AD 2001-15-02

[Federal Register Volume 66, Number 140 (Friday, July 20, 2001)]
[Rules and Regulations]
[Pages 37884-37886]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-18138]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-330-AD; Amendment 39-12336; AD 2001-15-02]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes 
Powered By Pratt & Whitney JT9D-3 and -7 Series 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 and torque checks of the 
hanger fittings and strut forward bulkhead of the forward engine mount 
and adjacent support structure, and corrective actions, if necessary. 
The existing AD also provides for optional terminating action for the 
repetitive inspections and checks. This amendment requires certain new 
repetitive torque checks and the previously optional terminating 
action. The actions specified by this AD are intended to prevent loose 
fasteners and associated damage to the hanger fittings and bulkhead of 
the forward engine mount, which could result in separation of the 
engine from the airplane.

DATES: Effective August 24, 2001.
    The incorporation by reference of Boeing Alert Service Bulletin 
747-54A2203, dated August 31, 2000, as listed in the regulations, was 
approved previously by the Director of the Federal Register as of 
December 6, 2000 (65 FR 69862, November 21, 2000).

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 Anderson, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, 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 2000-23-16, 
amendment 39-11988 (65 FR 69862, November 21, 2000), which is 
applicable to certain Boeing Model 747 series airplanes, was published 
in the Federal Register on February 15, 2001 (66 FR 10387). The action 
proposed to continue to require repetitive inspections and torque 
checks of the hanger fittings and strut forward bulkhead of the forward 
engine mount and adjacent support structure, and corrective actions, if 
necessary. The action also proposed to mandate certain new repetitive 
torque checks and the previously optional 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 comments received.

Request to Eliminate Repetitive Inspections/Checks and Terminating 
Action

    One commenter states that, if the initial torque check shows no 
loose fastener is installed, the repetitive inspections/checks and 
terminating action should not be required. The commenter's rationale 
for this request is that the cause of the loose fasteners is incorrect 
grip length of fasteners installed during a strut and wing 
modification.
    The FAA infers that the commenter is stating that, if the fastener 
is not loose at the time of the initial inspection, it will not become 
loose later, and is requesting that we remove these requirements from 
this AD. The FAA does not concur. If the wrong grip-length of fastener 
is installed, damage of the fastener thread run-out may have occurred 
during initial installation of the fastener due to shanking of the 
fastener. This could lead to a problem with the durability of the 
fastener. No change to the final rule is necessary in this regard.

Reduce Torque Values for Loose Fastener Check

    One commenter requests that the FAA revise the proposed rule to 
reduce the torque values for the loose fastener check to the minimum 
value. As an example, the commenter refers to the torque value of 250 
inch-pounds for the NAS6706 fastener listed in Table 1 of Figure 3 of 
Boeing Alert Service Bulletin 747-54A2203, dated August 31, 2000. The 
commenter states that this value should be 220 inch-pounds because that 
is the minimum installation torque required.
    The FAA does not concur with the commenter's request. The 
difference in torque value to which the commenter refers is very small. 
If an operator determines that a fastener is NOT loose at a torque 
value of 220 inch-pounds but IS loose at a torque value of 250 inch-
pounds, the operator may apply for an alternative method of compliance 
according to the provisions of paragraph (d) of this AD. No change to 
the final rule is necessary in this regard.

Clarify Instructions for Torque Check

    One commenter requests that the FAA clarify how the torque check 
should be accomplished. The commenter specifically asks whether or not 
the fastener head should be retained if torque is applied to the nut 
end.
    The FAA does not concur that any further clarification on this 
issue is necessary. The applicable service bulletin specifies that the 
torque check is intended to test whether the fastener rotates. The 
fastener head should not be retained because, if it is retained, it may 
be impossible to determine whether the fastener rotated before reaching 
the specified torque in Figure 3 of the service bulletin. No change to 
the final rule is necessary in this regard.

