
[Federal Register: August 5, 2009 (Volume 74, Number 149)]
[Proposed Rules]               
[Page 38995-38998]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr05au09-30]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0682; Directorate Identifier 2008-NM-200-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-300, 747-400, 747SR, and 747SP Series Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) that applies to certain Boeing Model 747 airplanes. The 
existing AD currently requires repetitive inspections for cracking, and 
repair as necessary, of lower lobe body frames (sections 42 and 46) of 
the fuselage. The existing AD also provides for optional modification 
of the frames, which terminates the repetitive inspections. This 
proposed AD would require additional repetitive inspections for 
cracking of certain fuselage frames, and corrective actions if 
necessary. This proposed AD would also revise the AD applicability. 
This proposed AD results from a new report of a crack found in a body 
frame with a tapered side guide bracket at fuselage station 1800, 
located on the left side between stringers 39 and 40; the frame was 
severed. We are proposing this AD to detect and correct the loss of 
structural integrity of the fuselage, which could result in rapid 
depressurization of the airplane.

DATES: We must receive comments on this proposed AD by September 21, 
2009.

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: 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.

[[Page 38996]]

    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; e-mail me.boecom@boeing.com; 
Internet https://www.myboeingfleet.com. You may review copies of the 
referenced service information at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information 
on the availability of this material at the FAA, call 425-227-1221 or 
425-227-1152.

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

FOR FURTHER INFORMATION CONTACT: Ivan Li, Aerospace Engineer, Airframe 
Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind 
Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437; 
fax (425) 917-6590.

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-2009-0682; 
Directorate Identifier 2008-NM-200-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 August 4, 1986, we issued AD 86-18-01, amendment 39-5390 (51 FR 
28691, August 11, 1986), for certain Boeing Model 747 airplanes. That 
AD requires repetitive inspections for cracking, and repair as 
necessary, of lower lobe body frames (sections 42 and 46) of the 
fuselage. That AD also provides for optional modification of the 
frames, which terminates the repetitive inspections. That AD resulted 
from a finding of numerous body frame cracks in the lower lobe of the 
fuselage. We issued that AD to prevent failure of the structure, which 
could lead to rapid decompression of the airplane.

Actions Since Existing AD was Issued

    Since we issued AD 86-18-01, we received a report of a crack found 
in a body frame with a tapered side guide bracket at fuselage station 
1800. The body frame was located on the left side between stringers 39 
and 40 and was severed. Investigation revealed that frames with tapered 
side guide brackets and frames with the optional terminating action 
incorporated are also susceptible to cracking. As a result, we have 
determined that additional inspections are necessary, as specified in 
the service information described below. In addition, we have 
determined that it is necessary to revise the AD applicability to 
include the affected frames on certain other airplanes, as specified in 
the service information described below.

