
[Federal Register: September 23, 2008 (Volume 73, Number 185)]
[Proposed Rules]               
[Page 54755-54757]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr23se08-31]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1006; Directorate Identifier 2008-NM-110-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
200B, 747-200C, 747-200F, 747-300, 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 747-100, 747-100B, 
747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series 
airplanes. The existing AD currently requires an inspection to 
determine if acceptable external skin doublers are installed at the 
stringer 6 (S-6) lap splices, between station (STA) 340 and STA 400. 
For airplanes without the acceptable external skin doublers, the 
existing AD requires repetitive related investigative actions and 
corrective actions if necessary. The existing AD also provides an 
optional terminating modification for the repetitive related 
investigative actions. This proposed AD would mandate the optional 
terminating modification. This proposed AD results from a report of 
cracked fastener holes at the right S-6 lap splice between STA 340 and 
STA 380. We are proposing this AD to prevent cracking in the fuselage 
skin, which could result in rapid decompression and loss of structural 
integrity of the airplane.

DATES: We must receive comments on this proposed AD by November 7, 
2008.

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.

[[Page 54756]]

     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.
    For service information identified in this AD, contact Boeing 
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

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-2008-1006; 
Directorate Identifier 2008-NM-110-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 May 13, 2008, we issued AD 2008-10-15, amendment 39-15522 (73 FR 
29042, May 20, 2008), for certain Boeing Model 747-100, 747-100B, 747-
200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series airplanes. 
That AD requires an inspection to determine if acceptable external skin 
doublers are installed at the stringer 6 (S-6) lap splices, between 
station (STA) 340 and STA 400. For airplanes without the acceptable 
external skin doublers, that AD requires repetitive related 
investigative actions and corrective actions if necessary. That AD also 
provides an optional terminating modification for the repetitive 
related investigative actions. That AD resulted from a report of 
cracked fastener holes at the right S-6 lap splice between STA 340 and 
STA 380. We issued that AD to detect and correct cracking in the 
fuselage skin, which could result in rapid decompression and loss of 
the airplane.

Actions Since Existing AD Was Issued

    The preamble to AD 2008-10-15 specifies that we consider the 
requirements ``interim action'' and that we were considering requiring 
the modification (installation of acceptable external skin doublers), 
which would terminate the repetitive related investigative actions. We 
now have determined that further rulemaking is indeed necessary, and 
this proposed AD follows from that determination.

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 other airplanes of the 
same type design. For this reason, we are proposing this AD, which 
would supersede AD 2008-10-15 and would retain the requirements of the 
existing AD. This proposed AD would also mandate the terminating action 
that was optional in AD 2008-10-15.

Costs of Compliance

    There are about 501 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 174 airplanes of 
U.S. registry.
    The inspection for acceptable external skin doublers that is 
required by AD 2008-10-15 and retained in this proposed AD takes about 
2 work hours per airplane, at an average labor rate of $80 per work 
hour. Based on these figures, the estimated cost of the inspection for 
U.S. operators is $27,840, or $160 per airplane.
    The cost for the proposed terminating action depends upon the 
results of the inspections. Therefore, we cannot calculate those costs 
because we do not know what doubler conditions operators will find.

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, 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:

[[Page 54757]]

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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
removing amendment 39-15522 (73 FR 29042, May 20, 2008) and adding the 
following new airworthiness directive (AD):

Boeing: Docket No. FAA-2008-1006; Directorate Identifier 2008-NM-
110-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by November 
7, 2008.

Affected ADs

    (b) This AD supersedes AD 2008-10-15.

Applicability

    (c) This AD applies to Boeing Model 747-100, 747-100B, 747-200B, 
747-200C, 747-200F, 747-300, 747SR, and 747SP series airplanes, 
certificated in any category; as identified in Boeing Alert Service 
Bulletin 747-53A2748, dated May 9, 2008.

Unsafe Condition

    (d) This AD results from a report of cracked fastener holes at 
the right stringer 6 (S-6) lap splice between station (STA) 340 and 
STA 380. We are issuing this AD to prevent cracking in the fuselage 
skin, which could result in rapid decompression and loss of 
structural integrity of 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.

