[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]
BILLING CODE 4910-13-U