[Federal Register Volume 70, Number 53 (Monday, March 21, 2005)]
[Rules and Regulations]
[Pages 13353-13356]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-5386]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19495; Directorate Identifier 2003-NM-180-AD; 
Amendment 39-14019; AD 2005-06-11]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100, -100B, -100B SUD, 
-200B, and -300 Series Airplanes; and Model 747SR and 747SP 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 certain Boeing Model 747-100, -100B, -100B SUD, 
-200B, and -300 series airplanes; and Model 747SR and 747SP series 
airplanes. That AD currently requires repetitive inspections to detect 
fatigue cracking in the upper deck floor beams located at certain body 
stations, and repair, if necessary. This new AD lowers the threshold 
for the existing inspections and requires new repetitive inspections of 
previously repaired areas, and repair if necessary. This AD is prompted 
by the results of an additional detailed analysis that indicate fatigue 
cracks can initiate sooner than has previously been observed. We are 
issuing this AD to prevent failure of the upper deck floor beams at 
certain body stations due to fatigue cracking, which could result in 
rapid decompression and reduced controllability of the airplane.

DATES: This AD becomes effective April 25, 2005.

[[Page 13354]]

    The incorporation by reference of a certain publication listed in 
the AD is approved by the Director of the Federal Register as of April 
25, 2005.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
    Docket: The AD docket contains the proposed AD, comments, and any 
final disposition. 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 U.S. 
Department of Transportation, 400 Seventh Street, SW., room PL-401, 
Washington, DC. This docket number is FAA-2004-19495; the directorate 
identifier for this docket is 2003-NM-180-AD.

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

SUPPLEMENTARY INFORMATION: The FAA proposed to amend part 39 of the 
Federal Aviation Regulations (14 CFR Part 39) with an AD to supersede 
AD 2000-04-17, amendment 39-11600 (65 FR 10695, February 29, 2000). The 
existing AD applies to certain Boeing Model 747-100, -100B, -100B SUD, 
-200B, and -300 series airplanes; and Model 747SR and 747SP series 
airplanes. The proposed AD was published in the Federal Register on 
November 3, 2004 (69 FR 63965), to continue to require repetitive 
inspections to detect fatigue cracking in the upper deck floor beams 
located at certain body stations, and repair, if necessary. The action 
also proposed to lower the threshold for the existing repetitive 
inspections. In addition, the action also proposed to require new 
repetitive inspections of previously repaired areas, and repair of any 
crack.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments that have been 
submitted on the proposed AD.

Request To Exclude Counting of Certain Flight Cycles

    One commenter, the airplane manufacturer, requests that paragraph 
(g) of the proposed AD be revised to exclude counting of flight cycles 
with a cabin differential pressure of 2.0 pounds per square inch (psi) 
or less when determining the number of flight cycles to be used to 
determine the inspection compliance threshold and repeat intervals for 
the proposed actions. The commenter notes that this would align with 
the requirements of paragraph (c) of AD 2004-03-11, amendment 39-13455 
(69 FR 5920, February 9, 2004). The commenter states that the fatigue 
and crack growth behavior at the floor panel holes in the upper chord 
of the upper deck floor beams, which are the subject of the proposed 
AD, is caused by tension stresses in the floor beam upper chords. The 
tension stresses in the 747 upper deck floor beams at stations 340, 
360, and 380 are almost entirely the result of reacting load due to 
cabin differential pressure. Thus, the commenter concludes that it is 
technically correct to not count flights, which have a low cabin 
differential pressure and do not significantly contribute to fatigue 
and crack growth.
    We do not agree with the commenter's request. Although we discussed 
the matter of not granting credit for pressurization cycles less than 
2.0 psi in the ``Differences Between the Proposed AD and Service 
Bulletin'' section of the proposed AD, we find that further 
clarification is necessary.
    The commenter correctly notes that the requirements of paragraph 
(c) of AD 2004-03-11 exclude counting pressurization cycles less than 
2.0 psi. We acknowledge the commenter's technical rationale for not 
counting the pressurization cycles less than 2.0 psi in this AD. 
However, we do not agree with the commenter's request for the following 
reasons:
     There have been several instances on other in-service 
issues where analytical rationales, similar to that of the commenter, 
have indicated that pressurization cycles less than 2.0 psi should not 
be counted. However, when fleet records have been examined, the 
airplanes engaging in such operations are having the same or greater 
occurrences of crack findings compared to those on which all 
pressurized flights are counted. As a result, we carefully consider 
such matters based on all available factors, including individual 
operators' specific maintenance programs, technical rationale, and 
fleet experience.
     We have found that such provisions are applicable only to 
a small number of operators that may not pressurize their airplanes 
above 2.0 psi in all their flights. We have determined that the best 
way to handle such circumstances is for operators to request an 
alternative method of compliance (AMOC) in accordance with paragraph 
(n) of this AD, rather than increasing the complexity of the AD by 
addressing each operator's unique situation.