Other Related Rulemaking

    On February 16, 2006, we issued AD 2006-05-02, amendment 39-14499 
(71 FR 10605, March 2, 2006), for all Boeing Model 747-200F, 747-200C, 
747-400, 747-400D, and 747-400F series airplanes. That AD requires 
repetitive inspections for cracking of certain fuselage internal 
structure, and repair if necessary. That AD resulted from fatigue tests 
and analysis that identified areas of the fuselage where fatigue cracks 
can occur. We issued that AD to prevent loss of the structural 
integrity of the fuselage, which could result in rapid depressurization 
of the airplane.
    On September 26, 2005, we issued AD 2005-20-30, amendment 39-14327 
(70 FR 59252, October 12, 2005), for certain Boeing Model 747-100, 747-
100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR series 
airplanes. That AD supersedes an existing AD and requires repetitive 
inspections to detect cracks in various areas of the fuselage internal 
structure, and repair if necessary. That AD also requires repetitive 
inspections of additional areas of the fuselage internal structure, and 
related investigative/corrective actions if necessary. That AD also 
removes certain requirements from the existing AD. That AD resulted 
from fatigue testing of the fuselage structure of a Boeing Model 747SR 
series airplane. We issued that AD to prevent the loss of the 
structural integrity of the fuselage, which could result in rapid 
depressurization of the airplane.
    The inspections specified in this proposed AD are not necessary on 
airplanes on which the repetitive inspections have been done in 
accordance with AD 2005-20-30 and AD 2006-05-02.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-53A2749, dated 
September 25, 2008. The service bulletin describes procedures for a 
detailed inspection for cracking of the inner chord and vertical web of 
the left and right side body frames from fuselage stations 1500 to 
1800, stringers 39 to 40; and corrective actions if necessary. The 
corrective action is repairing any crack found.
    For airplanes that have accumulated 22,000 total flight cycles or 
more, the service bulletin specifies that no work is necessary. Those 
airplanes are being inspected per the requirements of AD 2005-20-30 or 
AD 2006-05-02, as applicable.
    For all other airplanes, the compliance time for the detailed 
inspection for cracking of the inner chord and vertical web is before 
the accumulation of 10,000 total flight cycles, or 10,000 flight cycles 
after installation of a tapered strap, or within a specified grace 
period. The grace period is either 2,000 flight cycles after the date 
on the service bulletin or 3,000 flight cycles after the most recent 
inspection, depending on the airplane configuration and inspection 
status.
    The service bulletin specifies repeating the inspection every 3,000 
flight cycles until the accumulation of 22,000 total flight cycles.
    The service bulletin also includes doing a detailed inspection for 
cracks in any existing repair and the adjacent structure, and 
corrective actions if necessary. The service bulletin also provides for 
optional installation of a tapered strap if no crack is found, which 
extends the repetitive inspection interval.
    The service bulletin specifies doing the detailed inspection of the 
repair within 3,000 flight cycles or 10,000 flight cycles after the 
repair was done, depending on whether a tapered strap is installed. The 
service bulletin also specifies repeating the inspection every 3,000 
flight cycles until the accumulation of 22,000 total flight cycles.

[[Page 38997]]

    The service bulletin also recommends as a corrective action 
contacting Boeing before further flight for repair instructions if 
cracking is found on the installed repair, tapered strap, or adjacent 
structure.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to develop on airplanes of the same 
type design. For this reason, we are proposing this AD, which would 
supersede AD 86-18-01 and would retain the requirements of the existing 
AD. This proposed AD would also require accomplishing the actions 
specified in Boeing Alert Service Bulletin 747-53A2749, dated September 
25, 2008, described previously.

Change to Existing AD

    This proposed AD would retain the requirements of AD 86-18-01. 
Since AD 86-18-01 was issued, the AD format has been revised, and 
certain paragraphs have been rearranged. As a result, the corresponding 
paragraph identifiers have changed in this proposed AD, as listed in 
the following table:

                      Revised Paragraph Identifiers
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                                           Corresponding requirement in
       Requirement in AD  86-18-01               this proposed  AD
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Paragraph A.............................  Paragraph (g).
Paragraph B.............................  Paragraph (h).
Paragraph C.............................  Paragraph (i).
Paragraph D.............................  Paragraph (j).
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Costs of Compliance

    There are about 237 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

                                                 Estimated Costs
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                                                                                  Number of
                                                 Average                            U.S.-
             Action                Work hours   labor rate   Cost per airplane    registered      Fleet cost
                                                 per hour                         airplanes
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Inspections (required by AD 86-           370          $80  $29,600, per                 112  $3,315,200, per
 18-01).                                                     inspection cycle.                 inspection cycle.
Additional inspections (new                 6           80  $480, per                     87  $41,760, per
 proposed action).                                           inspection cycle.                 inspection cycle.
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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 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); and
    3. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

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 removing amendment 39-5390 (51 FR 
28691, August 11, 1986), and adding the following new AD:

Boeing: Docket No. FAA-2009-0682; Directorate Identifier 2008-NM-
200-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by September 
21, 2009.

Affected ADs

    (b) This AD supersedes AD 86-18-01.

