[Federal Register Volume 72, Number 153 (Thursday, August 9, 2007)]
[Rules and Regulations]
[Pages 44728-44731]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-15416]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28015; Directorate Identifier 2006-NM-210-AD; 
Amendment 39-15147; AD 2007-16-08]
RIN 2120-AA64


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

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

ACTION: Final rule.

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SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD), which applies to all Boeing Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, and 747SR series 
airplanes. That AD currently requires repetitive inspections for 
cracking of the station 800 frame assembly, and repair if necessary. 
This new AD revises certain applicabilities and compliance times in the 
existing AD. This AD results from several reports of cracks of the 
station 800 frame assembly on airplanes that had accumulated fewer 
total flight cycles than the initial inspection threshold in the 
original AD. We are issuing this AD to detect and correct fatigue 
cracks that could extend and fully sever the frame, which could result 
in development of skin cracks that could lead to rapid depressurization 
of the airplane.

DATES: This AD becomes effective September 13, 2007.
    On July 17, 2006 (71 FR 33595, June 12, 2006), the Director of the 
Federal Register approved the incorporation by reference of Boeing 
Alert Service Bulletin 747-53A2451, Revision 1, dated November 10, 
2005.
    On August 30, 2001 (66 FR 38891, July 26, 2001), the Director of 
the Federal Register approved the incorporation by reference of Boeing 
Alert Service Bulletin 747-53A2451, including Appendix A, dated October 
5, 2000.

ADDRESSES: You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue, SE., Washington, DC.
    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 98057-3356; telephone (425) 917-6437; 
fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: 

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 floor of the 
West Building at the DOT street address stated in the ADDRESSES 
section.

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that supersedes AD 2006-12-12, amendment 
39-14638 (71 FR 33595, June 12, 2006). The existing AD applies to all 
Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-
300, 747-400, 747-400D, and 747SR series airplanes. That NPRM was 
published in the Federal Register on April 26, 2007 (72 FR 20782). That 
NPRM proposed to continue to require repetitive inspections for 
cracking of the station 800 frame assembly, and repair if necessary. 
That NPRM also proposed to revise certain applicabilities and 
compliance times in the existing AD.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the single comment that has 
been received on the NPRM. The commenter, Boeing, supports the NPRM.

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.

Conclusion

    We have carefully reviewed the available data, including the 
comment that has been received, and determined that air safety and the 
public interest require adopting the AD with the change described 
previously. We have determined that this change will neither increase 
the economic burden on any

[[Page 44729]]

operator nor increase the scope of the AD.

Costs of Compliance

    There are about 900 airplanes of the affected design in the 
worldwide fleet. This AD affects about 156 airplanes of U.S. registry.
    The repetitive inspections take between 12 and 14 work hours per 
airplane, depending on the airplane configuration. The average labor 
rate is $80 per work hour. Based on these figures, the estimated cost 
of the currently required actions is between $149,760 and $174,720, or 
between $960 and $1,120 per airplane, per inspection cycle.
    The repetitive inspections of the expanded area take between 18 and 
20 work hours per airplane, at an average labor rate of $80 per work 
hour. Based on these figures, the estimated cost of the new actions 
specified in this AD for U.S. operators is between $224,640 and 
$249,600, or between $1,440 and $1,600 per airplane, per inspection 
cycle.

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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under 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 
removing amendment 39-14638 (71 FR 33595, June 12, 2006) and by adding 
the following new airworthiness directive (AD):

2007-16-08 Boeing: Amendment 39-15147. Docket No. FAA-2007-28015; 
Directorate Identifier 2006-NM-210-AD.

Effective Date

    (a) This AD becomes effective September 13, 2007.

Affected ADs

    (b) This AD supersedes AD 2006-12-12.

Applicability

    (c) This AD applies to all Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, and 747SR 
series airplanes, certificated in any category.