Request To Allow Changing of Inspection Methods

    The same commenter requests that paragraph (h) of the proposed AD 
be revised to allow changing repetitive inspection methods in paragraph 
(h)(1) or (h)(2) of the proposed AD no matter which inspection method 
was used previously, provided that the corresponding repetitive 
inspection interval of 3,000 flight cycles or 750 flight cycles, 
respectively, is imposed. The commenter notes that this is allowed in 
Figure 1 of Boeing Alert Service Bulletin 747-53A2431, Revision 2, 
dated June 13, 2002 (referenced as the appropriate source of service 
information for accomplishing the proposed actions).
    We agree. We have determined that, after accomplishing any 
inspection required by paragraph (h)(1) or (h)(2) of this AD, 
accomplishing any subsequent inspection using the alternate inspection 
method is adequate to detect cracking, provided that its corresponding 
repetitive interval is used. We have revised paragraph (h) of this AD 
accordingly.

Changes to Delegation Authority

    Boeing has received a Delegation Option Authorization (DOA). We 
have revised certain new requirements in this final rule to delegate 
the authority to approve an alternative method of compliance for any 
repair required by this AD to the Authorized Representative for the 
Boeing DOA Organization rather than the Designated Engineering 
Representative. We have also revised certain requirements of AD 2000-
04-17, which are retained in this final rule, to provide this 
delegation authority as an option.

Conclusion

    We have carefully reviewed the available data, including the 
comments that have been submitted, and determined that air safety and 
the public interest require adopting the AD with the changes described 
previously. We have determined that these changes will neither increase 
the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 539 Model 747-100, -100B, -100B SUD, -200B, and -
300 series airplanes; and Model 747SR and

[[Page 13355]]

747SP series airplanes worldwide of the affected design. This AD will 
affect about 168 airplanes of U.S. registry.
    The actions that are currently required by AD 2000-04-17 and 
retained in this AD take about 15 work hours per airplane, at an 
average labor rate of $65 per work hour. Based on these figures, 
estimated cost of the currently required actions is $163,800, or $975 
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. 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 FAA amends Sec.  39.13 by removing amendment 39-11600 (65 FR 
10695, February 29, 2000), and by adding the following new 
airworthiness directive (AD):

2005-06-11 Boeing: Amendment 39-14019. Docket No. FAA-2004-19495; 
Directorate Identifier 2003-NM-180-AD.

Effective Date

    (a) This AD becomes effective April 25, 2005.

Affected ADs

    (b) This AD supersedes AD 2000-04-17, amendment 39-11600 (65 FR 
10695, February 29, 2000).

Applicability

    (c) This AD applies to Boeing Model 747-100, -100B, -100B SUD, -
200B, and -300 series airplanes; and Model 747SR and 747SP series 
airplanes; certificated in any category; as identified in Boeing 
Alert Service Bulletin 747-53A2431, Revision 2, dated June 13, 2002.

Unsafe Condition

    (d) This AD was prompted by the results of an additional 
detailed analysis that indicate fatigue cracks can initiate sooner 
than has previously been observed. We are issuing this AD to prevent 
failure of the upper deck floor beams at certain body stations (BS) 
due to fatigue cracking, which could result in rapid decompression 
and reduced controllability 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.