Applicability

    (c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-300, 747-400, 747SR, and 747SP series airplanes, 
certificated in any category, as identified in Boeing Alert Service 
Bulletin 747-53A2749, dated September 25, 2008.

Subject

    (d) Air Transport Association (ATA) of America Code 53: 
Fuselage.

Unsafe Condition

    (e) This AD results from a report of a crack found in a body 
frame with a tapered side guide bracket at fuselage station 1800, 
located on the left side between stringers 39 and 40; the frame was 
severed. The Federal Aviation Administration is issuing this AD to 
detect and correct the loss of structural integrity of the fuselage, 
which could result in rapid depressurization of the airplane.

Compliance

    (f) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

[[Page 38998]]

Restatement of Requirements of AD 86-18-01, with Revised Service 
Information

Repetitive Inspections

    (g) For airplanes listed in Boeing Alert Service Bulletin 747-
53A2237, Revision 1, dated March 28, 1986: Perform a detailed visual 
inspection for frame cracking from fuselage section 540 to 760, and 
1820 to 1900, stringers 35 left to 42 left, in accordance with 
Section III of Boeing Alert Service Bulletin 747-53A2237, Revision 
1, dated March 28, 1986. Do the inspection at the time specified in 
paragraph (g)(1), (g)(2), or (g)(3) of this AD, as applicable. If 
any crack is found, repair in accordance with a method approved by 
the Manager, Seattle Aircraft Certification Office (ACO), FAA, or 
using a method approved in accordance with the procedures specified 
in paragraph (p) of this AD. Repeat the inspection at intervals not 
to exceed 3,000 landings until the terminating action specified in 
paragraph (g)(4) or (k) of this AD is performed.
    (1) Within 300 landings for airplanes that have accumulated more 
than 12,000 landings on September 17, 1986 (the effective date of AD 
86-18-01, amendment 39-5390).
    (2) Within 800 landings for airplanes that have accumulated 
10,000 to 12,000 landings on September 17, 1986.
    (3) Within 800 landings or prior to the accumulation of 10,000 
landings, whichever occurs later, for airplanes that have 
accumulated less than 10,000 landings on September 17, 1986.
    (4) Modification of the frames before the effective date of this 
AD in accordance with Boeing Alert Service Bulletin 747-53A2237, 
Revision 1, dated March 28, 1986, constitutes terminating action for 
the repetitive inspections required by paragraph (g) of this AD.
    (h) For airplanes listed in Boeing Alert Service Bulletin 747-
53A2259, Revision 1, dated April 18, 1986: Perform a visual 
inspection of cargo side guide support brackets from fuselage 
station 1500 to 1800, right and left hand side, for a proper 
machined taper in accordance with Section III of Boeing Alert 
Service Bulletin 747-53A2259, Revision 1, dated April 18, 1986. Do 
the inspection at the time specified in paragraph (h)(1), (h)(2), or 
(h)(3) of this AD, as applicable. If any cargo side guide support 
bracket is improperly tapered, perform a detailed visual inspection 
of the frame area adjacent to the untapered bracket for cracking in 
accordance with Boeing Alert Service Bulletin 747-53A2259, Revision 
1, dated April 18, 1986. If any crack is found, repair in accordance 
with a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA, or using a method approved in 
accordance with the procedures specified in paragraph (p) of this 
AD. Repeat the detailed visual inspection at intervals not to exceed 
3,000 landings until the terminating action specified in paragraph 
(h)(4) of this AD is performed. Accomplishment of the inspections 
required by paragraph (k) of this AD terminates the inspections 
required by this paragraph.
    (1) Within 300 landings for airplanes that have accumulated more 
than 12,000 landings on September 17, 1986 (the effective date of AD 
86-18-01, amendment 39-5390).
    (2) Within 800 landings for airplanes that have accumulated 
10,000 to 12,000 landings on September 17, 1986.
    (3) Within 800 landings or prior to the accumulation of 10,000 
landings, whichever occurs later, for airplanes that have 
accumulated less than 10,000 landings on September 17, 1986.
    (4) Installation of a tapered strap adjacent to the affected 
brackets before the effective date of this AD in accordance with 
Boeing Alert Service Bulletin 747-53A2259, Revision 1, dated April 
18, 1986, constitutes terminating action for the repetitive 
inspections required by paragraph (h) of this AD.
    (i) For Boeing Model 747SR airplanes only, based on continued 
mixed operation of cabin pressure differentials, the initial 
inspection thresholds and reinspection intervals specified in AD 86-
18-01 may be multiplied by a 1.2 adjustment factor. This provision 
is not applicable to paragraphs (k), (m), and (n) of this AD.
    (j) For the purposes of complying with AD 86-18-01, the number 
of landings may be determined to equal the number of pressurization 
cycles where the cabin pressure differential was greater than 2.0 
pounds per square inch. This provision is not applicable to 
paragraphs (k), (m), and (n) of this AD.

