

[Federal Register: September 21, 2007 (Volume 72, Number 183)]
[Rules and Regulations]               
[Page 53939-53942]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21se07-13]                         

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-29263; Directorate Identifier 2007-NM-198-AD; 
Amendment 39-15210; AD 2007-19-19]
RIN 2120-AA64

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

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

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD) that applies to certain Boeing Model 747 series airplanes. The 
existing AD currently requires repetitive inspections and torque checks 
of the hanger fittings and strut forward bulkhead of the forward engine 
mount and adjacent support structure, and corrective actions if 
necessary. The existing AD also currently requires a terminating action 
for the repetitive inspections and checks. This new AD requires, among 
other actions, new repetitive inspections in the existing area and new 
areas. This new AD also provides for an optional inspection and no 
longer allows the existing fastener replacement to terminate repetitive 
inspections. This AD results from new reports of under-torqued or loose 
fasteners, a cracked bulkhead chord, and a fractured back-up angle 
after operators accomplished the terminating action required by the 
existing AD. We are issuing this AD to detect and correct loose 
fasteners and/or damaged or cracked hanger fittings, back-up angles, 
and bulkhead of the forward engine mount, which could lead to failure 
of the hanger fitting and bulkhead and consequent separation of the 
engine from the airplane.

DATES: This AD becomes effective October 9, 2007.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of October 9, 
2007.
    On December 6, 2000 (65 FR 69862, November 21, 2000), the Director 
of the Federal Register approved the incorporation by reference of 
Boeing Alert Service Bulletin 747-54A2203, dated August 31, 2000.
    We must receive any comments on this AD by November 20, 2007.

ADDRESSES: Use one of the following addresses to submit comments on 
this AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 

the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov
 and follow the instructions for sending your 

comments electronically.
     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.
     Fax: (202) 493-2251.
     Hand Delivery: Room W12-140 on the ground floor of the 
West Building, 1200 New Jersey Avenue, SE., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT: Tamara Anderson, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6421; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: 

Discussion

    On July 13, 2001, we issued AD 2001-15-02, amendment 39-12336 (66 
FR 37884, July 20, 2001). That AD applies to certain Boeing Model 747 
series airplanes. That AD requires repetitive inspections and torque 
checks of the hanger fittings and strut forward bulkhead of the forward 
engine mount and adjacent support structure, and corrective actions if 
necessary. That AD also requires a terminating action for the 
repetitive inspections and checks. That AD resulted from reports 
indicating the detection of loose fasteners of the hanger fittings and 
strut forward bulkhead of the forward engine mount. The actions 
specified in that AD are intended to prevent loose fasteners and 
associated damage to the hanger fittings

[[Page 53940]]

and bulkhead of the forward engine mount, which could result in 
separation of the engine from the airplane.

Actions Since AD Was Issued

    Since we issued that AD, we have received new reports of under-
torqued or loose fasteners after operators accomplished the terminating 
action required by AD 2001-15-02 (i.e., Part 6 specified in Boeing 
Alert Service Bulletin 747-54A2203, dated August 31, 2000). In 
addition, we have received a report of a crack approximately 1.5-inch 
in length in the bulkhead chord adjacent to an upper fastener on a 
number 2 strut with approximately 20,050 total flight cycles and 
110,000 total flight hours. Further investigation revealed that the 
back-up angle inside the strut adjacent to the crack had fractured at 
its bend radius. The fracture initiated as a result of fatigue at 
multiple locations on the inner diameter of the bend radius. The cause 
of the loose fasteners of the hanger fittings of the bulkhead of the 
forward engine mount is their location in an area of high vibration and 
the design of the bulkhead. Loose fasteners and/or damaged or cracked 
hanger fittings, back-up angles, and bulkhead of the forward engine 
mount, if not corrected, could lead to failure of the hanger fitting 
and bulkhead and consequent separation of the engine from the airplane.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-54A2203, 
Revision 1, dated August 9, 2007. The service information describes the 
following new procedures:
     Repetitive detailed inspections of the torque stripes and 
bulkhead of the forward engine mount and the adjacent support structure 
on the inboard and outboard struts and repetitive torque inspections 
(checks) of the bulkhead for cracks and/or fretting damage of the 
hanger fittings and bulkhead and for loose or under-torqued fasteners, 
as applicable; and applicable related investigative and corrective 
actions (i.e., Part 2 of the Accomplishment Instructions).
     Repetitive high frequency eddy current (HFEC), detailed, 
or fluorescent penetrant inspections of the bulkhead of the forward 
engine mount on the inboard and outboard struts for cracks of the 
bulkhead chords, evidence of a fractured internal angle, or cracks/
fracture of the internal angles; as applicable (i.e., Part 8 of the 
Accomplishment Instructions); and detailed and HFEC inspections to 
detect cracks or fracture of the internal angle and stiffener (i.e., 
Part 7 of the Accomplishment Instructions), and applicable related 
investigative and corrective actions.
    The related investigative actions involve doing applicable 
inspections described previously. The corrective actions include 
applying optional torque stripes; reworking, repairing, and/or 
replacing any discrepant part with a new part; replacing all fasteners 
with new fasteners; and contacting Boeing for certain conditions; as 
applicable.
    For the inspections specified in Parts 2 and 8 of the 
Accomplishment Instructions, the service information specifies an 
initial compliance time of 90 days and repeat intervals of 6 and 18 
months, depending on the inspection type. For the inspections specified 
in Part 7 of the Accomplishment Instructions, the service information 
specifies an initial compliance time of 18 months and repeat intervals 
of 36 months. The service bulletin specifies a compliance time of 
before further flight or 18 months for doing the related investigative 
and corrective actions, as applicable.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other airplanes of the same type design. For this reason, we 
are issuing this AD to supersede AD 2001-15-02. This new AD retains the 
required fastener replacement, except that action no longer terminates 
any repetitive inspections and torque inspections (checks). This AD 
also requires accomplishing the actions specified in Parts 2 and 8 of 
the Accomplishment Instructions of the service information described 
previously, except as discussed under ``Differences Between the AD and 
Service Information.'' This AD also provides, as an option, the 
inspections specified in Part 7 of the Accomplishment Instructions of 
the service information described previously.

