[Federal Register Volume 60, Number 191 (Tuesday, October 3, 1995)]
[Rules and Regulations]
[Pages 51705-51707]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-23914]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 94-NM-255-AD; Amendment 39-9383; AD 95-20-05]
Airworthiness Directives; Boeing Model 747 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 series airplanes, that
currently requires repetitive inspections for cracking in the inboard
strut-to-diagonal brace attach fittings, and repair or replacement, if
necessary. This amendment requires an additional inspection of those
attach fittings, and additional inspections in an area beyond that
specified in the existing AD. This amendment also provides an optional
terminating action for the required inspections, and expands the
applicability of the existing AD to include additional airplanes. This
amendment is prompted by reports of cracking and severing of the attach
fittings. The actions specified by this AD are intended to prevent
failure of the strut and separation of an engine from the airplane due
to cracking of the inboard strut-to-diagonal brace attach fittings.
DATES: Effective November 2, 1995.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of November 2, 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: Tim Backman, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-2797; fax (206) 227-1149.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding AD 79-17-07,
amendment 39-3533 (44 FR 50033, August 27, 1979), which is applicable
to certain Boeing Model 747 series airplanes, was published in the
Federal Register on April 4, 1995 (60 FR 17030). The action proposed to
continue to require repetitive visual inspections to detect cracking in
the inboard strut-to-diagonal brace attach fittings, and replacement or
repair of the cracking, if necessary. The action also proposed to add
repetitive high frequency eddy current (HFEC) inspections to detect
cracks of the attach fittings. Additionally, that action proposed to
require that certain attach fittings with cracks be reinspected at
shorter intervals, and to require subsequent replacement of the attach
fittings of airplanes with certain known cracking. The action also
proposed to expand the applicability of the rule to include additional
affected airplanes, and provided an optional terminating action for the
required inspections.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due
[[Page 51706]]
consideration has been given to the comments received.
One commenter supports the proposed rule.
The Air Transport Association (ATA), on behalf of one of its
members, requests that the FAA clarify that replacement of the aluminum
attach fittings with steel ones, as described in revisions prior to
Boeing Service Bulletin 747-54-2062, Revision 7, dated December 21,
1994, is an acceptable terminating action for the requirements of this
AD.
The FAA concurs. This AD does not require any further action for
operators that have replaced the aluminum fittings with steel ones, in
accordance with Revisions 1 through 7 of Boeing Service Bulletin 747-
54-2062. A note has been added to the final rule to reflect this
clarification.
The commenter also requests that the proposed rule be clarified to
specify that, for airplanes on which the fitting replacement has been
accomplished, additional work would not be required to terminate the
requirements of the AD, i.e., installation of the closure web and
installation of anvil swaged bushings.
The FAA concurs. The additional work referenced by the commenter is
not required to be accomplished as part of this AD. However, the
installation of the closure web and installation of anvil swaged
bushings, as described in Revision 7 of the service bulletin, are
required to be accomplished as part of the strut modification program,
mandated by AD 95-10-16, amendment 39-9233 (60 FR 27008, May 22, 1995),
regardless of whether or not the aluminum attach fittings have been
replaced with steel fittings. Table 2 of Boeing Service Bulletin 747-
54A2159, ``Prior or Concurrent Service Bulletins'' (which is cited in
AD 95-10-16), specifies that Boeing Service Bulletin 747-54-2062,
Revision 7, dated December 21, 1994 (which is cited in this AD), must
be accomplished prior to or concurrent with the installations required
by AD 95-10-16. A note has been added to the final rule to clarify this
point.
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.
There are approximately 367 Model 747 series airplanes of the
affected design in the worldwide fleet. The FAA estimates that 152
airplanes of U.S. registry will be affected by this AD.
The new actions that are required by this AD will take
approximately 11 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Based on these figures, the total cost
impact on U.S. operators of the new requirements of this AD is
estimated to be $100,320, or $660 per airplane, per inspection cycle.
This total cost impact figure 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.
Should an operator elect to accomplish the terminating modification
that would be provided by this AD action, it will take approximately
176 work hours per airplane to accomplish it, at an average labor rate
of $60 per work hour. Required parts will cost approximately $4,752 per
airplane. Based on these figures, the total cost impact of the
terminating modification will be $15,312 per airplane.
