[Federal Register Volume 64, Number 191 (Monday, October 4, 1999)]
[Rules and Regulations]
[Pages 53621-53623]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-25218]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-277-AD; Amendment 39-11339; AD 99-20-09]
RIN 2120-AA64


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 inspections of the lower engine mount to determine 
if the tangential link upper bolt and nut are oriented properly, and if 
the tangential link upper bolt nut is torqued within certain limits. 
Additionally, that amendment requires replacement of the bolt and nut 
with serviceable parts, if necessary, and requires certain follow-on 
actions for airplanes on which the upper bolt is missing. This 
amendment requires accomplishment of a previously optional terminating 
action or a new alternative terminating action for the repetitive 
inspections. This amendment is prompted by development of a new 
terminating action by the manufacturer. The actions specified by this 
AD are intended to prevent separation of the engine from the airplane 
due to migration of the tangential link upper bolt.

DATES: Effective November 8, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 8, 1999.
    The incorporation by reference of Boeing Alert Service Bulletin 
747-71A2277, dated November 29, 1995, listed in the regulations, was 
approved previously by the Director of the Federal Register as of 
February 16, 1996 (61 FR 10270, March 13, 1996).

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 96-03-01 R1, 
amendment 39-9538 (61 FR 10270, March 13, 1996), which is applicable to 
certain Boeing Model 747 series airplanes, was published in the Federal 
Register on July 16, 1999 (64 FR 38379). The action proposed to 
continue to require inspections of the lower engine mount to determine 
if the tangential link upper bolt and nut are oriented properly, and if 
the tangential link upper bolt nut is torqued within certain limits. 
Additionally, that action also proposed to continue to require 
replacement of the bolt and nut with serviceable parts, if necessary, 
and requires certain follow-on actions for airplanes on which the upper 
bolt is missing. That action also proposed to require accomplishment of 
either a previously optional terminating action or a new, alternative 
terminating action for the repetitive 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 421 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 185 airplanes of U.S. registry 
will be affected by this AD.
    The inspections that are currently required by AD 96-03-01 R1 take 
approximately 16 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 actions on U.S. operators is estimated 
to be $177,600, or $960 per airplane, per inspection cycle.
    The replacement of the safety link that is required as one option 
for compliance with this AD action will take approximately 18 work 
hours per airplane to accomplish, at an average

[[Page 53622]]

labor rate of $60 per work hour. Required parts will cost approximately 
$30,228 per airplane. Based on these figures, the cost impact of this 
replacement required by this AD on U.S. operators is estimated to be 
$31,308 per airplane.
    In lieu of replacement of the safety link, this AD provides for 
replacement of the tangential link upper bolt on the aft engine mount 
with a reworked bolt and a new nut retainer. Such replacement, which is 
provided as an additional option for compliance with this AD action, 
will take approximately 20 work hours per airplane to accomplish, at an 
average labor rate of $60 per work hour. Required parts will cost 
approximately $1,888 per airplane. Based on these figures, the cost 
impact of this replacement required by this AD on U.S. operators is 
estimated to be $3,088 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.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-9538 (61 FR 
10270, March 13, 1996), and by adding a new airworthiness directive 
(AD), amendment 39-11339, to read as follows:

99-20-09 Boeing: Amendment 39-11339. Docket 98-NM-277-AD. Supersedes 
AD 96-03-01 R1, amendment 39-9538.

    Applicability: Model 747 series airplanes, as listed in Boeing 
Alert Service Bulletin 747-71A2277, dated November 29, 1995; or 
Boeing Service Bulletin 747-71A2277, Revision 1, dated May 21, 1998, 
or Revision 2, dated January 14, 1999; 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 (c)(1) 
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 separation of the engine from the airplane, 
accomplish the following:

