[Federal Register Volume 72, Number 95 (Thursday, May 17, 2007)]
[Rules and Regulations]
[Pages 27723-27725]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-9396]



[[Page 27723]]

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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-22288; Directorate Identifier 2005-NM-132-AD; 
Amendment 39-15050; AD 2007-10-09]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-400 Series Airplanes

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

ACTION: Final rule; request for comments.

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

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Boeing Model 747-400 series airplanes. This AD requires 
repetitive inspections for any crack in the upper deck floor beam at 
station 400, which include inspecting the floor beam web and chords, 
certain fastener holes at the intersection of the floor beam and frame 
on both sides of the airplane, and certain floor panel attachment 
fastener holes at the floor beam upper chords. This AD also requires 
corrective action if necessary. This AD results from several reports 
indicating that fatigue cracking was found in upper deck floor beams 
made from 7000 series aluminum alloy. We are issuing this AD to detect 
and correct cracking in the upper deck floor beam at station 400, which 
could extend and sever the floor beam. A severed floor beam could 
result in loss of controllability and rapid decompression of the 
airplane.

DATES: This AD becomes effective June 1, 2007.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of June 1, 2007.
    We must receive comments on this AD by July 16, 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: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     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.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT: Ivan Li, Aerospace Engineer, Airframe 
Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind 
Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6437; 
fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that would apply to certain Boeing Model 
747-400 series airplanes. That NPRM was published in the Federal 
Register on September 6, 2005 (70 FR 52943). That NPRM proposed to 
require doing a conductivity test of the upper deck floor beam at 
station 400 to identify the floor beam material. If the floor beam is 
manufactured from 7050 aluminum alloy, that NPRM also proposed to 
require inspecting the upper deck floor beam and certain fastener holes 
at the floor beam upper chord for cracking; repairing any cracking if 
necessary; and doing a preventative modification.

Actions Since NPRM Was Issued

    Since we issued the NPRM, Boeing has published Alert Service 
Bulletin 747-53A2660, dated November 16, 2006, to replace Boeing Alert 
Service Bulletin 747-53A2509, dated June 9, 2005. In the NPRM, we 
referred to Boeing Alert Service Bulletin 747-53A2509 as the 
appropriate source of service information for accomplishing the 
proposed conductivity test, one-time inspections of the upper deck 
floor beam and certain fastener holes for cracking and repair if 
necessary, reporting requirement, and preventative modification. We 
proposed the conductivity test and reporting requirement to find the 
two upper deck floor beams that were made from 7050-T7451 aluminum 
alloy, which are more susceptible to fatigue cracking. After several 
operators accomplished the conductivity test specified in Boeing Alert 
Service Bulletin 747-53A2509, the discrepant upper deck floor beams 
were found on two airplanes at station 400. Therefore, we have revised 
the applicability in paragraph (c) of this AD to include only those 
affected airplanes. Since the proposed conductivity test and reporting 
requirement, which were specified in paragraphs (f) and (f)(2) of the 
NPRM respectively, are no longer required, we have deleted those 
actions from this AD. Further, we have also deleted the preventative 
modification, which was specified in paragraph (f)(3) of the NPRM. This 
AD instead requires accomplishing new repetitive inspections, which are 
specified in paragraphs (f)(1), (f)(2), and (f)(3) of this AD. We have 
determined that the new repetitive inspections are sufficient to 
maintain an acceptable level of safety. We have described the new 
repetitive inspections under ``Relevant Service Information.''

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-53A2660, dated 
November 16, 2006. Part 1 of the Accomplishment Instructions of the 
service bulletin describes procedures for doing (1) repetitive detailed 
inspections for any crack in the upper deck floor beam at the 
intersection of the floor beam and frame on both sides of the airplane, 
(2) repetitive open hole high frequency eddy current (HFEC) inspections 
for any crack in certain fastener holes at the intersection of the 
floor beam upper chord and the frame inner chord on both sides of the 
airplane, and (3) corrective actions if necessary. The corrective 
actions include (1) contacting Boeing for repair instructions if any 
crack is found in the floor beam during any detailed inspection, (2) 
oversizing the cracked fastener holes at the intersection of the floor 
beam upper chord and frame inner chord, and doing open hole HFEC 
inspections of the oversized faster holes, if any crack is found in the 
fastener holes during any HFEC inspection, (3) installing an oversized 
fastener, if no crack is found in an oversized fastener hole and a 
minimum edge margin of 1.7D is maintained, and (4) contacting Boeing 
for repair instructions if any crack in a fastener hole cannot not be 
removed by oversizing the fastener hole and maintaining a minimum edge 
margin of 1.7D.
    Part 2 of the Accomplishment Instructions of the service bulletin 
describes procedures for doing repetitive open hole HFEC inspections 
for any crack in the upper deck floor beam at all floor panel 
attachment fastener holes through the forward and aft horizontal 
flanges of the floor beam upper chord, from the left body frame to the 
right body frame; and doing corrective actions if necessary. The 
corrective action includes contacting Boeing for repair instructions if 
any crack is found at the floor panel attachment fastener holes.

