[Federal Register Volume 63, Number 141 (Thursday, July 23, 1998)]
[Rules and Regulations]
[Pages 39487-39489]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-19455]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-82-AD; Amendment 39-10672; AD 98-15-21]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-100 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to certain Boeing Model 747-100 series airplanes, that
currently requires repetitive inspections to detect cracking of the
wing front spar web above engine numbers 2 and 3, and to detect cracked
or broken fasteners in the web; and repair, if necessary. That AD also
provides an optional terminating action for the repetitive inspections.
This amendment requires various improved inspections. This amendment is
prompted by a report indicating that the existing inspections do not
adequately detect vertical cracks. The actions specified by this AD are
intended to prevent fuel leakage onto an engine and a resultant fire
due to cracked or broken fasteners in the wing front spar.
DATES: Effective August 27, 1998.
The incorporation by reference of Boeing Alert Service Bulletin
747-57A2266, Revision 5, dated August 3, 1995, as listed in the
regulations, is approved by the Director of the Federal Register as of
August 27, 1998.
The incorporation by reference of Boeing Service Bulletin 747-
57A2266, Revision 3, dated March 31, 1994; and Boeing Service Bulletin
747-57A2266, Revision 4, dated November 3, 1994, was approved
previously by the Director of the Federal Register as of March 23, 1995
(60 FR 9613, February 21, 1995).
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: Tamara L. Anderson, Aerospace
Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue,
SW., Renton, Washington 98055-4056; telephone (425) 227-2771; fax (425)
227-1181.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding AD 95-02-15,
amendment 39-9134 (60 FR 9613, February 21, 1995), which is applicable
to certain Boeing Model 747-100 series airplanes, was published in the
Federal Register on April 14, 1998 (63 FR 18167). The action proposed
to supersede AD 95-02-15 to continue to require repetitive inspections
to detect cracking of the wing front spar web above engine numbers 2
and 3, and to detect cracked or broken fasteners in the web; and
repair, if necessary. That action also continues to provide for an
optional terminating action for the repetitive inspections. The action
proposed to require various improved inspections.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the single comment received.
The commenter supports the proposed rule.
Conclusion
After careful review of the available data, including the comment
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule as proposed.
Cost Impact
There are approximately 190 Boeing Model 747-100 series airplanes
of the affected design in the worldwide fleet. The FAA estimates that
95 airplanes of U.S. registry will be affected by this AD.
The actions that are currently required by AD 95-02-15, and
retained in this AD, take approximately 70 work hours per airplane to
accomplish, at an average labor rate of $60 per work hour. Based on
these figures, the cost impact of the currently required inspection on
U.S. operators is estimated to be $399,000, or $4,200 per airplane, per
inspection cycle.
For airplanes identified as Configuration A in the referenced alert
service bulletin, the new actions that are required in this AD will
take approximately 60 work hours per airplane to accomplish, at an
average labor rate of $60 per work hour. Based on these figures, the
cost impact of the new inspection requirements of this AD on those U.S.
operators is estimated to be $3,600 per airplane, per inspection cycle.
For airplanes identified as Configuration B in the referenced alert
service bulletin, the new actions that are required in this AD will
take approximately 40 work hours per airplane to accomplish, at an
average labor rate of $60 per work hour. Based on these figures, the
cost impact of the new inspection requirements of this AD on U.S.
operators is estimated to be $2,400 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.
Should an operator elect to accomplish the optional terminating
action (fastener replacement between FSS 570 and FSS 684) that is
provided by this AD action, it would take approximately 306 work hours
to accomplish it, at an average labor rate of $60 per work hour. The
cost of required parts would be approximately $15,478. Based on these
figures, the cost impact of the optional terminating action will be
$33,838 per airplane.
Regulatory Impact
The regulations adopted herein will not have substantial direct
effects 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, in
accordance with Executive Order 12612, it is determined that this final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
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
[[Page 39488]]
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 39-9134 (60 FR
9613, February 21, 1995), and by adding a new airworthiness directive
(AD), amendment 39-10672, to read as follows:
98-15-21 Boeing: Amendment 39-10672. Docket 97-NM-82-AD. Supersedes
AD 95-02-15, Amendment 39-9134.