New Initial Compliance Time

    (f) At the earlier of the times specified in paragraphs (f)(1) 
and (f)(2) of this AD, do the actions specified in paragraph (h) of 
this AD.
    (1) Before the accumulation of 28,000 total flight cycles, or 
within 60 days after March 15, 2000 (the effective date of AD 2000-
04-17, amendment 39-11600), whichever occurs later.
    (2) Before the accumulation of 18,000 total flight cycles, or 
within 1,000 flight cycles after the effective date of this AD, 
whichever occurs later.

Determining Number of Flight Cycles for Compliance Time

    (g) For the purposes of calculating the compliance threshold for 
the actions required by paragraph (f) of this AD, all pressurized 
flight cycles, including the number of flight cycles in which cabin 
differential pressure is at 2.0 pounds per square inch (psi) or 
less, must be counted when determining the number of flight cycles 
that have occurred on the airplane. Where the service bulletin and 
this AD differ, the AD prevails.

Requirements of AD 2000-04-17 and New Repair Method

    (h) At the time specified in paragraph (f) of this AD, perform 
the actions required by either paragraph (h)(1) or (h)(2) of this 
AD. After any inspection, operators may conduct the subsequent 
inspection using the alternate inspection method provided that its 
corresponding repetitive inspection interval is used, rather than 
the interval for the previous inspection method.
    (1) Gain access to the upper deck floor beams from above the 
upper deck floor, and perform an open-hole high frequency eddy 
current (HFEC) inspection to detect cracking of the upper deck floor 
beams at BS 340 and 360, and on both the left and right sides of the 
floor beam at BS 380 between buttock lines (BL) 40 and 76; in 
accordance with Part 1 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-53A2431, Revision 2, dated June 13, 2002.
    (i) If no cracking is found, perform the actions required by 
paragraph (h)(1)(i)(A), (h)(1)(i)(B), or (h)(1)(i)(C) of this AD, in 
accordance with the alert service bulletin.
    (A) Repeat the inspection required by paragraph (h)(1) of this 
AD at intervals not to exceed 3,000 flight cycles.
    (B) Modify (oversize) the floor panel attachment fastener holes 
as specified in Figure 5 of the alert service bulletin, and repeat 
the inspection required by paragraph (h)(1) of this AD within 10,000 
flight cycles. Repeat the inspection at intervals not to exceed 
3,000 flight cycles.
    (C) Do the applicable repair procedures shown in Part 3 of the 
Accomplishment Instructions of the alert service bulletin; except 
where the alert service bulletin specifies to contact Boeing for 
appropriate action, before further flight, repair in accordance with 
paragraph (h)(1)(ii)(A) of this AD.
    (ii) If any cracking is found, before further flight, do the 
action specified in either paragraph (h)(1)(ii)(A) or (h)(1)(ii)(B) 
of this AD.
    (A) Repair in accordance with a method approved by the Manager, 
Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane 
Directorate; or in accordance with data meeting the certification 
basis of the airplane approved by a Boeing Company Designated 
Engineering Representative (DER) or Authorized Representative (AR) 
for the Boeing Delegation Option Authorization (DOA) who has been 
authorized by the Manager, Seattle ACO to make such findings. For a 
repair method to be approved by the

[[Page 13356]]

Manager, Seattle ACO, as required by this paragraph, the Manager's 
approval letter must specifically reference this AD.
    (B) Repair in accordance with Part 3 of the Accomplishment 
Instructions of the alert service bulletin; except where the alert 
service bulletin specifies to contact Boeing for appropriate action, 
before further flight, repair in accordance with paragraph 
(h)(1)(ii)(A) of this AD.
    (2) Gain access to the upper deck floor beams from below the 
upper deck floor; and perform a surface HFEC inspection to detect 
cracking of the floor beams at BS 340 and 360, and on both the left 
and right sides of the floor beam at BS 380 between BL 40 and 76; in 
accordance with Part 2 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-53A2431, Revision 2, dated June 13, 2002.
    (i) If no cracking is found, repeat the inspection required by 
paragraph (h)(2) of this AD at intervals not to exceed 750 flight 
cycles.
    (ii) If any cracking is found, before further flight, do the 
action specified in paragraph (h)(1)(ii) of this AD.