Explanation of Change to Alternative Method of Compliance (AMOC) 
Paragraph

    Since the issuance of the proposed rule, the FAA has approved AMOCs 
for AD 2000-23-16. AMOCs approved previously in accordance with AD 
2000-23-16 are considered acceptable for compliance with corresponding 
actions in this AD. Accordingly, a new paragraph (d)(2) has been added 
to this final 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 with the change previously 
described. The FAA has determined that this change will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 366 Model 747 series airplanes of the 
affected design in the worldwide fleet. The FAA

[[Page 37885]]

estimates that 115 airplanes of U.S. registry will be affected by this 
AD.
    The detailed visual inspections that are currently required by AD 
2000-23-16 take approximately 8 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 inspections currently required by the existing 
AD on U.S. operators is estimated to be $55,200, or $480 per airplane, 
per inspection.
    The torque checks that are currently required by AD 2000-23-16 take 
approximately 24 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 torque checks currently required by the existing AD on 
U.S. operators is estimated to be $165,600, or $1,440 per airplane, per 
check.
    The new torque checks required by this AD also will take 
approximately 8 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of this torque check on U.S. operators is estimated to be 
$55,200, or $480 per airplane, per check.
    The terminating action required by this AD will take approximately 
24 work hours per airplane to accomplish, at an average labor rate of 
$60 per work hour. Required parts will cost approximately $300 per 
airplane. Based on these figures, the cost impact of the terminating 
action required by this AD on U.S. operators is estimated to be 
$200,100, or $1,740 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. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

Regulatory Impact

    The regulations adopted herein will not have a substantial direct 
effect 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, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    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 39-11988 (65 FR 
80301, December 21, 2000), and by adding a new airworthiness directive 
(AD), amendment 39-12336, to read as follows:

2001-15-02 Boeing: Amendment 39-12336. Docket 2000-NM-330-AD. 
Supersedes AD 2000-23-16, Amendment 39-11988.

    Applicability: Model 747 series airplanes, certificated in any 
category, as listed in Boeing Alert Service Bulletin 747-54A2203, 
dated August 31, 2000; except Model 747 series airplanes having 
serial numbers 21048 and 20887.

    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 (d)(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 loose fasteners and associated damage to the hanger 
fittings and strut forward bulkhead of the forward engine mount, 
which could result in separation of the engine from the airplane, 
accomplish the following:

Restatement of Requirements of AD 2000-23-16

Repetitive Inspections/Checks

    (a) Within 60 days after December 6, 2000 (the effective date of 
AD 2000-23-16, amendment 39-11988): Perform a detailed visual 
inspection and torque check as specified in Part 2 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
54A2203, dated August 31, 2000, to detect loose fasteners and 
associated damage to the hanger fittings and bulkhead of the forward 
engine mount, in accordance with Figure 1 of the alert service 
bulletin.

    Note 2: For the purposes of this AD, a detailed visual 
inspection is defined as: ``An intensive visual examination of a 
specific structural area, system, installation, or assembly to 
detect damage, failure, or irregularity. Available lighting is 
normally supplemented with a direct source of good lighting at 
intensity deemed appropriate by the inspector. Inspection aids such 
as mirror, magnifying lenses, etc., may be used. Surface cleaning 
and elaborate access procedures may be required.''

    (1) If no loose fastener or associated damage is detected, 
repeat the inspections/checks thereafter at the applicable intervals 
specified in Figure 1 of the alert service bulletin until 
accomplishment of the terminating action specified in paragraph (c) 
of this AD.

    Note 3: Where there are differences between the AD and the alert 
service bulletin, the AD prevails.

Corrective Actions

    (2) If any loose fastener or associated damage is detected, 
before further flight, perform the applicable corrective actions 
(torque check, rework or replacement of fittings), as specified in 
Figure 1 of the alert service bulletin. Repeat the inspections/
checks thereafter at the applicable intervals specified in Figure 1 
of the alert service bulletin until accomplishment of the 
terminating action specified in paragraph (c) of this AD. Where the 
alert service bulletin specifies that the manufacturer may be 
contacted for disposition of certain corrective actions (rework or 
replacement of fittings), this AD requires such rework and/or 
replacement to be done in accordance with a method approved by the 
Manager, Seattle Aircraft Certification Office (ACO), FAA; or in 
accordance with data meeting the type certification basis of the 
airplane approved by a Boeing Company designated engineering 
representative (DER) who has been authorized by the Manager, Seattle 
ACO, to make such findings. For a repair method to be approved by 
the Manager, Seattle ACO, as required by this paragraph, the 
Manager's approval letter must specifically reference this AD.