New Requirements of this AD

Repetitive Inspections

    (k) For airplanes identified in Boeing Alert Service Bulletin 
747-53A2749, dated September 25, 2008, that have accumulated 22,000 
or fewer total flight cycles as of the effective date of this AD: Do 
initial and repetitive detailed inspections for frame cracking from 
fuselage body stations 1500 to 1800, stringers 39 to 40, by doing 
all the actions specified in the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-53A2749, dated September 25, 2008, 
except as required by paragraph (l) of this AD. Do the inspections 
and corrective actions at the times specified in paragraph 1.E. of 
Boeing Alert Service Bulletin 747-53A2749, dated September 25, 2008, 
except as required by paragraphs (m) and (n) of this AD. 
Accomplishment of the inspections required by this paragraph 
terminates the inspections required by paragraph (h) of this AD.

Exceptions to Service Bulletin Procedures

    (l) If any crack is found during any inspection required by this 
AD, and Boeing Alert Service Bulletin 747-53A2749, dated September 
25, 2008, specifies to contact Boeing for appropriate action: Before 
further flight, repair the crack using a method approved in 
accordance with the procedures specified in paragraph (p) of this 
AD.
    (m) Where Boeing Alert Service Bulletin 747-53A2749, dated 
September 25, 2008, specifies a compliance time after the date of 
the service bulletin, this AD requires compliance within the 
specified compliance time after the effective date of this AD.
    (n) Where Boeing Alert Service Bulletin 747-53A2749, dated 
September 25, 2008, specifies a compliance time related to 
accomplishing an action ``as given in Boeing Service Bulletin 747-
53A2259,'' this AD requires compliance within the specified 
compliance time after the applicable compliance time required by 
paragraph (h) of this AD.

Terminating Action

    (o) Accomplishing the repetitive frame inspections required by 
AD 2006-05-02, amendment 39-14499, or AD 2005-20-30, amendment 39-
14327, terminates the inspections required by paragraphs (g), (h), 
and (k) of this AD.

Alternative Methods of Compliance (AMOCs)

    (p)(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. Send information to 
Attn: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., 
Renton, Washington 98057-3356; telephone (425) 917-6437; fax (425) 
917-6590; or, e-mail information to 9-ANM-Seattle-ACO-AMOC-
Requests@faa.gov.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your principal maintenance inspector (PMI) or 
principal avionics inspector (PAI), as appropriate, or lacking a 
principal inspector, your local Flight Standards District Office. 
The AMOC approval letter must specifically reference this AD.
    (3) AMOCs approved previously in accordance with paragraph (A) 
of AD 86-18-01, are approved as alternative methods of compliance 
with the corresponding requirements of paragraph (g) of this AD.
    (4) AMOCs approved previously in accordance with paragraph (B) 
of AD 86-18-01, are approved as alternative methods of compliance 
with the corresponding requirements of paragraph (h) of this AD.
    (5) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by an 
Authorized Representative for the Boeing Commercial Airplanes 
Delegation Option Authorization Organization who 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.

    Issued in Renton, Washington, on July 24, 2009.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-18641 Filed 8-4-09; 8:45 am]

BILLING CODE 4910-13-P