New Post-Repair Inspection

    (i) For areas repaired in accordance with paragraph (h)(1)(i)(C) 
or (h)(1)(ii)(B) of this AD: Before the accumulation of the 
applicable threshold specified in the ``New Inspection Threshold'' 
column in Table 1 of Part 3 of the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-53A2431, Revision 2, dated June 
13, 2002, after accomplishing the repair; or within 1,000 flight 
cycles after the effective date of this AD; whichever occurs later: 
Do the actions specified in paragraphs (i)(1) through (i)(3) of this 
AD, as applicable.
    (1) For locations that have been repaired by oversizing the 
fastener holes only (i.e., repair strap and/or clip not installed) 
as shown in Part 3 of the Accomplishment Instructions of Revision 1 
or 2 of the alert service bulletin: Perform an open-hole HFEC 
inspection to detect cracking of the upper deck floor beams, in 
accordance with Part 1 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-53A2431, Revision 2, dated June 13, 2002.
    (2) For locations previously repaired as shown in Figure 8 of 
Revision 1 or 2 of the alert service bulletin: Do an open-hole HFEC 
inspection to detect cracks at the fastener holes of the floor panel 
attachment and the inboard and outboard end fastener locations 
common to the repair strap, in accordance with Part 4 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2431, Revision 2, dated June 13, 2002.
    (3) For locations previously repaired as shown in Figure 9 or 
Figure 10 of Revision 1 or 2 of the alert service bulletin: Do a 
surface HFEC inspection to detect cracks at the upper chord along 
the edge of the trimmed surface; and perform an open-hole HFEC 
inspection to detect cracks at the fastener holes of the floor panel 
attachment and the inboard and outboard end fastener locations 
common to the repair strap, in accordance with Part 4 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2431, Revision 2, dated June 13, 2002.
    (j) If no crack is detected during any inspection required by 
paragraphs (i)(1) through (i)(3) of this AD, repeat the applicable 
inspection thereafter at intervals not to exceed 3,000 flight 
cycles.
    (k) If any crack is detected during any inspection required by 
paragraph (i)(1) through (i)(3) of this AD, before further flight, 
do the action specified in paragraph (h)(1)(ii)(A) of this AD.
    (l) For areas repaired in accordance with paragraph 
(h)(1)(ii)(A) of this AD that do not have a post-repair inspection 
program approved by the Manager, Seattle ACO, or according to data 
meeting the certification basis of the airplane approved by an AR 
for the Boeing DOA Organization who has been authorized by the 
Manager, Seattle ACO, to make those findings: Do the actions 
specified in paragraph (h) of this AD at the time specified in that 
paragraph.

Credit for Previous Released Alert Service Bulletin

    (m) Actions accomplished before the effective date of this AD 
per Boeing Alert Service Bulletin 747-53A2431, dated February 10, 
2000; or Revision 1, dated March 8, 2001; are acceptable for 
compliance with the applicable requirements of this AD.

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 AR 
for the Boeing DOA 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.
    (3) AMOCs, approved previously per AD 2000-14-17, amendment 39-
11600, are approved as AMOCs with paragraph (h)(1)(ii)(A) of this 
AD, provided that a post-repair inspection program has been approved 
by the Manager, Seattle ACO, or by a Boeing Company Designated 
Engineering Representative or an AR for the Boeing DOA Organization 
who has been authorized by the Manager, Seattle ACO, to make those 
findings.

Material Incorporated by Reference

    (o) You must use Boeing Alert Service Bulletin 747-53A2431, 
Revision 2, dated June 13, 2002, to perform the actions that are 
required by this AD, unless the AD specifies otherwise. The Director 
of the Federal Register approves the incorporation by reference of 
this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 
For copies of the service information, contact Boeing Commercial 
Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. For 
information on the availability of this material at the National 
Archives and Records Administration (NARA), call (202) 741-6030, or 
go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. You may view the AD docket at the 
Docket Management Facility, U.S. Department of Transportation, 400 
Seventh Street SW, room PL-401, Nassif Building, Washington, DC.

    Issued in Renton, Washington, on March 9, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-5386 Filed 3-18-05; 8:45 am]
BILLING CODE 4910-13-P