AD 2001-15-03
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | 747 | Airworthiness Directives; Boeing Model 747 Series Airplanes |
Unsafe Condition
Fatigue cracking of the forward and aft inner chords, the frame support, and the splice fitting of the forward inner chord of the upper corner of the station 2598 bulkhead, which could result in reduced structural capability of the bulkhead and the inability of the structure to carry horizontal stabilizer flight loads.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Perform a high frequency eddy current inspection (HFEC) to detect cracking of the forward and aft inner chords and the splice fitting of the forward inner chord of the station 2598 bulkhead. Perform a detailed visual inspection to detect cracking of the same areas. Repeat inspections at intervals not to exceed 3,000 flight cycles.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 1,000 flight cycles after June 5, 2000, or prior to the accumulation of 13,000 total flight cycles, whichever occurs later.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Model 747 series airplanes, line numbers 1 through 1307 inclusive, certificated in any category.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
This amendment supersedes an existing airworthiness directive (AD), applicable to all Boeing Model 747 series airplanes, that currently requires repetitive inspections to detect cracking of the forward and aft inner chords and the splice fitting of the forward inner chord of the station 2598 bulkhead, and repair, if necessary. This amendment adds repetitive inspections of an expanded inspection area, which ends the inspections specified in the existing AD. This amendment also limits the applicability of the existing AD. This amendment is prompted by reports indicating that fatigue cracking was found on airplanes that had accumulated fewer total flight cycles than the threshold specified in the existing AD. The actions specified by this AD are intended to detect and correct fatigue cracking of the forward and aft inner chords, the frame support, and the splice fitting of the forward inner chord of the upper corner of the station 2598 bulkhead, which could result in reduced structural capability of the bulkhead and the inability of the structure to carry horizontal stabilizer flight loads.
Document Text
Show stored source text (verify against official source)
[Federal Register Volume 66, Number 142 (Tuesday, July 24, 2001)]
[Rules and Regulations]
[Pages 38365-38367]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-18139]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2000-NM-331-AD; Amendment 39-12337; AD 2001-15-03]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to all Boeing Model 747 series airplanes, that
currently requires repetitive inspections to detect cracking of the
forward and aft inner chords and the splice fitting of the forward
inner chord of the station 2598 bulkhead, and repair, if necessary.
This amendment adds repetitive inspections of an expanded inspection
area, which ends the inspections specified in the existing AD. This
amendment also limits the applicability of the existing AD. This
amendment is prompted by reports indicating that fatigue cracking was
found on airplanes that had accumulated fewer total flight cycles than
the threshold specified in the existing AD. The actions specified by
this AD are intended to detect and correct fatigue cracking of the
forward and aft inner chords, the frame support, and the splice fitting
of the forward inner chord of the upper corner of the station 2598
bulkhead, which could result in reduced structural capability of the
bulkhead and the inability of the structure to carry horizontal
stabilizer flight loads.
DATES: Effective August 28, 2001.
The incorporation by reference of Boeing Alert Service Bulletin
747-53A2427, Revision 2, October 5, 2000, as listed in the regulations,
is approved by the Director of the Federal Register, as of August 28,
2001.
The incorporation by reference of Boeing Alert Service Bulletin
747-53A2427, dated December 17, 1998; and Boeing Alert Service Bulletin
747-53A2427, Revision 1, dated October 28, 1999; as listed in the
regulations, was approved previously by the Director of the Federal
Register as of June 5, 2000 (65 FR 25281, May 1, 2000).
ADDRESSES: The service information referenced in this AD may be
obtained from Boeing Commercial Airplane Group, 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)
227-1153; fax (425) 227-1181.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding AD 2000-08-21,
amendment 39-11707 (65 FR 25281, May 1, 2000), which is applicable to
all Boeing Model 747 series airplanes, was published in the Federal
Register on April 19, 2001 (66 FR 20111). The action proposed to
continue to require repetitive inspections to detect cracking of the
forward and aft inner chords and the splice fitting of the forward
inner chord of the station 2598 bulkhead, and repair, if necessary. The
action also proposed to add repetitive inspections of an expanded
inspection area, which would end the inspections specified in the
existing AD, and to limit the applicability of the existing AD.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. No comments were submitted in response
to the proposal or the FAA's determination of the cost to the public.
Conclusion
The FAA has determined that air safety and the public interest
require the adoption of the rule as proposed.
Cost Impact
There are approximately 1,115 Model 747 series airplanes of the
affected design in the worldwide fleet. The FAA estimates that 258
airplanes of U.S. registry will be affected by this AD.