Unsafe Condition

    (d) This AD results from several reports of cracks of the 
station 800 frame assembly on airplanes that had accumulated fewer 
total flight cycles than the initial inspection threshold in the 
original AD. We are issuing this AD to detect and correct fatigue 
cracks that could extend and fully sever the frame, which could 
result in development of skin cracks that could lead to rapid 
depressurization 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 2006-12-12 With Revised Appicabilities and 
Thresholds

Repetitive Inspections

    (f) For Boeing Model 747-100, 747-100B, 747-200B, 747-200C, and 
747SR series airplanes, as identified in Boeing Alert Service 
Bulletin 747-53A2451, including Appendix A, dated October 5, 2000: 
Do detailed, surface high-frequency eddy current (HFEC), and open-
hole HFEC inspections, as applicable, for cracking of the station 
800 frame assembly (including the inner chord strap, angles, and 
exposed web) between stringers 14 and 18, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2451, including Appendix A, dated October 5, 2000; or Boeing 
Alert Service Bulletin 747-53A2451, Revision 1, dated November 10, 
2005; after the effective date of this AD, only Revision 1 of the 
service bulletin may be used. Except as provided by paragraph (g) of 
this AD, do the inspection at the applicable time specified in Table 
1 or Table 2 of this AD, as applicable, and repeat the inspections 
thereafter at intervals not to exceed 3,000 flight cycles until the 
initial inspections required by paragraph (h) of this AD are 
accomplished.

Table 1.--Compliance Times for Boeing Model 747-100, 747-100B, 747-200B,
                      and 747-200C Series Airplanes
------------------------------------------------------------------------
  Total flight cycles as of August 30,
2001  (the effective date of AD 2001-14-  Do the inspection in paragraph
   22, amendment 39-12333,  which was      (f) of this AD at this time
      superseded by AD 2006-12-12)
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(1) Fewer than 19,000..................  Before the accumulation of
                                          19,000 total flight cycles, or
                                          within 1,500 flight cycles
                                          after August 30, 2001,
                                          whichever comes later.
(2) 19,000 or more, but 24,250 or fewer  Within 1,500 flight cycles or
                                          12 months after August 30,
                                          2001, whichever comes first.

[[Page 44730]]

 
(3) 24,251 or more.....................  Within 750 flight cycles or 12
                                          months after August 30, 2001,
                                          whichever comes first.
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   Table 2.--Compliance Times for Boeing Model 747SR Series Airplanes
------------------------------------------------------------------------
Total flight cycles as of the effective   Do the inspection in paragraph
            date of this AD                (f) of this AD at this time
------------------------------------------------------------------------
(4) Fewer than 19,000..................  Before the accumulation of
                                          19,000 total flight cycles, or
                                          within 1,500 flight cycles
                                          after the effective date of
                                          this AD, whichever comes
                                          later.
(5) 19,000 or more, but 24,250 or fewer  Within 1,500 flight cycles or
                                          12 months after the effective
                                          date of this AD, whichever
                                          comes first.
(6) 24,251 or more.....................  Within 750 flight cycles or 12
                                          months after the effective
                                          date of this AD, whichever
                                          comes first.
------------------------------------------------------------------------

Adjustments to Compliance Time: Cabin Differential Pressure

    (g) For Boeing Model 747-100, 747-100B, 747-200B, and 747-200C 
series airplanes, as identified in Boeing Alert Service Bulletin 
747-53A2451, including Appendix A, dated October 5, 2000, that were 
inspected before July 17, 2006 (the effective date of AD 2006-12-
12); and for Boeing Model 747SR airplanes, as identified in Boeing 
Alert Service Bulletin 747-53A2451, that were inspected before the 
effective date of this AD: Except as provided by paragraph (i) of 
this AD, for the purposes of calculating the compliance threshold 
and repetitive interval for the actions required by paragraph (f) of 
this AD, the number of flight cycles in which cabin differential 
pressure is at 2.0 pounds per square inch (psi) or less need not be 
counted when determining the number of flight cycles that have 
occurred on the airplane, provided that the flight cycles with 
momentary spikes in cabin differential pressure above 2.0 psi are 
included as full pressure cycles. For this provision to apply, all 
cabin pressure records must be maintained for each airplane: No 
fleet-averaging of cabin pressure is allowed.

Repetitive Inspections of Expanded Area at a New Reduced Threshold

    (h) For all airplanes, at the applicable time specified in Table 
3 of this AD, except as provided by paragraph (i) of this AD, do the 
following inspections of the station 800 frame assembly in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-53A2451, Revision 1, dated November 10, 2005: A 
detailed inspection for cracking of the inner chord strap, angles, 
and exposed web adjacent to the inner chords on the station 800 
frame between stringer 14 and stringer 18; and surface HFEC and 
open-hole HFEC inspections for cracking of the inner chord strap and 
angles. Do the initial inspections at the applicable time specified 
in Table 3 of this AD, and repeat the inspections thereafter at 
intervals not to exceed 3,000 flight cycles. Accomplishing the 
initial inspections required by this paragraph terminates the 
inspection requirements of paragraph (f) of this AD.