Restatement of Requirements of AD 96-03-01 R1, Amendment 39-9538

Inspections and Corrective Actions

    (a) Within 90 days after February 16, 1996 (the effective date 
of AD 96-03-01 R1, amendment 39-9538), accomplish the requirements 
of paragraphs (a)(1) and (a)(2) of this AD in accordance with Boeing 
Alert Service Bulletin 747-71A2277, dated November 29, 1995, or 
Boeing Service Bulletin 747-71A2277, Revision 1, dated May 21, 1998, 
or Revision 2, dated January 14, 1999.
    (1) Perform a visual inspection to ensure that installation of 
the tangential link upper bolt nut is on the forward side of the 
engine mount fitting.
    (i) If the tangential link upper bolt nut is installed on the 
forward side of the engine mount fitting, repeat the visual 
inspection at intervals not to exceed 18 months.
    (ii) If the tangential link upper bolt nut is not installed on 
the forward side of the engine mount fitting, prior to further 
flight, remove the nut, bolt, and washers, and reinstall the nut, 
bolt, and washers in accordance with the service bulletin. 
Thereafter, repeat the visual inspection at intervals not to exceed 
18 months.
    (iii) If the tangential link upper bolt is missing from the 
engine mount fitting, prior to further flight, perform the various 
follow-on actions in accordance with the service bulletin. (The 
follow-on actions include visual inspections, magnetic particle 
inspections, replacement of the lower engine mount fitting with a 
serviceable part, if necessary; installation of new safety links, 
bolts, and nuts; and installation of a new tangential link upper 
bolt.) Thereafter, repeat the visual inspection at intervals not to 
exceed 18 months.
    (2) Perform an inspection to verify that the torque value of the 
tangential link upper bolt (on both sides of the mount) is within 
the limits specified in the service bulletin.
    (i) If the torque value of the tangential link upper bolt nut is 
within the limits specified in the service bulletin, repeat the 
inspection (verification) at intervals not to exceed 18 months.
    (ii) If the torque value of the tangential link upper bolt nut 
is outside the limits specified in the service bulletin, prior to 
further flight, perform a visual inspection of the tangential link 
upper bolt and washer for any damage or discrepancy, in accordance 
with the service bulletin.
    (A) If no damage or discrepancy of the tangential link upper 
bolt and washers is found, prior to further flight, replace the bolt 
nut with a new or serviceable part in accordance with the service 
bulletin. Thereafter, repeat the inspection (verification) specified 
in paragraph (a)(2) of this AD at intervals not to exceed 18 months.
    (B) If any damage or discrepancy of the tangential link upper 
bolt and washers is found, prior to further flight, replace the 
damaged or discrepant part with a new or serviceable part, and 
replace the bolt nut with a new or serviceable part, in accordance 
with the service bulletin. Thereafter, repeat the inspection 
(verification) specified in paragraph (a)(2) of this AD at intervals 
not to exceed 18 months.

New Requirements of This AD

Replacement

    (b) Within 18 months after the effective date of this AD, 
accomplish the requirements of either paragraph (b)(1) or (b)(2) of 
this AD. Accomplishment of either paragraph (b)(1) or (b)(2) of this 
AD constitutes terminating action for the repetitive inspection 
requirements of this AD.
    (1) Replace the safety links on the aft engine mount with 
modified safety links in accordance with Boeing Service Bulletin 
747-71-2206, dated April 16, 1987; or Boeing Service Bulletin 747-
71-2206, Revision 1, dated November 12, 1987, as revised by Boeing 
Notice of Status Change No. 747-71-2206 NSC 1, dated December 4, 
1987, and Boeing Notice of Status Change

[[Page 53623]]

No. 747-71-2206 NSC 2, dated March 17, 1988.
    (2) Replace the tangential link upper bolt on the aft engine 
mount with a reworked bolt and a new nut retainer, in accordance 
with Parts 2 and 3 of Boeing Service Bulletin 747-71A2277, Revision 
1, dated May 21, 1998, or Revision 2, dated January 14, 1999.

Alternative Methods of Compliance

    (c)(1) 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.
    (c)(2) Alternative methods of compliance, approved previously in 
accordance with AD 96-03-01 R1, amendment 39-9538, are approved as 
alternative methods of compliance with this AD.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (d) Special flight permits may be issued in accordance with 
Secs. 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.

Incorporation by Reference

    (e) The actions shall be done in accordance with Boeing Alert 
Service Bulletin 747-71A2277, dated November 29, 1995; Boeing 
Service Bulletin 747-71A2277, Revision 1, dated May 21, 1998; Boeing 
Service Bulletin 747-71A2277, Revision 2, dated January 14, 1999; 
Boeing Service Bulletin 747-71-2206, dated April 16, 1987; or Boeing 
Service Bulletin 747-71-2206, Revision 1, dated November 12, 1987, 
as revised by Boeing Notice of Status Change No. 747-71-2206 NSC 1, 
dated December 4, 1987, and Boeing Notice of Status Change No. 747-
71-2206 NSC 2, dated March 17, 1988; as applicable.
    (1) The incorporation by reference of Boeing Service Bulletin 
747-71A2277, Revision 2, dated January 14, 1999; Boeing Service 
Bulletin 747-71-2206, dated April 16, 1987; or Boeing Service 
Bulletin 747-71-2206, Revision 1, dated November 12, 1987, as 
revised by Boeing Notice of Status Change No. 747-71-2206 NSC 1, 
dated December 4, 1987, and Boeing Notice of Status Change No. 747-
71-2206 NSC 2, dated March 17, 1988; as applicable is approved by 
the Director of the Federal Register in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51. Boeing Service Bulletin 747-71-2206, 
Revision 1, dated November 12, 1987, contains the following list of 
effective pages:

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                               Revision level
          Page No.             shown on page       Date shown on page
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1-5, 9, 10, 12..............  1..............  November 12, 1987.
6-8, 11, 13-18..............  Original.......  April 16, 1987.
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    (2) The incorporation by reference of Boeing Alert Service 
Bulletin 747-71A2277, dated November 29, 1995, was approved 
previously by the Director of the Federal Register as of February 
16, 1996 (61 FR 10270, March 13, 1996).
    (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.
    (f) This amendment becomes effective on November 8, 1999.

    Issued in Renton, Washington, on September 22, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-25218 Filed 10-1-99; 8:45 am]
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