Interim Action

    This is considered to be interim action. We are currently 
considering requiring the inspections and applicable related 
investigative and corrective actions specified in Part 7 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
54A2203, Revision 1. However, the planned compliance time for the 
inspections is sufficiently long so that notice and opportunity for 
prior public comment will be practicable.

Differences Between the AD and Service Information

    The service information specifies to contact the manufacturer for 
instructions on how to repair certain conditions, but this AD requires 
repairing those conditions in one of the following ways:
     Using a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by an Authorized Representative 
for the Boeing Commercial Airplanes Delegation Option Authorization 
Organization whom we have authorized to make those findings.

Change to Existing AD

    This AD will retain certain requirements of AD 2001-15-02. Since AD 
2001-15-02 was issued, we have revised the AD format and rearranged 
certain paragraphs. As a result, we reidentified paragraph (c) of AD 
2001-15-02 as paragraph (f) in this AD.
    Boeing Commercial Airplanes has received a Delegation Option 
Authorization (DOA). We have revised paragraph (f) of this AD to 
delegate the authority to approve an alternative method of compliance 
for any repair required by this AD to an Authorized Representative for 
the Boeing Commercial Airplanes DOA rather than a Designated 
Engineering Representative (DER).

FAA's Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD; therefore, providing notice and opportunity for public comment 
before the AD is issued is impracticable, and good cause exists to make 
this AD effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements that affect 
flight safety and was not preceded by notice and an opportunity for 
public comment; however, we invite you to submit any relevant written 
data, views, or arguments regarding this AD. Send your comments to an 
address listed in the ADDRESSES section. Include ``Docket No. FAA-2007-
29263; Directorate Identifier 2007-NM-198-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the AD that might 
suggest a need to modify it.
    We will post all comments we receive, without change, to http://dms.dot.gov
, including any personal information you provide. We will 

also

[[Page 53941]]

post a report summarizing each substantive verbal contact with FAA 
personnel concerning this AD. Using the search function of that web 
site, anyone can find and read the comments in any of our dockets, 
including the name of the individual who sent the comment (or signed 
the comment on behalf of an association, business, labor union, etc.). 
You may review the DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (65 FR 19477-78), or you may visit 
http://dms.dot.gov.


Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov
, or in person at the Docket Operations office between 9 

a.m. and 5 p.m., Monday through Friday, except Federal holidays. The 
Docket Operations office (telephone (800) 647-5527) is located on the 
ground level of the West Building at the DOT street address stated in 
the ADDRESSES section. Comments will be available in the AD docket 
shortly after the Docket Management System receives them.

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 AD will not have federalism 
implications under Executive Order 13132. This AD will not have a 
substantial direct effect on the States, on the relationship between 
the national government and the States, or on the distribution of power 
and responsibilities among the various levels of government.
    For the reasons discussed above, I certify that the 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 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.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends part 39 of the Federal Aviation Regulations (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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
removing amendment 39-12336 (66 FR 37884, July 20, 2001) and adding the 
following new airworthiness directive (AD):

2007-19-19 Boeing: Docket No. FAA-2007-29263; Directorate Identifier 
2007-NM-198-AD; Amendment 39-15210.