[[Page 37886]]

New Requirements of this AD

Repetitive Checks/ Inspections/Corrective Actions

    (b) Within 18 months after the effective date of this AD: Do the 
torque check specified in Part 3 of the Accomplishment Instructions 
of Boeing Alert Service Bulletin 747-54A2203, dated August 31, 2000, 
to detect loose fasteners of the hanger fittings of the forward 
engine mount.
    (1) If no loose fastener is detected, repeat the torque check 
thereafter at intervals not to exceed 1,200 flight cycles or 18 
months, whichever occurs first, until accomplishment of the 
terminating action specified in paragraph (c) of this AD.
    (2) If any loose fastener is detected, before further flight, 
perform the applicable corrective actions as specified in Figure 4, 
Figure 5, or Part 6, as applicable, of the Accomplishment 
Instructions of the alert service bulletin.
    (i) If Figure 4 or Figure 5 of the Accomplishment Instructions 
of the alert service bulletin is used to do the corrective actions 
for the fitting; thereafter, repeat the detailed visual inspection 
required by paragraph (a) of this AD at the applicable intervals 
specified in Figure 1 of the alert service bulletin, and repeat the 
torque check for that fitting at intervals not to exceed 180 flight 
cycles. Accomplish the terminating action for that fitting as 
specified in Part 6 of the Accomplishment Instructions of the alert 
service bulletin within 18 months after finding any loose fastener 
or 60 months after the effective date of this AD, whichever occurs 
first.
    (ii) If Part 6 of the Accomplishment Instructions of the alert 
service bulletin is used to do the corrective actions for the 
fitting, this constitutes terminating action for the repetitive 
inspections/checks for that fitting only.
    (3) If any associated damage is found, before further flight, 
repair in accordance with a method approved by the Manager, Seattle 
ACO, or in accordance with data meeting the type certification basis 
of the airplane approved by a Boeing Company DER who has been 
authorized by the Manager, Seattle ACO, to make such findings. For a 
repair method to be approved by the Manager, Seattle ACO, as 
required by this paragraph, the Manager's approval letter must 
specifically reference this AD. If any damage to any fitting is 
found, before further flight, do the applicable corrective actions 
specified in Part 4 or Part 5 of the Accomplishment Instructions of 
the alert service bulletin; this constitutes terminating action for 
the repetitive inspections/checks for that fitting only.
    (4) If any loose fastener is detected during any repeat 
inspection/check specified in paragraph (b)(2)(i) of this AD, before 
further flight, accomplish the terminating action for that fitting 
as specified in Part 6 of the Accomplishment Instructions of the 
alert service bulletin.

Terminating Action

    (c) Within 60 months after the effective date of this AD: 
Accomplish all actions in the terminating action specified in Part 6 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-54A2203, dated August 31, 2000. Accomplishment of this paragraph 
constitutes terminating action for the repetitive inspections/checks 
required by paragraphs (a) and (b) of this AD. Where the alert 
service bulletin specifies that the manufacturer may be contacted 
for disposition of certain corrective actions (rework or replacement 
of fittings), this AD requires such rework and/or replacement to be 
done in accordance with a method approved by the Manager, Seattle 
ACO; or in accordance with data meeting the type certification basis 
of the airplane approved by a Boeing Company DER who has been 
authorized by the Manager, Seattle ACO, to make such findings. For a 
repair method to be approved by the Manager, Seattle ACO, as 
required by this paragraph, the Manager's approval letter must 
specifically reference this AD.

    Note 4: Installation of two BACW10BP*APU washers on Group A 
fasteners accomplished during modification in accordance with Boeing 
Service Bulletin 747-54A2159, dated November 3, 1994, Revision 1, 
dated June 1, 1995, or Revision 2, dated March 14, 1996; and pin or 
bolt protrusion as specified in the 747 Structural Repair Manual, 
Chapter 51-30-02 (both referenced in Boeing Alert Service Bulletin 
747-54A2203, dated August 31, 2000); is considered acceptable for 
compliance with the terminating action specified in paragraph (c) of 
this AD.

Alternative Methods of Compliance

    (d)(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 ACO. 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.
    (2) Alternative methods of compliance, approved previously in 
accordance with AD 2000-23-16, amendment 39-11988, are approved as 
alternative methods of compliance for corresponding actions in this 
AD.

    Note 5: 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

    (e) 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.

Incorporation by Reference

    (f) Except as provided by paragraph (a)(2), (b)(3), and (c) of 
this AD, the actions shall be done in accordance with Boeing Alert 
Service Bulletin 747-54A2203, dated August 31, 2000. The 
incorporation by reference of that document was approved previously 
by the Director of the Federal Register as of December 6, 2000 (65 
FR 69862, November 21, 2000). 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.

Effective Date

    (g) This amendment becomes effective on August 24, 2001.

    Issued in Renton, Washington, on July 13, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-18138 Filed 7-19-01; 8:45 am]
BILLING CODE 4910-13-P