[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]
BILLING CODE 4910-13-P