[[Page 27724]]

    The service bulletin specifies accomplishing the initial 
inspections in Parts 1 and 2 of the Accomplishment Instructions before 
the airplane has accumulated 18,000 total flight cycles. The service 
bulletin also specifies a repetitive interval of 10,000 flight cycles 
for the inspections in Part 1 of the Accomplishment Instructions and a 
repetitive interval of 6,000 flight cycles for the inspection in Part 2 
of the Accomplishment Instructions.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Request To Clarify the Source of Reported Cracking

    Boeing requests that we clarify that this AD results from several 
reports of fatigue cracking found in upper deck floor beams made from 
7000 series aluminum alloy, not 7050 aluminum alloy. Boeing states that 
7050 aluminum alloy was not yet an option when cracking was found in 
the upper deck floor beams on Model 747 airplanes; cracking was found 
on airplanes with 7075-T6 upper deck floor beams, which prompted 
issuance of other related rulemaking (as identified in the NPRM) to 
address that unsafe condition. The commenter also states that the 
fatigue and crack growth in the 7050 beams is expected to be marginally 
better than in the 7075 beams.
    We agree with Boeing's request and have revised the ``Summary'' and 
paragraph (d) of this AD.

Clarification of Alternative Method of Compliance (AMOC) Paragraph

    We have revised this action to clarify the appropriate procedure 
for notifying the principal inspector before using any approved AMOC on 
any airplane to which the AMOC applies.

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 that may be 
registered in the U.S. at some time in the future. Therefore, we are 
issuing this AD to detect and correct cracking in the upper deck floor 
beam, which could extend and sever the floor beam. A severed floor beam 
could result in loss of controllability and rapid decompression of the 
airplane. This AD requires accomplishing the actions specified in the 
service information described previously.

Explanation of Changes to Costs of Compliance

    In the NPRM, we estimated that there are about 123 airplanes of the 
affected design in the worldwide fleet and about 17 airplanes of U.S. 
registry. However, since issuance of the NPRM, we have determined that 
only 2 airplanes are affected by this AD. Those affected airplanes are 
currently operated by non-U.S. operators under foreign registry. 
Therefore, we have revised the ``Costs of Compliance'' accordingly.
    After the NPRM was issued, we reviewed the figures we have used 
over the past several years to calculate AD costs to operators. To 
account for various inflationary costs in the airline industry, we find 
it necessary to increase the labor rate used in these calculations from 
$65 per work hour to $80 per work hour. The cost impact information, 
below, reflects this increase in the specified hourly labor rate.

Costs of Compliance

    If an affected airplane is imported and placed on the U.S. Register 
in the future, the required inspections would take about 5 work hours, 
at an average labor rate of $80 per work hour. Based on these figures, 
we estimate the cost of this AD to be $400 per airplane, per inspection 
cycle.

FAA's Determination of the Effective Date

    No airplane affected by this AD is currently on the U.S. Register. 
Therefore, providing notice and opportunity for public comment is 
unnecessary before this AD is issued, and this AD may be made effective 
in less than 30 days after it is published in the Federal Register.

Comments Invited

    This AD is a final rule that involves requirements that affect 
flight safety. The new requirements, which are to be done in accordance 
with Boeing Alert Service Bulletin 747-53A2660, dated November 16, 
2006, were 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 the ADDRESSES section. Include ``Docket No. FAA-2005-
22288; Directorate Identifier 2005-NM-132-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 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 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 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

[[Page 27725]]

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 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 
adding the following new airworthiness directive (AD):

2007-10-09 Boeing: Amendment 39-15050. Docket No. FAA-2005-22288; 
Directorate Identifier 2005-NM-132-AD.

Effective Date

    (a) This AD becomes effective June 1, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 747-400 series airplanes, 
certificated in any category; as identified in Boeing Alert Service 
Bulletin 747-53A2660, dated November 16, 2006.

Unsafe Condition

    (d) This AD results from several reports indicating that fatigue 
cracking was found in upper deck floor beams made from 7000 series 
aluminum alloy. We are issuing this AD to detect and correct 
cracking in the upper deck floor beam at station 400, which could 
extend and sever the floor beam. A severed floor beam could result 
in loss of controllability and 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.

Repetitive Inspections and Corrective Actions

    (f) At the applicable times specified in Table 1 of paragraph 
1.E. of Boeing Alert Service Bulletin 747-53A2660, dated November 
16, 2006, do the actions specified in paragraphs (f)(1), (f)(2), and 
(f)(3) of this AD and do all applicable corrective actions, by 
accomplishing all the applicable actions specified in the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2660, dated November 16, 2006; except where the service bulletin 
specifies to contact Boeing for appropriate action: Before further 
flight, repair the crack using a method approved in accordance with 
paragraph (g) of this AD. Do all applicable corrective actions 
before further flight.
    (1) Repetitive detailed inspections for any crack in the upper 
deck floor beam at the intersection of the floor beam and frame on 
both sides of the airplane.
    (2) Repetitive open hole high frequency eddy current (HFEC) 
inspections for any crack in certain fastener holes at the 
intersection of the floor beam upper chord and the frame inner chord 
on both sides of the airplane.
    (3) Repetitive open hole HFEC inspections for any crack in the 
upper deck floor beam at all floor panel attachment fastener holes 
through the forward and aft horizontal flanges of the floor beam 
upper chord, from the left body frame to the right body frame.

Alternative Methods of Compliance (AMOCs)

    (g)(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

    (h) You must use Boeing Alert Service Bulletin 747-53A2660, 
dated November 16, 2006, to perform the actions that are required by 
this AD, unless the AD specifies otherwise. The Director of the 
Federal Register approved the incorporation by reference of this 
document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 
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, S.W., 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 May 7, 2007.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-9396 Filed 5-16-07; 8:45 am]
BILLING CODE 4910-13-P