The high frequency eddy current (HFEC) inspection that currently is
required by AD 2000-08-21 takes approximately 2 work hours per airplane
to accomplish, at an average labor rate of $60 per work hour. Based on
these figures, the cost impact of this inspection is estimated to be
$120 per airplane.
The detailed visual inspection that currently is required by AD
2000-08-21 takes approximately 2 work hours per airplane to accomplish,
at an average labor rate of $60 per work hour. Based on these figures,
the cost impact of this inspection is estimated to be $120 per
airplane, per inspection cycle.
The HFEC inspections that are required by this new AD will take
approximately 2 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of this inspection is estimated to be $120 per airplane, per
inspection cycle.
The cost impact figures discussed above are 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,
[[Page 38366]]
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
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
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]
2. Section 39.13 is amended by removing amendment 39-11707 (65 FR
25281, May 1, 2000) and by adding a new airworthiness directive (AD),
amendment 39-12337, to read as follows:
2001-15-03 Boeing: Amendment 39-12337. Docket 2000-NM-331-AD.
Supersedes AD 2000-08-21, Amendment 39-11707.
Applicability: Model 747 series airplanes, line numbers 1
through 1307 inclusive, certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (g)(1)
of this AD. The request should include an assessment of the effect
of the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To detect and correct cracking of the forward and aft inner
chords, the frame support, and the splice fitting of the forward
inner chord of the upper corner of the station 2598 bulkhead, which
could result in reduced structural capability of the bulkhead and
the inability of the structure to carry horizontal stabilizer flight
loads, accomplish the following:
Restatement of Requirements of AD
2000-08-21
Initial Inspection
(a) Prior to the accumulation of 13,000 total flight cycles, or
within 1,000 flight cycles after June 5, 2000 (the effective date of
AD 2000-08-21, amendment 39-11707), whichever occurs later:
Accomplish the requirements specified in paragraphs (a)(1) and
(a)(2) of this AD.
(1) Perform a high frequency eddy current inspection (HFEC) to
detect cracking of the forward and aft inner chords of the station
2598 bulkhead, in accordance with Boeing Alert Service Bulletin 747-
53A2427, dated December 17, 1998; or in accordance with Figure 2,
Steps 1 and 2, of Boeing Alert Service Bulletin 747-53A2427,
Revision 1, dated October 28, 1999.
(2) Perform an HFEC inspection to detect cracking of the splice
fitting along the upper and lower attachment to the forward inner
chord of the station 2598 bulkhead, as shown in Figure 2, Detail A,
of Boeing Alert Service Bulletin 747-53A2427, dated December 17,
1998; or in accordance with Figure 2, Step 3, of Boeing Alert
Service Bulletin 747-53A2427, Revision 1, dated October 28, 1999.
Note 2: Operators should note that, although the splice fitting
is NOT highlighted in Figure 2, Detail A, of Boeing Alert Service
Bulletin 747-53A2427, dated December 17, 1998, as it is in Figure 2
of Boeing Alert Service Bulletin 747-53A2427, Revision 1, dated
October 28, 1999, the inspection required by paragraph (a)(2) of
this AD must still be accomplished.
Repetitive Inspections
(b) Within 3,000 flight cycles after accomplishment of the
inspections required by paragraph (a) of this AD: Accomplish the
inspections specified in paragraphs (b)(1) and (b)(2) of this AD.
Repeat the inspections thereafter at intervals not to exceed 3,000
flight cycles.
(1) Perform a detailed visual inspection to detect cracking of
the forward and aft inner chords of the station 2598 bulkhead, in
accordance with Boeing Alert Service Bulletin 747-53A2427, dated
December 17, 1998; or in accordance with Figure 3, Steps 1 and 2, of
Boeing Alert Service Bulletin 747-53A2427, Revision 1, dated October
28, 1999.
Note 3: For the purposes of this AD, a detailed visual
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 mirror, magnifying lenses, etc., may be used. Surface cleaning
and elaborate access procedures may be required.''
(2) Perform a detailed visual inspection to detect cracking of
the splice fitting along the upper and lower attachment to the
forward inner chord of the station 2598 bulkhead, as shown in Figure
3, Detail A, of Boeing Alert Service Bulletin 747-53A2427, dated
December 17, 1998; or in accordance with Figure 3, Step 3, of Boeing
Alert Service Bulletin 747-53A2427, Revision 1, dated October 28,
1999.
Note 4: Operators should note that, although the splice fitting
is NOT highlighted in Figure 3, Detail A, of Boeing Alert Service
Bulletin 747-53A2427, dated December 17, 1998, as it is in Figure 3
of Boeing Alert Service Bulletin 747-53A2427, Revision 1, dated
October 28, 1999, the inspections required by paragraph (b)(2) of
this AD must still be accomplished.
