
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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

    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-2012-0299; Directorate Identifier 
2011-NM-029-AD.

(a) Comments Due Date

    We must receive comments by May 11, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 747-100, 747-200B, 
747-200C, 747-200F, 747-300, 747-400, 747-400F, and 747SR series 
airplanes; certificated in any category; as identified in Boeing 
Alert Service Bulletin 747-52A2294, Revision 1, dated August 16, 
2011.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 52, Doors.

(e) Unsafe Condition

    This AD was prompted by reports of broken and damaged latch pin 
retention bolts of the main deck side cargo door (MDSCD), latch pin 
migration, and broken latch pin fittings. We are issuing this AD to 
prevent loss of the cargo door and rapid depressurization of the 
airplane.

(f) Compliance

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

(g) Inspection and Corrective Action

    At the applicable compliance time specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 747-52A2294, 
Revision 1, dated August 16, 2011, as revised by Boeing Alert 
Service Bulletin 747-52A2294, Revision 2, dated December

[[Page 18140]]

12, 2011, except as provided by paragraph (j)(2) of this AD: Do a 
detailed inspection of the 10 MDSCD latch pin fittings to detect 
loose, broken, damaged, or missing retention bolts and nuts; measure 
the latch pin diameter; and do all applicable related investigative 
and corrective actions, except as required by paragraph (j)(1) of 
this AD; in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-52A2294, Revision 1, dated August 
16, 2011, as revised by Boeing Alert Service Bulletin 747-52A2294, 
Revision 2, dated December 12, 2011. Do all applicable related 
investigative and corrective actions before further flight. Repeat 
the inspection thereafter at intervals not to exceed those specified 
in paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
747-52A2294, Revision 1, dated August 16, 2011, as revised by Boeing 
Alert Service Bulletin 747-52A2294, Revision 2, dated December 12, 
2011.

(h) Modification of Latch Pin Fittings and Replacement of Latch Pins 
and Latch Pin Retention Fasteners

    At the time specified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 747-52A2294, Revision 1, dated August 
16, 2011, as revised by Boeing Alert Service Bulletin 747-52A2294, 
Revision 2, dated December 12, 2011, except as provided by paragraph 
(j)(2) of this AD: Modify the 10 MDSCD latch pin fittings, replace 
the latch pins with new latch pins, and replace the latch pin 
retention fasteners with new latch pin retention fasteners, except 
as required by paragraph (j)(1) of this AD, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
52A2294, Revision 1, dated August 16, 2011, as revised by Boeing 
Alert Service Bulletin 747-52A2294, Revision 2, dated December 12, 
2011. Accomplishment of the actions in paragraph (h) of this AD 
terminates the inspection required in paragraph (g) of this AD.

(i) Post-Modification Inspection and Corrective Action

    At the applicable compliance time specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 747-52A2294, 
Revision 1, dated August 16, 2011, as revised by Boeing Alert 
Service Bulletin 747-52A2294, Revision 2, dated December 12, 2011, 
except as provided by paragraph (j)(2) of this AD: Do a detailed 
inspection of the 10 MDSCD latch pin fittings to detect loose, 
broken, damaged, or missing retention bolts and nuts; measure the 
latch pin diameter; and do all applicable related investigative and 
corrective actions, except as required by paragraph (j)(1) of this 
AD; in accordance with the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-52A2294, Revision 1, dated August 16, 
2011, as revised by Boeing Alert Service Bulletin 747-52A2294, 
Revision 2, dated December 12, 2011. Do the applicable related 
investigative and corrective actions before further flight. Repeat 
the inspection thereafter at intervals not to exceed those specified 
in paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
747-52A2294, Revision 1, dated August 16, 2011, as revised by Boeing 
Alert Service Bulletin 747-52A2294, Revision 2, dated December 12, 
2011.

(j) Exceptions to Service Bulletin Specifications

    (1) If any damage is found during any inspection required by 
this AD, and Boeing Alert Service Bulletin 747-52A2294, Revision 1, 
dated August 16, 2011, as revised by Boeing Alert Service Bulletin 
747-52A2294, Revision 2, dated December 12, 2011, specifies to 
contact Boeing for appropriate action: Before further flight, repair 
using a method approved in accordance with the procedures specified 
in paragraph (l) of this AD.
    (2) Where Boeing Alert Service Bulletin 747-52A2294, Revision 1, 
dated August 16, 2011, as revised by Boeing Alert Service Bulletin 
747-52A2294, Revision 2, dated December 12, 2011, specifies a 
compliance time relative to the issue date of that service bulletin, 
this AD requires compliance within the specified compliance time 
after the effective date of this AD.

(k) Credit for Previous Actions

    This paragraph provides credit for actions required by 
paragraphs (g) and (h) of this AD, if those actions were performed 
before the effective date of this AD using Boeing Alert Service 
Bulletin 747-52A2294, dated July 8, 2010.

(l) Alternative Methods of Compliance (AMOCs)

    (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 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 14 CFR 25.571, 
Amendment 45, and the approval must specifically refer to this AD.

(m) Related Information

    (1) For more information about this AD, contact Bill Ashforth, 
Aerospace Engineer, Airframe Branch, ANM-120S, Seattle Aircraft 
Certification Office (ACO), FAA, 1601 Lind Avenue SW., Renton, 
Washington 98057-3356; phone: 425-917-6432; fax: 425-917-6590; 
email: Bill.Ashforth@faa.gov.
    (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; phone: 206-
544-5000, extension 1; fax: 206-766-5680; email: 
me.boecom@boeing.com; Internet: https://www.myboeingfleet.com. You 
may also review the referenced service information in the docket at 
www.regulations.gov (refer to Docket No. FAA-2012-0299). 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 19, 2012.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-7283 Filed 3-26-12; 8:45 am]
BILLING CODE 4910-13-P


