AD 2004-03-11
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | 747-200C -200F | Airworthiness Directives; Boeing Model 747-200C and -200F Series Airplanes |
Unsafe Condition
Fatigue cracking in the upper chord of the upper deck floor beams, which could extend and sever floor beams at a floor panel attachment hole location, leading to rapid decompression and loss of controllability.
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Required Actions
Inspect the upper chord of the upper deck floor beams for fatigue cracking. Repair any identified cracking as necessary. For certain airplanes, an optional repair/modification is provided to extend repetitive inspection intervals.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the specified repetitive inspection intervals as outlined in the AD.
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Affected Aircraft
Boeing Model 747-200C and -200F series airplanes, as specified in the AD.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747-200C and -200F series airplanes, that requires repetitive inspections to find fatigue cracking in the upper chord of the upper deck floor beams, and repair if necessary. For certain airplanes, this amendment also provides an optional repair/ modification, which extends certain repetitive inspection intervals. This action is necessary to find and fix cracking in certain upper deck floor beams. Such cracking could extend and sever floor beams at a floor panel attachment hole location and could result in rapid decompression and consequent loss of controllability of the airplane. This action is intended to address the identified unsafe condition.
Document Text
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[Federal Register Volume 69, Number 26 (Monday, February 9, 2004)]
[Rules and Regulations]
[Pages 5920-5922]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 04-2584]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2001-NM-278-AD; Amendment 39-13455; AD 2004-03-11]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-200C and -200F Series
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Boeing Model 747-200C and -200F series airplanes,
that requires repetitive inspections to find fatigue cracking in the
upper chord of the upper deck floor beams, and repair if necessary. For
certain airplanes, this amendment also provides an optional repair/
modification, which extends certain repetitive inspection intervals.
This action is necessary to find and fix cracking in certain upper deck
floor beams. Such cracking could extend and sever floor beams at a
floor panel attachment hole location and could result in rapid
decompression and consequent loss of controllability of the airplane.
This action is intended to address the identified unsafe condition.
DATES: Effective March 15, 2004.
The incorporation by reference of a certain publication listed in
the regulations is approved by the Director of the Federal Register as
of March 15, 2004.
ADDRESSES: The service information referenced in this AD may be
obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207. This information may be examined at the Federal
Aviation Administration (FAA), Transport Airplane Directorate, Rules
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of
the Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC.
FOR FURTHER INFORMATION CONTACT: Rick Kawaguchi, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
917-6434; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to certain Boeing Model 747-200C and
-200F series airplanes was published in the Federal Register on July
24, 2003 (68 FR 43688). That action proposed to require repetitive
inspections to find fatigue cracking in the upper chord of the upper
deck floor beams, and repair if necessary. For certain airplanes, that
action also proposed an optional repair/modification, which would
extend certain repetitive inspection intervals.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Request To Allow an Additional Adjustment to the Compliance Time
One commenter requests that adjustments to the compliance time in
paragraph (c) of the proposed AD should apply not only to the actions
described in paragraph (a), but also to those described in paragraph
(b).
The FAA concurs. We find that relief of the cabin pressure
differential should be applicable to the compliance thresholds and
repetitive inspections for the optional action described in paragraph
(b) as well as those required by paragraph (a). Paragraph (c) of this
final rule has been changed accordingly.
Request To Expand Provisions for Optional Repair/Modification
One commenter suggests that paragraph (b) of the proposed AD be
revised to provide that, if the inspection required by paragraph (a) of
the proposed AD were done per Part 2 Surface High Frequency Eddy
Current (HFEC) Inspection Method of the Work Instructions of Boeing
Alert Service Bulletin 747-53A2439, then accomplishment of the optional
repair or modification specified in paragraph (b)(1) of the proposed AD
could be performed. The commenter indicates that repair per paragraph
(b)(1) of the proposed AD already requires open-hole HFEC inspection of
the floor panel hole and reworking of the hole, until any cracking is
removed. It should, therefore, be acceptable to accomplish repair
following inspection per Part 2 of the Work Instructions of the service
bulletin.
The FAA agrees that repair per paragraph (b)(1) of the proposed AD
requires open hole HFEC inspection of the floor panel hole and re-
working of the hole, until any cracking is removed. We find, therefore,
that following inspection per Part 2 of the Work Instructions of the
service bulletin, the repair may be accomplished per paragraph (b)(1).
We have revised paragraph (b) of the final rule accordingly.
Request To Clarify Location of Fatigue Cracking
One commenter asks that the Discussion section of the proposed AD
be revised to refer to STA 420, rather than STA 340. The commenter also
asks that the language in the Discussion section and in the third
paragraph of the introduction of the proposed AD be changed from ``* *
* could extend and sever floor beams adjacent to the body frame * * *''
to ``* * * could extend and sever floor beams at a floor panel hole
location * * *.''
The commenter notes that the Background section of Boeing Alert
Service Bulletin 747-53A2439 indicates that fatigue cracking was
reported at STA 420 rather than at STA 340. The commenter also notes
that the applicable inspections and possible repair or modification is
at the upper deck floor beam floor panel attachment holes, which exist
throughout the span of the floor beams, not just adjacent to where the
floor beam joins the body frame.
The FAA partially concurs with the comment. No change is needed in
the Discussion section, since that section is not restated in this
final rule. In terms
[[Page 5921]]
of the location where the floor beams can sever, the suggested change
has been made in the summary section and in the regulatory text of this
final rule.
Conclusion
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule with the changes previously
described. The FAA has determined that these changes will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Change to Labor Rate Estimate
We have 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 $60 per work
hour to $65 per work hour. The cost impact information, below, reflects
this increase in the specified hourly labor rate.