Repair
(c) If any cracking is detected during the inspections required
by paragraph (a)(1) or (b)(1) of this AD, prior to further flight,
repair in accordance with Boeing Alert Service Bulletin 747-53A2427,
dated December 17, 1998, Revision 1, dated October 28, 1999, or
Revision 2, dated October 5, 2000; except as provided by paragraph
(d) of this AD.
(d) If any cracking is detected during the inspections required
by paragraph (a)(2) or (b)(2) of this AD, or the alert service
bulletin specifies that the manufacturer may be contacted for
disposition of certain repair conditions, prior to further flight,
repair in accordance with a method approved by the Manager, Seattle
Aircraft Certification Office (ACO); or in accordance with 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 approval letter must specifically
reference this AD.
New Requirements of This AD
Repetitive Inspections
(e) Do a surface HFEC inspection of the forward and aft inner
chords, the frame support, and the splice fitting of the forward
inner chord of the upper corner of the station 2598 bulkhead to find
cracking, in accordance with Boeing Alert Service Bulletin 747-
53A2427, Revision 2, dated October 5, 2000; at the latest of the
times specified in paragraphs (e)(1) and (e)(2) of this AD, as
applicable. Repeat the inspection after that at intervals not to
exceed 1,500 flight cycles. Doing these inspections ends the
inspections required by paragraphs (a) and (b) of this AD.
(1) For airplanes having line numbers 1 through 1241 inclusive:
(i) Before the accumulation of 6,000 total flight cycles.
[[Page 38367]]
(ii) Within 500 flight cycles after the effective date of this
AD.
(iii) If the inspections specified in paragraph (a) or (b) of
this AD were done before the effective date of this AD: Within 1,500
flight cycles after accomplishment of the last inspection required
by paragraph (a) or (b) of this AD, as applicable.
(2) For airplanes having line numbers 1242 through 1307
inclusive:
(i) Before the accumulation of 16,000 total flight cycles.
(ii) Within 500 flight cycles after the effective date of this
AD.
(iii) If the inspections specified in paragraph (a) or (b) of
this AD were done before the effective date of this AD: Within 1,500
flight cycles after accomplishment of the last inspection required
by paragraph (a) or (b) of this AD, as applicable.
Repair
(f) If any cracking is found during the inspections required by
paragraph (e) of this AD, before further flight, repair in
accordance with Boeing Alert Service Bulletin 747-53A2427, Revision
2, dated October 5, 2000; except where the alert service bulletin
specifies that the manufacturer may be contacted for disposition of
certain repair conditions, before further flight, repair in
accordance with a method approved by the Manager, Seattle ACO; or in
accordance with data meeting the type certification basis of the
airplane approved by a Boeing Company 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 approval letter must specifically reference this AD.
Alternative Methods of Compliance
(g)(1) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Seattle ACO. Operators shall submit
their requests through an appropriate FAA Principal Maintenance
Inspector, who may add comments and then send it to the Manager,
Seattle ACO.
(2) Alternative methods of compliance, approved previously per
AD 2000-08-21, amendment 39-11707, are approved as alternative
methods of compliance with paragraphs (c) and (d) of this AD.
Note 5: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
Special Flight Permits
(h) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be accomplished.
Incorporation by Reference
(i) Except as provided by paragraphs (d) and (f) of this AD, the
actions shall be done in accordance with Boeing Alert Service
Bulletin 747-53A2427, dated December 17, 1998; Boeing Alert Service
Bulletin 747-53A2427, Revision 1, dated October 28, 1999; or Boeing
Alert Service Bulletin 747-53A2427, Revision 2, dated October 5,
2000; as applicable.
(1) The incorporation by reference of Boeing Alert Service
Bulletin 747-53A2427, Revision 2, dated October 5, 2000, is approved
by the Director of the Federal Register as of August 28, 2001.
(2) The incorporation by reference of Boeing Alert Service
Bulletin 747-53A2427, dated December 17, 1998; and Boeing Alert
Service Bulletin 747-53A2427, Revision 1, dated October 28, 1999;
was approved previously by the Director of the Federal Register as
of June 5, 2000 (65 FR 25281, May 1, 2000).
(3) Copies may be obtained from Boeing Commercial Airplane
Group, 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
(j) This amendment becomes effective on August 28, 2001.
Issued in Renton, Washington, on July 13, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 01-18139 Filed 7-23-01; 8:45 am]
BILLING CODE 4910-13-P
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.