Applicability: Model 747-100 series airplanes; as listed in
Boeing Alert Service Bulletin 747-57A2266, Revision 5, dated August
3, 1995; 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) 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 prevent fuel leakage onto an engine and a resultant fire,
accomplish the following:
Restatement of Requirements of AD 95-02-15, Amendment 39-9134
(a) For airplanes on which the terminating action (fastener
replacement) specified in Boeing Service Bulletin 747-57A2266, dated
June 6, 1991; Revision 1, dated May 21, 1992; or Revision 2, dated
June 10, 1993; has not been accomplished: Prior to the accumulation
of 13,000 total flight cycles, or within 9 months after March 23,
1995 (the effective date of AD 95-02-15, amendment 39-9134), or
within 2,000 flight cycles after the immediately preceding
inspection accomplished in accordance with AD 92-07-11, amendment
39-8207, whichever occurs latest, accomplish the inspections
specified in paragraphs (a)(1), (a)(2), and (a)(3) of this AD in
accordance with Boeing Service Bulletin 747-57A2266, Revision 3,
dated March 31, 1994, or Revision 4, dated November 3, 1994. Repeat
these inspections thereafter at intervals not to exceed 2,000 flight
cycles until the inspections required by paragraph (c) or (d) of
this AD, as applicable, are accomplished.
(1) Perform a detailed visual inspection to detect cracking of
the wing front spar chords, stiffeners, and rib posts between the
fastener heads between FSS 570 and FSS 684; and
(2) Perform an ultrasonic inspection of the web under the upper
and lower chord footprints to detect cracking of the wing front spar
web between FSS 570 and FSS 684; and
(3) Perform an ultrasonic inspection of the fasteners in the
web-to-chords, and of the fasteners in the top two and bottom two
rows in the web-to-stiffeners and web-to-rib posts of the wing front
spar to detect cracked or broken fasteners between FSS 570 and FSS
684.
(b) For airplanes on which the terminating action (fastener
replacement) specified in Boeing Service Bulletin 747-57A2266, dated
June 6, 1991; Revision 1, dated May 21, 1992; or Revision 2, dated
June 10, 1993; has been accomplished: Within 18 months after
accomplishing the terminating action specified in the original
issue, Revision 1, or Revision 2 of the service bulletin, or within
9 months after March 23, 1995, whichever occurs later, accomplish
the inspections specified in paragraphs (b)(1), (b)(2), and (b)(3)
of this AD, in accordance with Boeing Service Bulletin 747-57A2266,
Revision 3, dated March 31, 1994, or Revision 4, dated November 3,
1994. Repeat these inspections thereafter at intervals not to exceed
2,000 flight cycles until the inspections required by paragraph (c)
or (d) of this AD, as applicable, are accomplished.
(1) Perform a detailed visual inspection of the wing front spar
chords, stiffeners, and rib posts between the fastener heads between
FSS 570 and FSS 684; and
(2) Perform an ultrasonic inspection of the web under the upper
and lower chord footprints to detect cracking of the wing front spar
web between FSS 570 and FSS 636 and between FSS 675 and FSS 684; and
(3) Perform an ultrasonic inspection of the fasteners in the
web-to-chords, and of the fasteners in the top two rows and bottom
two rows in the web-to-stiffeners and web-to-rib posts of the wing
front spar to detect cracked or broken fasteners between FSS 570 and
FSS 636 and between FSS 675 and 684.
New Requirements of this AD
(c) For airplanes identified as Configuration A in Boeing Alert
Service Bulletin 747-57A2266, Revision 5, dated August 3, 1995:
Prior to the accumulation of 13,000 total flight cycles, or within 6
months after the effective date of this AD, or within 2,000 flight
cycles after the immediately preceding inspection accomplished in
accordance with paragraph (a) or (b) of this AD, whichever occurs
latest, accomplish the inspections specified in paragraphs (c)(1),
(c)(2), (c)(3), and (c)(4) of this AD, in accordance with Figure 3
of Boeing Alert Service Bulletin 747-57A2266, Revision 5, dated
August 3, 1995. Repeat these inspections thereafter at intervals not
to exceed 2,000 flight cycles. Accomplishment of these inspections
terminates the inspections required by paragraphs (a) and (b) of
this AD.
(1) Perform a detailed visual inspection to detect damage and
fuel leaks in the general area of the web of the wing front spar
between FSS 570 and FSS 684.
(2) Perform an eddy current inspection to detect cracks along
the web near the edges of the vertical flange of the upper and lower
chords of the wing front spar between FSS 570 and FSS 684.
(3) Perform an ultrasonic inspection to detect cracks in the web
around the first two fastener holes in the stiffeners and rib posts
between FSS 570 and FSS 684.
(4) Perform an ultrasonic inspection to detect cracked or broken
fasteners in the fasteners attaching only the web to the chords, in
the top two and bottom two rows of the fasteners attaching the web
to the stiffeners, and in the top two and bottom two rows of the
fasteners attaching the web to the rib posts. This inspection area
is located between FSS 570 and FSS 684.