Cost Impact
There are approximately 78 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 21 airplanes of U.S. registry
will be affected by this AD, that it will take approximately 30 work
hours per airplane to accomplish the required inspections, and that the
average labor rate is $65 per work hour. Based on these figures, the
cost impact of the AD on U.S. operators is estimated to be $40,950, or
$1,950 per airplane, per inspection.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the requirements of this AD
action, and that no operator would accomplish those actions in the
future if this AD were not adopted. The cost impact figures discussed
in AD rulemaking actions represent only the time necessary to perform
the specific actions actually required by the AD. These figures
typically do not include incidental costs, such as the time required to
gain access and close up, planning time, or time necessitated by other
administrative actions.
Regulatory Impact
The regulations adopted herein 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. Therefore, it
is determined that this final rule does not have federalism
implications under Executive Order 13132.
For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it may be obtained
from the Rules Docket at the location provided under the caption
ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
0
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration 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. Section 39.13 is amended by adding the following new airworthiness
directive:
2004-03-11 Boeing: Amendment 39-13455. Docket 2001-NM-278-AD.
Applicability: Model 747-200C and -200F series airplanes, as
listed in Boeing Alert Service Bulletin 747-53A2439, dated July 5,
2001; certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To find and fix cracking in certain upper deck floor beams,
which could extend and sever floor beams at a floor panel attachment
hole location and could result in rapid decompression and consequent
loss of controllability of the airplane, accomplish the following:
Inspections and Repair
(a) Before the accumulation of 22,000 total flight cycles, or
within 1,000 flight cycles after the effective date of this AD,
whichever is later: Do the applicable inspection to find fatigue
cracking in the upper chord of the upper deck floor beams as
specified in Part 1 (Open-Hole High Frequency Eddy Current (HFEC)
Inspection Method) or Part 2 (Surface HFEC Inspection Method) of the
Work Instructions of Boeing Alert Service Bulletin 747-53A2439,
dated July 5, 2001. Do the inspections per the service bulletin.
(1) If any crack is found, before further flight, repair per
Part 3 (Repair) of the Work Instructions of the service bulletin;
except where the service bulletin specifies to contact Boeing for
appropriate action, before further flight, repair according to a
method approved by the Manager, Seattle Aircraft Certification
Office (ACO), FAA; or according to data meeting the type
certification basis of the airplane approved by a Boeing Company
Designated Engineering Representative (DER) who has been authorized
by the Manager, Seattle ACO, to make such findings. For a repair
method to be approved by the Manager, Seattle ACO, as required by
this paragraph, the Manager's approval letter must specifically
reference this AD. Do the applicable inspection of the repaired area
per Part 1 of the service bulletin at the applicable time per Part 3
of the service bulletin. Repeat the applicable inspection at the
applicable interval per Figure 1 of the service bulletin.
(2) If no crack is found, repeat the applicable inspection per
paragraph (a) of this AD within the applicable interval per Figure 1
of the service bulletin. As an option, accomplishment of paragraph
(b)(1) or (b)(2) of this AD, before further flight, extends the
threshold for the initiation of the repetitive inspections required
by this paragraph.
Optional Repair/Modification
(b) For airplanes on which the inspection required by paragraph
(a) of this AD is done per Part 1 of the Work Instructions of Boeing
Alert Service Bulletin 747-53A2439, dated July 5, 2001; and on which
no cracking is found: Accomplishment of the actions specified in
either paragraph (b)(1) or (b)(2) of this AD extends the threshold
for the initiation of the repetitive inspections required by
paragraph (a)(2) of this AD. For airplanes on which the inspection
required by paragraph (a) of this AD is done per Part 2 of the Work
Instructions of Boeing Alert Service Bulletin 747-53A2439, dated
July 5, 2001; and on which no cracking is found: Accomplishment of
the actions specified in paragraph (b)(1) of this AD extends the
threshold for the initiation of the repetitive inspections required
by paragraph (a)(2) of this AD.
(1) Do the repair per Part 3 of the service bulletin. At the
applicable time specified in Table 1 of Part 3 of the service
bulletin, do the inspection of the repaired area per Part 1 of the
service bulletin. Repeat the inspection thereafter within the
applicable interval per Figure 1 of the service bulletin.
(2) Do the modification of the attachment hole of the floor
panel per Figure 5 of the service bulletin. Within 10,000 flight
cycles after accomplishment of the modification, do the inspection
of the modified area per Part 1 of the service bulletin. Repeat the
inspection thereafter within the applicable interval per Figure 1 of
the service bulletin.
Adjustments to Compliance Time: Cabin Differential Pressure
(c) For the purposes of calculating the compliance threshold and
repetitive intervals for actions described in paragraphs (a) and (b)
of this AD: The number of flight cycles
[[Page 5922]]
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
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.
Alternative Methods of Compliance
(d)(1) In accordance with 14 CFR 39.19, the Manager, Seattle
ACO, is authorized to approve alternative methods of compliance
(AMOCs) for this AD.
(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 a
Boeing Company DER who has been authorized by the Manager, Seattle
ACO, to make such findings.
Incorporation by Reference
(e) Unless otherwise specified in this AD, the actions shall be
done in accordance with Boeing Alert Service Bulletin 747-53A2439,
dated July 5, 2001. This incorporation by reference was approved by
the Director of the Federal Register in accordance with 5 U.S.C.
552(a) and 1 CFR part 51. Copies may be obtained from Boeing
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.
Copies may be inspected at the FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington; or at the Office of the
Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC.
Effective Date
(f) This amendment becomes effective on March 15, 2004.
Issued in Renton, Washington, on January 29, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-2584 Filed 2-6-04; 8:45 am]
BILLING CODE 4910-13-P
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Rights: U.S. Government Public Domain
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