Requirements of AD 2008-10-15

Service Bulletin Reference Paragraph

    (f) The term ``alert service bulletin,'' as used in this AD, 
means the Accomplishment Instructions of Boeing Alert Service 
Bulletin 747-53A2748, dated May 9, 2008.

Inspection for Acceptable External Skin Doublers

    (g) For airplanes identified as Group 1, Configuration 2, in 
Boeing Alert Service Bulletin 747-53A2748, dated May 9, 2008: At the 
latest of the times specified in paragraphs (g)(1), (g)(2), and 
(g)(3) of this AD, do an external general visual inspection to 
determine if acceptable external skin doublers are installed at the 
left- and right-side S-6 lap splices, in accordance with Part 1 of 
the alert service bulletin.
    (1) Prior to the accumulation of 10,000 total flight cycles.
    (2) Within 8,000 flight cycles after a modification was done in 
accordance with Boeing Service Bulletin 747-53-2253.
    (3) Within 15 days or 100 flight cycles after May 20, 2008 (the 
effective date of AD 2008-10-15), whichever occurs first.

Acceptable External Skin Doublers Found at Both Sides

    (h) If, during the inspection required by paragraph (g) of this 
AD, acceptable external skin doublers in accordance with the alert 
service bulletin are found installed at both the left- and right-
side S-6 lap splices, no further work is required by this AD.

Acceptable External Skin Doublers Not Found--Repetitive Related 
Investigative Actions and Corrective Actions

    (i) If, during the inspection required by paragraph (g) of this 
AD, acceptable external skin doublers in accordance with alert 
service bulletin are not found installed at either the left- or 
right-side S-6 lap splice: Before further flight, do all applicable 
related investigative and corrective actions by doing all actions 
specified in Part 2 of the alert service bulletin. Repeat the 
applicable related investigative actions thereafter at intervals not 
to exceed 300 flight cycles until the modification specified in 
paragraph (j) of this AD is done.

New Requirement of This AD

Terminating Modification

    (j) If, during the inspection required by paragraph (g) of this 
AD, acceptable external skin doublers as specified in the alert 
service bulletin are not found installed at either the left- or 
right-side S-6 lap splice: Within 3,000 flight cycles after doing 
the initial related investigative actions in paragraph (i) of this 
AD, or within 300 flight cycles after the effective date of this AD, 
whichever occurs later, install acceptable external skin doublers at 
both the left- and right-side S-6 lap splices, as applicable. The 
installation of the acceptable skin doublers is required on the side 
of the airplane that does not have the doublers already. The 
installation includes doing an open-hole high-frequency eddy current 
(HFEC) inspection of the skin for cracking, and trimming out 
cracking as applicable. Do all actions in accordance with the alert 
service bulletin. Doing this installation terminates the repetitive 
related investigative actions required by paragraph (i) of this AD.

    Note 1: The alert service bulletin refers to Boeing Service 
Bulletins 747-53-2253, Revision 3, dated March 24, 1994; and 747-53-
2272, Revision 18, dated May 16, 2002; as additional sources of 
service information for accomplishment of the modification 
(installation of acceptable external skin doublers).


    Note 2: AD 90-06-06, amendment 39-6490, requires, among other 
actions, a modification as specified in Boeing Service Bulletin 747-
53-2253, dated December 14, 1984.


    Note 3: AD 90-23-14, amendment 39-6801, requires inspections as 
specified in Boeing Service Bulletin 747-53-2253, Revision 2, dated 
March 29, 1990.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, ATTN: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, 
FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6437; fax (425) 917-6590; has the 
authority to approve AMOCs for this AD, if requested using 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.
    (4) AMOCs approved previously in accordance with AD 2008-10-15 
are approved as AMOCs for the corresponding provisions of this AD.

    Issued in Renton, Washington, on September 12, 2008.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-22211 Filed 9-22-08; 8:45 am]

BILLING CODE 4910-13-P
