
[Federal Register Volume 77, Number 113 (Tuesday, June 12, 2012)]
[Proposed Rules]
[Pages 34881-34883]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-14253]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0498; Directorate Identifier 2011-NM-212-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 
certain The Boeing Company Model 747-400, -400D, and -400F series 
airplanes. This proposed AD was prompted by reports of crown frame web 
cracking at left buttock line (LBL) 15.0, station (STA) 320. This 
proposed AD would require a measurement of the web at STA 320 and, 
depending on findings, various inspections for cracks and missing 
fasteners, web and fastener replacement, and related investigative and 
corrective actions. We are proposing this AD to prevent complete 
fracture of the crown frame assembly, and consequent damage to the skin 
and in-flight decompression of the airplane.

DATES: We must receive comments on this proposed AD by July 27, 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: 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; 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-2012-0498; 
Directorate Identifier 2011-NM-212-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 five reports of crown frame web cracking at left 
buttock line (LBL) 15.0, station (STA) 320. One airplane crack length 
was not specified and reported at 9,456 flight cycles. Three cracks of 
0.65 inch in length were reported after 9,354 flight cycles on one 
airplane, 12,851 flight cycles on the second airplane, and 29,866 
flight cycles on the third airplane. A crack of 0.85 inch was reported 
at 29,956 flight cycles on another airplane.
    Investigation revealed that in these airplanes, the web was made 
from 0.08-inch thick material and did not conform to production 
drawings. Also, an operator reported missing fasteners from locations 
common to the frame web and lower chord on the first delivered Model 
747-400 after 10,317 flight cycles. This airplane also had a web made 
from 0.08-inch thick material and did not conform to production 
drawings.
    This condition, if not corrected, could result in complete fracture 
of the crown frame assembly, and consequent damage to the skin and in-
flight decompression of the airplane.

Relevant Service Information

    We reviewed Boeing Service Bulletin 747-53A2784, Revision 1, dated 
September 14, 2011. For information on the procedures and compliance 
times, see this service information at http://

[[Page 34882]]

www.regulations.gov by searching for Docket No. FAA No. FAA-2012-0498.

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 identified previously, except as discussed 
under ``Differences Between the Proposed AD and the Service 
Information.'' This proposed AD also provides options for accomplishing 
the actions that are required for airplanes on which no cracking is 
found in the crown frame web.
    The phrase ``related investigative actions'' is used in this 
proposed AD. ``Related investigative actions'' are those actions that 
are identified as follow-on actions that are: (1) Related to the 
preceding required action, and (2) are on-condition actions that 
further investigate the nature of any condition found. Related 
investigative actions could include, for example, inspections and 
operational tests.
    In addition, the phrase ``corrective actions'' is used in this 
proposed AD. ``Corrective actions'' are those actions that are on-
condition actions that correct or address any condition found. 
Corrective actions could include, for example, repairs, removal and 
replacement, and modifications.
    Accomplishment of the inspection required by AD 2009-19-05, 
Amendment 39-16022 (74 FR 48138, September 22, 2009), would terminate 
the requirements of the post-replacement inspections required by 
paragraph (j) of this proposed AD.

Differences Between the Proposed AD and the Service Information

    Boeing Service Bulletin 747-53A2784, Revision 1, dated September 
14, 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.

Costs of Compliance

    We estimate that this proposed AD affects 29 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
--------------------------------------------------------------------------------------------------------------------------------------------------------
Measurement.......................  1 work-hour x $85 per      $0....................  $85......................  $2,465.
                                     hour = $85.
Inspection and web replacement....  208 work-hours x $85 per   Up to $21,887.........  Up to $39,567............  Up to $1,147,443.
                                     hour = $17,680.
Post-replacement inspection.......  135 work-hours x $85 per   $0....................  $11,475 per inspection     $332,775 per inspection cycle.
                                     hour = $11,475 per                                 cycle.
                                     inspection cycle.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for the on-condition crack repairs specified in this 
proposed AD.

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-2012-0498; Directorate Identifier 
2011-NM-212-AD.

(a) Comments Due Date

    We must receive comments by July 27, 2012.

[[Page 34883]]

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 747-400, -400D, and 
-400F series airplanes, certificated in any category, as specified 
in Boeing Service Bulletin 747-53A2784, Revision 1, dated September 
14, 2011.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by reports of crown frame web cracking at 
left buttock line (LBL) 15.0, station (STA) 320. We are proposing 
this AD to prevent complete fracture of the crown frame assembly, 
and consequent damage to the skin and in-flight decompression of the 
airplane.