(d) For airplanes identified as Configuration B in Boeing Alert
Service Bulletin 747-57A2266, Revision 5, dated August 3, 1995:
Within 18 months following accomplishment of the terminating action
(fastener replacement) specified in Boeing Service Bulletin 747-
57A2266, dated June 6, 1991, Revision 1, dated May 21, 1992, or
Revision 2, dated June 10, 1993; or within 12 months after the
effective date of this AD; or within 2,000 flight cycles after the
immediately preceding inspection accomplished in accordance with
paragraph (a) or (b) of this AD; whichever occurs latest; accomplish
the inspections specified in paragraphs (d)(1), (d)(2), (d)(3), and
(d)(4) of this AD in accordance with Figure 4 of Boeing Alert
Service Bulletin 747-57A2266, Revision 5, dated August 3, 1995.
Repeat these inspections thereafter at intervals not to exceed 2,000
flight cycles. Accomplishment of these inspections terminates the
inspections required by paragraphs (a) and (b) of this AD.
(1) Perform a detailed visual inspection to detect damage and
fuel leaks in the general area of the web of the wing front spar
between FSS 570 and FSS 636 and between FSS 675 and FSS 684.
(2) Perform an eddy current inspection to detect cracks along
the web near the edges of the vertical flange of the upper and lower
chords of the wing front spar between FSS 570 and FSS 636 and
between FSS 675 and FSS 684.
(3) Perform an ultrasonic inspection to detect cracks in the web
around the first two fastener holes in the stiffeners and rib posts
between FSS 570 and FSS 636 and between FSS 675 and FSS 684.
(4) Perform an ultrasonic inspection to detect cracked or broken
fasteners in the fasteners attaching only the web to the chords, in
the top two and bottom two rows of the fasteners attaching the web
to the
[[Page 39489]]
stiffeners, and in the top two and bottom two rows of the fasteners
attaching the web to the rib posts. This inspection area is located
between FSS 570 and FSS 636 and between FSS 675 and FSS 684.
(e) If any discrepancy (i.e., cracking, fuel leakage, broken
fasteners) is detected during any inspection required by this AD,
prior to further flight, repair in accordance with paragraphs E. and
H. (as applicable) of the Accomplishment Instructions of Boeing
Service Bulletin 747-57A2266, Revision 3, dated March 31, 1994;
Boeing Service Bulletin 747-57A2266, Revision 4, dated November 3,
1994; or Boeing Alert Service Bulletin 747-57A2266, Revision 5,
dated August 3, 1995. Thereafter, continue to inspect the remaining
fasteners in accordance with paragraph (c) or (d) of this AD, as
applicable, until the terminating action specified in paragraph (f)
of this AD is accomplished. If any crack is found that cannot be
removed by oversizing the fastener hole, prior to further flight,
repair it in accordance with a method approved by the Manager,
Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane
Directorate.
(f) Replacement of the fasteners in the web-to-chords and of the
fasteners in the web-to-stiffeners and web-to-rib posts, as
specified in Boeing Service Bulletin 747-57A2266, Revision 3, dated
March 31, 1994; Revision 4, dated November 3, 1994; or Revision 5,
dated August 3, 1995; with oversized fasteners on each wing spar in
accordance with the service bulletin constitutes terminating action
for the repetitive inspections required by paragraphs (a), (b), (c),
(d), and (e) of this AD.
(g) 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 Aircraft Certification
Office (ACO), FAA, Transport Airplane Directorate. 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.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(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.
(i) The actions shall be done in accordance with Boeing Service
Bulletin 747-57A2266, Revision 3, dated March 31, 1994; Boeing
Service Bulletin 747-57A2266, Revision 4, dated November 3, 1994;
and Boeing Alert Service Bulletin 747-57A2266, Revision 5, dated
August 3, 1995.
(1) The incorporation by reference of Boeing Alert Service
Bulletin 747-57A2266, Revision 5, dated August 3, 1995, is approved
by the Director of the Federal Register in accordance with 5 U.S.C.
552(a) and 1 CFR part 51.
(2) The incorporation by reference of Boeing Service Bulletin
747-57A2266, Revision 3, dated March 31, 1994; and Boeing Service
Bulletin 747-57A2266, Revision 4, dated November 3, 1994, was
approved previously by the Director of the Federal Register as of
March 23, 1995 (60 FR 9613, February 21, 1995).
(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.
(j) This amendment becomes effective on August 27, 1998.
Issued in Renton, Washington, on July 15, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-19455 Filed 7-22-98; 8:45 am]
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