Airworthiness Directives; Boeing Model 747 Series Airplanes

[Federal Register Volume 70, Number 78 (Monday, April 25, 2005)]
[Rules and Regulations]
[Pages 21141-21144]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-8098]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21027; Directorate Identifier 2005-NM-048-AD; 
Amendment 39-14070; AD 2005-09-02]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

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

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD) that applies to all Boeing Model 747 series airplanes. The 
existing AD currently requires repetitive inspections for cracking of 
the top and side panel webs and panel stiffeners of the nose wheel well 
(NWW), and corrective actions if necessary. This new AD expands the 
area of inspection, adds a

[[Page 21142]]

new ``secondary'' inspection if certain cracking is found, and reduces 
the intervals for the repetitive inspections. This AD is prompted by a 
report of an in-flight decompression of a Model 747-100 series airplane 
that had accumulated 27,241 total flight cycles. We are issuing this AD 
to detect and correct fatigue cracks in the top and side panel webs and 
stiffeners of the NWW, which could compromise the structural integrity 
of the NWW and could lead to the rapid decompression of the airplane.

DATES: Effective May 10, 2005.
    The incorporation by reference of Boeing Alert Service Bulletin 
747-53A2465, Revision 4, dated February 24, 2005, as listed in the AD, 
is approved by the Director of the Federal Register as of May 10, 2005.
    On January 27, 2005 (69 FR 76839, December 23, 2004), the Director 
of the Federal Register approved the incorporation by reference of 
Boeing Service Bulletin 747-53A2465, Revision 1, dated October 16, 
2003; and Boeing Alert Service Bulletin 747-53A2465, Revision 2, dated 
November 11, 2004.
    We must receive any comments on this AD by June 24, 2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this AD.
    <bullet> DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
    <bullet> Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
    <bullet> Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
    <bullet> Fax: (202) 493-2251.
    <bullet> Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, 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.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street, SW., room PL-
401, on the plaza level of the Nassif Building, Washington, DC. This 
docket number is FAA-2005-21027; the directorate identifier for this 
docket is 2005-NM-048-AD.

Examining the Docket

    You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the DMS receives them.

FOR FURTHER INFORMATION CONTACT: Nick Kusz, Airframe Branch, ANM-120S, 
FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056; telephone (425) 917-6432; fax (425) 917-
6590.

SUPPLEMENTARY INFORMATION: On December 7, 2004, we issued AD 2004-25-
23, amendment 39-13911 (69 FR 76839, December 23, 2004). That AD 
applies to all Boeing Model 747 series airplanes. That AD requires 
repetitive inspections for cracking of the top and side panel webs and 
panel stiffeners of the nose wheel well (NWW), and corrective actions 
if necessary. That AD was prompted by reports indicating that cracks 
have been found on the top and side panel webs and side panel 
horizontal stiffeners of the NWW on Boeing Model 747 series airplanes. 
Investigation revealed that the cracking was due to fatigue. The 
actions specified in that AD are intended to detect and correct fatigue 
cracks in the top and side panel webs and stiffeners of the NWW, which 
could compromise the structural integrity of the NWW and could lead to 
the rapid decompression of the airplane.

Actions Since AD Was Issued

    Since we issued that AD, the FAA has received a report of an in-
flight decompression on a Boeing Model 747-100 series airplane. The 
airplane landed safely, and investigation revealed that the right-hand 
side panel web of the NWW was torn open between station (STA) 260 and 
STA 280, and from water line (WL) 160 to WL 170. The decompression also 
caused damage to the nose landing gear doors and adjacent structure.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin (ASB) 747-53A2465, 
Revision 4, dated February 24, 2005. The ASB describes procedures for 
performing repetitive external detailed and ultrasonic inspections for 
cracking of the top and side panel webs (Areas 1 and 2) of the NWW and 
for performing repetitive internal detailed and surface high frequency 
eddy current inspections (Area 3) for cracking of the top and side 
panel stiffeners of the NWW; replacing cracked stiffeners with new 
stiffeners; and repairing any cracked panel web. Revision 4 of the ASB 
also describes detailed ``secondary inspections'' for certain cracking 
found and specifies contacting Boeing for further action if other 
cracking is found. Revision 4 of the ASB describes procedures for 
expanding the area of inspection of the web from STA 260 to STA 270 
along WL 140. Revision 4 of the ASB also specifies reducing the 
repetitive inspection intervals for Area 1 and Area 2 and includes 
additional repetitive detailed and ultrasonic (UT) inspections. 
Revision 4 of the ASB also describes reducing the repetitive inspection 
intervals for the inspections of Area 3.

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. This AD is being 
issued to supersede AD 2004-25-23. This new AD continues to require 
repetitive inspections for cracking of the top and side panel webs and 
panel stiffeners of the NWW, and corrective actions if necessary. This 
AD expands the area of inspection, adds a new ``secondary'' inspection 
if certain cracking is found, and reduces the repetitive inspection 
intervals.

