[Federal Register Volume 63, Number 197 (Tuesday, October 13, 1998)]
[Rules and Regulations]
[Pages 54569-54570]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-26966]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-185-AD; Amendment 39-10826; AD 98-21-17]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
Equipped with Pratt & Whitney Model JT9D-70 Engines
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 series airplanes, that
currently requires repetitive inspections to detect fatigue cracking of
the spring beams on the outboard struts; replacement of cracked spring
beams with new or serviceable spring beams; and follow-on actions. That
action also provides an optional terminating action for the repetitive
inspections. This amendment removes that optional terminating action,
and requires a new terminating action. This amendment is prompted by
the development of an improved process for manufacturing titanium
spring beams that will eliminate the embedded porosity flaws in the
existing spring beams from which fatigue cracking can originate. The
actions specified by this AD are intended to prevent fatigue cracking
of the spring beam, which could result in loss of an outboard strut.
DATES: Effective November 17, 1998.
The incorporation by reference of Boeing Alert Service Bulletin
747-54A2171, Revision 1, dated June 27, 1996; and Boeing Service
Bulletin 747-54-2177, dated June 27, 1996; as listed in the
regulations; is approved by the Director of the Federal Register as of
November 17, 1998.
The incorporation by reference of Boeing Alert Service Bulletin
747-54A2171, dated October 31, 1994, was approved previously by the
Director of the Federal Register as of December 22, 1994 (59 FR 63003,
December 7, 1994).
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 94-25-01,
amendment 39-9085 (59 FR 63003, December 7, 1994), which is applicable
to certain Boeing Model 747 series airplanes, was published in the
Federal Register on July 7, 1998 (63 FR 36628). The action continues to
require repetitive inspections to detect fatigue cracking of the spring
beams on the outboard struts; replacement of cracked spring beams with
new or serviceable spring beams; and follow-on actions. The action also
proposed to remove the previously optional terminating action, and
require a new terminating action.
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 comments
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 7 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 5 airplanes of U.S. registry
will be affected by this AD.
The inspections that are currently required by AD 94-25-01, and
retained in this AD, take approximately 40 work hours per airplane, per
inspection cycle, to accomplish, at an average labor rate of $60 per
work hour. Based on these figures, the cost impact of the currently
required inspections on U.S. operators is estimated to be $12,000, or
$2,400 per airplane, per inspection cycle.
The new replacement required by this AD will take approximately 376
work hours per airplane to accomplish, at an average labor rate of $60
per work hour. Required parts will cost approximately $105,000 per
airplane. Based on these figures, the cost impact of the replacement
required by this AD on U.S. operators is estimated to be $637,800, or
$127,560 per airplane.
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.
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 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.
[[Page 54570]]
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-9085 (59 FR
63003, December 7, 1994), and by adding a new airworthiness directive
(AD), amendment 39-10826, to read as follows:
98-21-17 Boeing: Amendment 39-10826. Docket 97-NM-185-AD.
Supersedes AD 94-25-01, Amendment 39-9085.
Applicability: Model 747 series airplanes, line numbers 202
through 396 inclusive, equipped with Pratt & Whitney Model JT9D-70
engines; 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 (f) 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 fatigue cracking of the spring beam, which could
result in loss of an outboard strut, accomplish the following:
(a) Prior to the accumulation of 10,000 total flight cycles, or
within 30 days after December 22, 1994 (the effective date of AD 94-
25-01), whichever occurs later, perform a detailed visual inspection
to detect fatigue cracking of the spring beams on the outboard
struts, in accordance with Boeing Alert Service Bulletin 747-
54A2171, dated October 31, 1994, or Revision 1, dated June 27, 1996.
(Remove the gap covers and fairing access panels to perform this
inspection.)
(1) If no cracking is detected, repeat the visual inspection
thereafter at intervals not to exceed 300 flight cycles until the
requirements of paragraph (d) of this AD have been accomplished.
(2) If any cracking is detected, prior to further flight,
accomplish the replacement actions specified in paragraph (d) of
this AD.
Note 2: Accomplishment of the optional terminating action
specified in paragraph (b) of AD 94-25-01 does not constitute
terminating action for the requirements of this AD.
(b) For airplanes that have accomplished terminating action in
accordance with paragraph (b) of AD 94-25-01: Within 1,000 flight
cycles after accomplishment of the terminating action specified by
AD 94-25-01, or within 90 days after the effective date of this AD,
whichever occurs later, perform a detailed visual inspection to
detect fatigue cracking of the spring beams on the outboard struts,
in accordance with Boeing Alert Service Bulletin 747-54A2171, dated
October 31, 1994, or Revision 1, dated June 27, 1996.
(1) If no cracking is detected, repeat the detailed visual
inspection thereafter at intervals not to exceed 300 flight cycles
until the requirements of paragraph (d) of this AD have been
accomplished.
(2) If any cracking is detected, prior to further flight,
accomplish the replacement actions specified in paragraph (d) of
this AD.
(c) For airplanes that have accomplished installation of the
Boeing-inspected spare titanium spring beams in accordance with
Boeing Service Bulletin 747-54A2171, Revision 1, dated June 27,
1996: Within 3,000 flight cycles after accomplishment of the
installation of the spare spring beams, or within 90 days after the
effective date of this AD, whichever occurs later, perform a
detailed visual inspection to detect fatigue cracking of the spring
beams on the outboard struts, in accordance with Boeing Alert
Service Bulletin 747-54A2171, dated October 31, 1994, or Revision 1,
dated June 27, 1996.
(1) If no cracking is detected, repeat the detailed visual
inspection thereafter at intervals not to exceed 300 flight cycles
until the requirements of paragraph (d) of this AD have been
accomplished.
(2) If any cracking is detected, prior to further flight,
accomplish the replacement actions specified in paragraph (d) of
this AD.
(d) For all airplanes: Prior to the accumulation of 10,000 total
flight cycles, or within 18 months after the effective date of this
AD, whichever occurs later, replace the spring beams on the outboard
struts with new, improved spring beams, in accordance with Boeing
Service Bulletin 747-54-2177, dated June 27, 1996. Accomplishment of
this replacement constitutes terminating action for the repetitive
inspection requirements of this AD.
(e) As of the effective date of this AD, no person shall install
a spring beam assembly, part numbers 65B89175-5, -6, -9, -10, -13, -
14, -19, and -20, on any airplane.
(f) 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 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(g) 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.
(h) The actions shall be done in accordance with Boeing Alert
Service Bulletin 747-54A2171, dated October 31, 1994, or Boeing
Alert Service Bulletin 747-54A2171, Revision 1, dated June 27, 1996;
and Boeing Service Bulletin 747-54-2177, dated June 27, 1996.
(1) The incorporation by reference of Boeing Alert Service
Bulletin 747-54A2171, Revision 1, dated June 27, 1996, and Boeing
Service Bulletin 747-54-2177, dated June 27, 1996, 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 Alert Service
Bulletin 747-54A2171, dated October 31, 1994, was approved
previously by the Director of the Federal Register as of December
22, 1994 (59 FR 63003, December 7, 1994).
(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.
(i) This amendment becomes effective on Novmeber 17, 1998.
Issued in Renton, Washington, on October 1, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-26966 Filed 10-9-98; 8:45 am]
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