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), 40101, 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-3533 (44 FR
50033, August 27, 1979), and by adding a new airworthiness directive
(AD), amendment 39-9383, to read as follows:
95-20-05 Boeing: Amendment 39-9383. Docket 94-NM-255-AD. Supersedes
AD 79-17-07, Amendment 39-3533.
Applicability: Model 747 series airplanes, as listed in Boeing
Service Bulletin 747-54-2062, Revision 7, dated December 21, 1994;
certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise 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 use the authority
provided in paragraph (g) of this AD to request approval from the
FAA. This approval may address either no action, if the current
configuration eliminates the unsafe condition; or different actions
necessary to address the unsafe condition described in this AD. Such
a request should include an assessment of the effect of the changed
configuration on the unsafe condition addressed by this AD. In no
case does the presence of any modification, alteration, or repair
remove any airplane from the applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
To prevent failure of the strut and subsequent loss of an
engine, accomplish the following:
Note 2: Paragraph (a) of this AD restates the requirements for
initial and repetitive visual inspections contained in paragraphs
A., and C., respectively, of AD 79-17-07, amendment 39-3583.
Therefore, for operators who have previously accomplished at least
the initial inspection in accordance with AD 79-17-07, paragraph (a)
of this AD requires that the next scheduled inspection be performed
within the intervals specified in (a)(1) or (a)(2), as applicable,
after the last inspection performed in accordance with paragraph A.
or C. of AD 79-17-07.
(a) For airplanes listed in Boeing Service Bulletin 747-54-2062,
dated August 17, 1979: Prior to the accumulation of 5,000 total
landings on the airplane, or within 500 hours time-in-service after
September 4, 1979 (the effective date of AD 79-17-07, Amendment 39-
3533), whichever occurs later, perform a visual inspection of the
forward lower diagonal brace fittings of the inboard pylon
[[Page 51707]]
to detect cracking, in accordance with Boeing Service Bulletin 747-54-
2062, dated August 17, 1979, or Revision 7, dated December 21, 1994;
or in accordance with a method approved by the Manager, Seattle
Aircraft Certification Office, FAA, Transport Airplane Directorate.
After the effective date of this AD, only Revision 7 of the service
bulletin shall be used.
Note 3: Inspections performed prior to the effective date of
this AD are considered to be in compliance with paragraph (a) of
this AD if performed in accordance with Boeing Service Bulletin 747-
54-2062, August 17, 1979; Revision 1, dated November 13, 1980;
Revision 2, dated March 19, 1981; Revision 3, dated August 28, 1981;
Revision 4, dated June 30, 1982; Revision 5, dated June 1, 1984;
Revision 6, dated October 2, 1986, or Revision 7, dated December 21,
1994.
(1) If no cracking is detected, repeat the inspections at
intervals not to exceed 1,000 landings until all affected fittings
are replaced with steel fittings in accordance with Revision 7 of
the service bulletin.
(2) If any cracking is detected, prior to further flight,
accomplish either paragraph (a)(2)(i) or (a)(2)(ii) of this AD until
the inspections required by paragraph (b) of this AD are
accomplished.
(i) Repair or replace the cracked fitting in accordance with the
service bulletin; or
(ii) Rework the cracked fitting in accordance with the service
bulletin as required by paragraph (b) of this AD. Thereafter, repeat
the inspections at intervals not to exceed 250 landings until the
reworked fitting is replaced with a serviceable fitting, or until
the inspections required by paragraph (b) of this AD are
accomplished.
(b) For airplanes as listed in Boeing Service Bulletin 747-54-
2062, Revision 7, dated December 21, 1994: Perform a detailed visual
inspection and a surface high frequency eddy current (HFEC)
inspection to detect cracking of the inboard strut-to- diagonal
brace attach fittings, in accordance with Boeing Service Bulletin
747-54-2062, Revision 7, dated December 21, 1994, at the time
specified in either paragraph (b)(1) or (b)(2) of this AD, as
applicable.
(1) For airplanes on which a cracked fitting has been reworked
in accordance with Boeing Service Bulletin 747-54-2062, dated August
17, 1979: Perform the inspections within 250 landings since the last
inspection performed in accordance with paragraph (a)(2)(ii) of this
AD.