Differences Between the AD and Revision 4 of the ASB

    Although the ASB specifies that operators may contact the 
manufacturer for disposition of certain repair conditions, this AD 
requires operators to repair those conditions according to a method 
approved by the FAA. Although the ASB specifies certain initial 
inspection compliance times relative to January 27, 2005 (the effective 
date of AD 2004-25-23), this AD requires those certain initial 
inspection compliance times in relation to the effective date of this 
AD. While the ASB describes reducing the current repetitive inspection 
intervals for Area 3 from 6,000 flight cycles to 1,500 flight cycles, 
this AD does not require the reduced intervals. Requiring the 
repetitive intervals at 1,500 flight cycles would allow adequate time 
for public opportunity to comment, and we would issue a proposed AD to 
provide that comment period. Therefore, we may consider further 
rulemaking to address this issue. In addition, the ASB specifies that 
operators should report inspection results to the manufacturer, but 
this AD does not require those inspection results to be reported.

[[Page 21143]]

Change to Existing AD

    This AD would retain certain requirements of AD 2004-25-23. Since 
AD 2004-25-23 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 AD, as listed in the 
following table:

                      Revised Paragraph Identifiers
------------------------------------------------------------------------
                                           Corresponding  requirement in
      Requirement in  AD 2004-25-23                   this AD
------------------------------------------------------------------------
Paragraph (a)............................  Paragraph (f).
------------------------------------------------------------------------

Interim Action

    This is considered to be interim action. As previously discussed, 
we may consider further rulemaking regarding reducing certain 
repetitive inspection intervals. In addition, the manufacturer has 
advised that it currently is developing a modification that will 
address the unsafe condition addressed by this AD. Once this 
modification is developed, approved, and available, the FAA may 
consider additional rulemaking.

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 under ADDRESSES. Include ``Docket No. FAA-2005-21027; 
Directorate Identifier 2005-NM-048-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the AD. We will consider 
all comments received by the closing date and may amend the AD in light 
of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this AD. Using the search function of our docket 
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 can review the DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (65 FR 19477-78), or you can visit 
http://dms.dot.gov.

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. 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 FAA amends Sec.  39.13 by removing amendment 39-13911 (69 FR 
76839, December 23, 2004), and adding the following new airworthiness 
directive (AD):

2005-09-02 Boeing: Docket No. FAA-2005-21027; Directorate Identifier 
2005-NM-048-AD; Amendment 39-14070.

Effective Date

    (a) This AD becomes effective May 10, 2005.

Affected ADs

    (b) This AD supersedes AD 2004-25-23, amendment 39-13911 (69 FR 
76839, December 23, 2004).

Applicability

    (c) This AD applies to all Boeing Model 747 series airplanes, 
certificated in any category.

Unsafe Condition

    (d) This AD was prompted by a report of an in-flight 
decompression of a Model 747-100 series airplane that had 
accumulated 27,241 total flight cycles. We are issuing this AD to 
detect and correct fatigue cracks in the top and side panel webs and 
stiffeners of the Nose Wheel Well (NWW), which could compromise the 
structural integrity of the NWW and could lead to the rapid 
decompression 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.

Restatement of Certain Requirements of AD 2004-25-23

Initial and Repetitive Inspections

    (f) Prior to the accumulation of 16,000 total flight cycles, or 
within 1,000 flight cycles after January 27, 2005 (the effective 
date of AD 2004-25-23), whichever is later, do the inspections 
specified in either paragraph (f)(1) or (f)(2) of this AD.
    (1) Do the inspections specified in paragraphs (f)(1)(i) and 
(f)(1)(ii) of this AD in accordance with the Accomplishment 
Instructions of Boeing Service Bulletin 747-53A2465, Revision 1, 
dated October 16, 2003. Repeat the inspections thereafter at 
intervals not to exceed 1,000 flight cycles.

[[Page 21144]]

    (i) Do detailed and ultrasonic inspections of the top and side 
panel webs of the NWW for cracks.
    (ii) Do detailed and surface high frequency eddy current (HFEC) 
inspections of the top and side panel stiffeners of the NWW for 
cracks.
    (2) Do the inspections specified in paragraphs (f)(2)(i) and 
(f)(2)(ii) of this AD in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2465, Revision 
2, dated November 11, 2004. Repeat the inspections thereafter at the 
intervals specified in paragraphs (f)(2)(i) and (f)(2)(ii) of this 
AD.
    (i) Do external detailed inspections of the top and side panel 
webs of the NWW (specified as Area 1 and Area 2 in the service 
bulletin), as applicable, for cracks. Repeat the inspections 
thereafter at intervals not to exceed 1,000 flight cycles.
    (ii) Do internal detailed and surface HFEC inspections of the 
top and side panel stiffeners of the NWW (specified as Area 3 in the 
service bulletin) for cracks. Repeat the inspections thereafter at 
intervals not to exceed 6,000 flight cycles.

    Note 1: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as 
mirrors, magnifying lenses, etc., may be used. Surface cleaning and 
elaborate access procedures may be required.''