(f) Compliance

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

(g) Crown Frame Web Measurement

    At the applicable compliance time specified in paragraph 1.E., 
``Compliance,'' of Boeing Service Bulletin 747-53A2784, Revision 1, 
dated September 14, 2011, except as specified in paragraph (k)(1) of 
this AD, measure the thickness of the crown frame web at station 
(STA) 320, in accordance with the Accomplishment Instructions of 
Boeing Service Bulletin 747-53A2784, Revision 1, dated September 14, 
2011. For airplanes with a 0.136 to 0.145-inch-thick web, no further 
action is required by this AD.

(h) Detailed Inspection and Web Replacement With No Web Repair Doubler

    For airplanes on which the web measures 0.078- to 0.083-inch 
thick during the measurement required by paragraph (g) of this AD, 
and on which repair doubler is not installed: At the applicable time 
specified in paragraph 1.E., ``Compliance,'' of Boeing Service 
Bulletin 747-53A2784, Revision 1, dated September 14, 2011, except 
as specified in paragraph (k)(1) of this AD, do a detailed 
inspection for cracks and a general visual inspection for missing 
fasteners of the crown frame web at STA 320; and do all applicable 
related investigative and corrective actions; in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 747-53A2784, 
Revision 1, dated September 14, 2011, except as specified in 
paragraph (k)(2) of this AD. Do the applicable related investigative 
and corrective actions at the applicable times in paragraph 1.E., 
``Compliance,'' of Boeing Service Bulletin 747-53A2784, Revision 1, 
dated September 14, 2011, except as specified in paragraph (k)(1) of 
this AD. Boeing Service Bulletin 747-53A2784, Revision 1, dated 
September 14, 2011, provides options for accomplishing the actions 
that are required for airplanes on which no cracking is found in the 
crown frame web.

(i) Detailed Inspection and Web Replacement With Web Repair Doubler

    For airplanes on which the web measures 0.078- to 0.083-inch 
thick during the measurement required by paragraph (g) of this AD, 
and on which a repair doubler is installed: At the applicable 
compliance time specified in paragraph 1.E., ``Compliance,'' of 
Boeing Service Bulletin 747-53A2784, Revision 1, dated September 14, 
2011, except as specified in paragraph (k)(1) of this AD, do the 
actions specified in paragraphs (i)(1) and (i)(2) of this AD, and do 
all applicable corrective actions, in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 747-53A2784, 
Revision 1, dated September 14, 2011, except as provided by 
paragraph (k)(2) of this AD. Do all applicable corrective actions 
before further flight.
    (1) Replace the web with a new web and do all applicable related 
investigative actions.
    (2) Do a detailed inspection for cracks in the upper or lower 
chord of the crown frame web at STA 320.

(j) Post-Replacement Repetitive Inspections of Replaced Web

    Following any web replacement required by this AD, at the times 
specified in paragraph 1.E., ``Compliance,'' of Boeing Service 
Bulletin 747-53A2784, Revision 1, dated September 14, 2011: Do a 
detailed inspection for cracks of the web, upper chord, lower chord, 
and lower chord splice, and do all applicable corrective actions, in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 747-53A2784, Revision 1, dated September 14, 2011, except 
as provided by paragraph (k)(2) of this AD. Do all applicable 
corrective actions before further flight. If no crack is found, 
repeat the inspection thereafter at the intervals specified in 
paragraph 1.E., ``Compliance,'' of Boeing Service Bulletin 747-
53A2784, Revision 1, dated September 14, 2011. Accomplishment of the 
inspections required by AD 2009-19-05, Amendment 39-16022 (74 FR 
48138, September 22, 2009), terminates the requirements of this 
paragraph.

(k) Exceptions to the Service Information

    (1) Where Boeing Service Bulletin 747-53A2784, Revision 1, dated 
September 14, 2011, specifies a compliance time ``after the original 
issue date of the service bulletin,'' this AD requires compliance 
within the specified compliance time after the effective date of 
this AD.
    (2) Where Boeing Service Bulletin 747-53A2784, Revision 1, dated 
September 14, 2011, specifies to contact Boeing for appropriate 
action, accomplish applicable actions before further flight using a 
method approved in accordance with the procedures specified in 
paragraph (l) of this AD.

(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.

(m) Related Information

    (1) For more information about this AD, contact Bill Ashforth, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle ACO, 
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; telephone 
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-2012-0498). 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 May 31, 2012.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-14253 Filed 6-11-12; 8:45 am]
BILLING CODE 4910-13-P