                   Table 3.--Revised Compliance Times
------------------------------------------------------------------------
   Total flight cycles as of July 17,    Do the inspections in paragraph
                 2006--                   (h) of this AD at this time--
------------------------------------------------------------------------
(1) Fewer than 16,000..................  Before the accumulation of
                                          16,000 total flight cycles, or
                                          within 1,500 flight cycles
                                          after July 17, 2006, whichever
                                          comes later.
(2) 16,000 or more, but 21,250 or fewer  Within 1,500 flight cycles
                                          after July 17, 2006, or within
                                          1,000 flight cycles after the
                                          effective date of this AD,
                                          whichever comes later.
(3) 21,251 or more.....................  Within 750 flight cycles after
                                          July 17, 2006, or within 500
                                          flight cycles after the
                                          effective date of this AD,
                                          whichever comes later.
------------------------------------------------------------------------

Adjustments to Compliance Time: Cabin Differential Pressure

    (i) For the purposes of calculating the compliance threshold and 
repetitive interval for actions required by paragraphs (f) and (h) 
of this AD, for Boeing Model 747-100, 747-100B, 747-200B, and 747-
200C series airplanes, on or after July 17, 2006; and for Boeing 
Model 747SR series airplanes, on or after the effective date of this 
AD: All flight cycles, including the number of flight cycles in 
which cabin differential pressure is at 2.0 psi or less, must be 
counted when determining the number of flight cycles that have 
occurred on the airplane. However, for airplanes on which the 
repetitive interval for the actions required by paragraph (f) of 
this AD have been calculated in accordance with paragraph (g) of 
this AD by excluding the number of flight cycles in which cabin 
differential pressure is at 2.0 pounds psi or less: Continue to 
adjust the repetitive inspection interval in accordance with 
paragraph (g) of this AD until the initial inspections required by 
paragraph (h) of this AD are accomplished. Thereafter, no adjustment 
to compliance times based on paragraph (g) of this AD is allowed.

Repair

    (j) If any cracking is detected during any inspection required 
by paragraph (f) or (h) of this AD, and the service bulletin 
specifies to contact Boeing for appropriate action: Before further 
flight, repair using a method approved in accordance with the 
procedures specified in paragraph (l) of this AD.

No Report Required

    (k) Although the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-53A2451, including Appendix A, dated October 5, 
2000; and Boeing Alert Service Bulletin 747-53A2451, Revision 1, 
dated November 10, 2005; describe procedures for reporting certain 
information to the manufacturer, this AD does not require that 
report.

Alternative Methods of Compliance (AMOCs)

    (l)(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.

[[Page 44731]]

    (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.
    (4) AMOCs approved previously in accordance with AD 2001-14-22, 
are approved as AMOCs for the corresponding provisions of paragraphs 
(f) and (j) of this AD.
    (5) AMOCS approved previously in accordance with AD 2006-12-12, 
are approved as alternative methods of compliance with this AD.

Material Incorporated by Reference

    (m) You must use Boeing Alert Service Bulletin 747-53A2451, 
including Appendix A, dated October 5, 2000; or Boeing Alert Service 
Bulletin 747-53A2451, Revision 1, dated November 10, 2005; as 
applicable, to perform the actions that are required by this AD, 
unless the AD specifies otherwise.
    (1) On July 17, 2006 (71 FR 33595, June 12, 2006), the Director 
of the Federal Register approved the incorporation by reference of 
Boeing Alert Service Bulletin 747-53A2451, Revision 1, dated 
November 10, 2005.
    (2) On August 30, 2001 (66 FR 38891, July 26, 2001), the 
Director of the Federal Register approved the incorporation by 
reference of Boeing Alert Service Bulletin 747-53A2451, including 
Appendix A, dated October 5, 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 July 30, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-15416 Filed 8-8-07; 8:45 am]
BILLING CODE 4910-13-P