New Requirements of This AD

    (g) Do an external detailed inspection of the top and sidewall 
panel webs of the NWW (specified as Area 1 and Area 2 in the service 
bulletin) for cracks, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin (ASB) 747-53A2465, 
Revision 4, dated February 24, 2005, at the earlier of the times 
specified in paragraphs (g)(1) and (g)(2) of this AD. Accomplishment 
of this inspection terminates the requirements for the inspections 
specified in paragraphs (f)(1)(i) and (f)(2)(i) of this AD.
    (1) At the later of the times specified in paragraph (g)(1)(i) 
and (g)(1)(ii) of this AD:
    (i) Before accumulating 20,000 total flight cycles.
    (ii) Within 100 flight cycles or 90 days after the effective 
date of this AD, whichever occurs first.
    (2) At the later of the times specified in paragraphs (g)(2)(i) 
and (g)(2)(ii) of this AD:
    (i) Before accumulating 16,000 total flight cycles.
    (ii) Within 1,000 flight cycles after the effective date of this 
AD.

Repetitive Inspections

    (h) Repeat the inspection required by paragraph (g) of this AD 
at the intervals specified in paragraph (h)(1) or (h)(2) of this AD, 
as applicable.
    (1) For airplanes with less than 20,000 total flight cycles as 
of the effective date of this AD, repeat at intervals not to exceed 
1,000 flight cycles until the first inspection after the airplane 
reaches 20,000 total flight cycles.
    (2) For airplanes with 20,000 total flight cycles or more, 
repeat at intervals not to exceed 500 flight cycles.

Ultrasonic Inspections (UT)

    (i) Do a UT inspection of the sidewall panel web for cracks, in 
accordance with Boeing ASB 747-53A2465, Revision 4, dated February 
24, 2005, at the later of the times specified in paragraphs (i)(1) 
and (i)(2) of this AD. Repeat the inspections thereafter at 
intervals not to exceed 500 flight cycles.
    (1) Prior to the accumulation of 20,000 total flight cycles.
    (2) Within 100 flight cycles or within 90 days after the 
effective date of this AD, whichever occurs first.

Additional Inspections and Corrective Actions

    (j) Except as specified in paragraph (l) of this AD, if any 
crack is found during any inspection required by this AD, prior to 
further flight, do any applicable additional detailed inspections of 
stiffeners and beams and make repairs, in accordance with the 
Accomplishment Instructions of Boeing ASB 747-53A2465, Revision 4, 
dated February 24, 2005.

Actions Accomplished per Previous Issues of Service Bulletin

    (k) Inspections and corrective actions accomplished before 
January 27, 2005, in accordance with Boeing ASB 747-53A2465, dated 
April 5, 2001, are considered acceptable for compliance with the 
corresponding inspections specified in paragraph (f) of this AD. 
Inspections and corrective actions accomplished before the effective 
date of this AD, in accordance with Boeing Service Bulletin 747-
53A2465, Revision 1, dated October 16, 2003; Revision 2, dated 
November 11, 2004; and Revision 3, dated December 23, 2004; are 
considered acceptable for compliance with the corresponding 
inspections specified in paragraphs (g) and (h) of this AD.

Certain Other Corrective Actions

    (l) Where the ASB specifies contacting the manufacturer if 
certain cracking is found, this AD requires repairing the cracking 
according to a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA, or by an Authorized Representative 
for the Boeing Delegation Option Authorization Organization who has 
been authorized by the Manager, Seattle ACO, to make those findings. 
The repair must be accomplished before further flight. For a repair 
method to be approved by the Manager, Seattle ACO, as required by 
this paragraph, the Manager's approval letter must specifically 
refer to this AD.

No Reporting Requirements

    (m) Although the Boeing ASB specifies that operators should 
report inspection results to the manufacturer, this AD does not 
require those inspection results to be reported.

Alternative Methods of Compliance (AMOCs)

    (n)(1) The Manager, Seattle 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) 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 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

    (o) You must use Boeing Service Bulletin 747-53A2465, Revision 
1, dated October 16, 2003; Boeing Alert Service Bulletin 747-
53A2465, Revision 2, dated November 11, 2004; and Boeing Alert 
Service Bulletin 747-53A2465, Revision 4, dated February 24, 2005; 
as applicable, to perform the actions that are required by this AD, 
unless the AD specifies otherwise.
    (1) The incorporation by reference of Boeing Alert Service 
Bulletin 747-53A2465, Revision 4, dated February 24, 2005, is 
approved by the Director of the Federal Register in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51.
    (2) The incorporation by reference of Boeing Service Bulletin 
747-53A2465, Revision 1, dated October 16, 2003; and Boeing Alert 
Service Bulletin 747-53A2465, Revision 2, dated November 11, 2004; 
was approved previously by the Director of the Federal Register as 
of January 27, 2005 (69 FR 76839, December 23, 2004).
    (3) To get copies of the service information, contact Boeing 
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. 
To view the AD docket, go to the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street SW., room PL-401, 
Nassif Building, Washington, DC. To review copies of the service 
information, go to the National Archives and Records Administration 
(NARA). For information on the availability of this material at the 
NARA, call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

    Issued in Renton, Washington, on April 13, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-8098 Filed 4-22-05; 8:45 am]
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