(2) For airplanes other than those identified in paragraph
(b)(1) of this AD: Perform the inspections at the earlier of the
times specified in paragraph (b)(2)(i) or (b)(2)(ii) of this AD.
(i) Prior to the accumulation of 5,000 total landings on the
airplane, or within 1,000 landings after the effective date of this
AD, whichever occurs later; or
(ii) Within 1,000 landings since the last inspection performed
in accordance with paragraph (a) of this AD.
(c) If no cracking is detected during the inspections required
by paragraph (b) of this AD, repeat the inspections thereafter at
intervals not to exceed 1,000 landings.
(d) If more than one crack is found during any inspection
required by this AD, or if any crack is detected that is beyond the
limits specified in Boeing Service Bulletin 747-54-2062, Revision 7,
dated December 21, 1994, prior to further flight, replace the attach
fitting with a steel fitting in accordance with the service
bulletin.
(e) If any transverse or longitudinal crack is found during the
inspection required by paragraph (b) of this AD, and that crack is
within the limits specified by Boeing Service Bulletin 747-54-2062,
Revision 7, dated December 21, 1994: Prior to further flight, stop
drill the crack in accordance with the service bulletin, and
accomplish the requirements of either paragraph (e)(1) or (e)(2) of
this AD, as applicable.
(1) For any transverse crack that is found, accomplish the
following:
(i) Prior to further flight, remove the affected fastener and
perform an open-hole HFEC inspection to detect cracking of the
fastener hole, in accordance with the service bulletin. Thereafter,
repeat this inspection within 125 landings.
(ii) Repeat the inspections required by paragraph (b) of this AD
within 125 landings after performing them initially.
(iii) If any crack is found during the inspections required by
this paragraph and the crack is beyond the limits specified in the
service bulletin, prior to further flight, replace the attach
fitting with a steel fitting in accordance with the service
bulletin.
(iv) Prior to the accumulation of 250 landings following the
detection of the transverse cracking, replace the attach fitting
with a steel fitting in accordance with the service bulletin.
(2) For any longitudinal crack that is found, accomplish the
following:
(i) Repeat the inspection required by paragraph (b) of this AD
at intervals not to exceed 250 landings.
(ii) Prior to the accumulation of 1,000 landings following
detection of the longitudinal cracking, replace the attach fitting
with a steel fitting in accordance with the service bulletin.
(f) Replacement of the attach fittings of the strut-to-diagonal
brace with steel fittings, in accordance with Boeing Service
Bulletin 747-54-2062, Revision 7, dated December 21, 1994,
constitutes terminating action for the requirements of this AD.
Note 4: Replacement of the attach fittings of the strut to
diagonal brace with steel fittings prior to the effective date of
this AD is considered in compliance with paragraph (f) of this AD if
performed in accordance with Boeing Service Bulletin 747-54-2062,
Revision 1, dated November 13, 1980; Revision 2, dated March 19,
1981; Revision 3, dated August 28, 1981; Revision 4, dated June 30,
1982; Revision 5, dated June 1, 1984; or Revision 6, dated October
2, 1986.
Note 5: This AD does not require certain additional work (to
seal a gap between the fitting and the existing closure web, or
replacement of the bushings in the diagonal brace fitting with anvil
swaged bushings) as described in Boeing Service Bulletin 747-54-
2062, Revision 7, dated December 21, 1994. However, these
installations are required to be accomplished as part of AD 95-10-
16, amendment 39-9233 (60 FR 27008, May 22, 1995). Table 2 of Boeing
Service Bulletin 747-54A2159, ``Prior or Concurrent Service
Bulletins'' (which is cited in AD 95-10-16), specifies that Boeing
Service Bulletin 747-54-2062, Revision 7, dated December 21, 1994
(which is cited in this AD), must be accomplished prior to or
concurrent with the installations required by AD 95-10-16.
(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 6: 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
(i) The actions shall be done in accordance with Boeing Service
Bulletin 747-54-2062, Revision 7, dated December 21, 1994. 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 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 November 2, 1995.
Issued in Renton, Washington, on September 21, 1995.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-23914 Filed 10-2-95; 8:45 am]
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