Effective Date

    (a) This AD becomes effective October 9, 2007.

Affected ADs

    (b) This AD supersedes AD 2001-15-02.

Applicability

    (c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series 
airplanes, certificated in any category; as identified in Boeing 
Alert Service Bulletin 747-54A2203, Revision 1, dated August 9, 
2007.

Unsafe Condition

    (d) This AD results from new reports of under-torqued or loose 
fasteners, a cracked bulkhead chord, and a fractured back-up angle 
after operators accomplished the terminating action required by the 
existing AD. We are issuing this AD to detect and correct loose 
fasteners and/or damaged or cracked hanger fittings, back-up angles, 
and bulkhead of the forward engine mount, which could lead to 
failure of the hanger fitting and bulkhead and consequent separation 
of the engine from the airplane.

Compliance

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

Certain Requirement of AD 2001-15-02

    (f) Within 60 months after August 24, 2001 (the effective date 
of AD 2001-15-02): Accomplish all actions specified in Part 6 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
54A2203, dated August 31, 2000. Where the alert service bulletin 
specifies that the manufacturer may be contacted for disposition of 
certain corrective actions (rework or replacement of fittings), this 
AD requires such rework and/or replacement to be done in accordance 
with a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO); or in accordance with data meeting the 
type certification basis of the airplane approved by a Boeing 
Company Designated Engineering Representative (DER) who has been 
authorized by the Manager, Seattle ACO, to make such findings. For a 
repair method to be approved by the Manager, Seattle ACO, as 
required by this paragraph, the Manager's approval letter must 
specifically reference this AD. As of the effective date of this AD, 
the rework and/or replacement must be done using a method approved 
in accordance with the procedures specified in paragraph (k) of this 
AD.

    Note 1: Installation of two BACW10BP*APU washers on Group A 
fasteners accomplished during modification in accordance with Boeing 
Service Bulletin 747-54A2159, dated November 3, 1994, Revision 1, 
dated June 1, 1995, or Revision 2, dated March 14, 1996; and pin or 
bolt protrusion as specified in the 747 Structural Repair Manual, 
Chapter 51-30-02 (both referenced in Boeing Alert Service Bulletin 
747-54A2203, dated August 31, 2000); is considered acceptable for 
compliance with the action required by paragraph (f) of this AD.

New Actions Required by This AD

Inspections and Related Investigative and Corrective Actions

    (g) Except as provided by paragraphs (i) and (j) of this AD: At 
the applicable compliance times and repeat intervals listed in 
Tables 1 and 2 of paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 747-54A2203, Revision 1, dated August 9, 2007, do 
the inspections and applicable related investigative and corrective 
actions by accomplishing all the actions specified in Parts 2 and 8 
of the Accomplishment Instructions of the service bulletin.

Optional Initial and Repetitive Inspections and Related Investigative 
and Corrective Actions

    (h) Do the initial and repetitive inspections and related 
investigative and corrective actions by accomplishing all the 
actions specified in Part 7 of the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-54A2203, Revision 1, dated August 
9, 2007, except as provided by paragraph (j) of this AD.

[[Page 53942]]

Exceptions to Service Bulletin

    (i) Where Boeing Alert Service Bulletin 747-54A2203, Revision 1, 
dated August 9, 2007, 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.
    (j) Where Boeing Alert Service Bulletin 747-54A2203, Revision 1, 
dated August 9, 2007, specifies to contact Boeing for appropriate 
action, this AD requires, before further flight, repair of the 
discrepancy or replacement of the discrepant part using a method 
approved in accordance with the procedures specified in paragraph 
(k) of this AD.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (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 appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (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 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.

Material Incorporated by Reference

    (l) You must use Boeing Alert Service Bulletin 747-54A2203, 
dated August 31, 2000; and Boeing Alert Service Bulletin 747-
54A2203, Revision 1, dated August 9, 2007; to perform the actions 
that are required by this AD, unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of Boeing Alert Service Bulletin 747-
54A2203, Revision 1, dated August 9, 2007, in accordance with 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) On December 6, 2000 (65 FR 69862, November 21, 2000), the 
Director of the Federal Register approved the incorporation by 
reference of Boeing Alert Service Bulletin 747-54A2203, dated August 
31, 2000.
    (3) Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for a copy of this service information. You 
may review copies at the FAA, Transport Airplane Directorate, 1601 
Lind Avenue, SW., Renton, Washington; or at the National Archives 
and Records Administration (NARA). For information on the 
availability of this material at NARA, call 202-741-6030, or go to: 
http://www.archives.gov/federal-register/cfr/ibr-locations.html.


    Issued in Renton, Washington, on September 14, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-18541 Filed 9-20-07; 8:45 am]

BILLING CODE 4910-13-P
