AD 2000-23-16

[Federal Register Volume 65, Number 225 (Tuesday, November 21, 2000)]
[Rules and Regulations]
[Pages 69862-69865]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 00-29215]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-329-AD; Amendment 39-11988; AD 2000-23-16]
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; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Boeing Model 747 series airplanes. This action 
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. This 
action also provides for optional terminating action for the repetitive 
inspections and checks. This action is necessary to detect and correct 
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 December 6, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 6, 2000.
    Comments for inclusion in the Rules Docket must be received on or 
before January 22, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-329-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
<a href="/cdn-cgi/l/email-protection#4d74602c232060242c3f2e2220202823390d2b2c2c632a223b"><span class="__cf_email__" data-cfemail="90a9bdf1fefdbdf9f1e2f3fffdfdf5fee4d0f6f1f1bef7ffe6">[email&#160;protected]</span></a>. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-329-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    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 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.

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: The FAA has received reports indicating the 
detection of loose fasteners of the hanger fittings and strut forward 
bulkhead of the forward engine mount. In one occurrence, damage to a 
hanger fitting also was detected. Such damage has been attributed to 
loose fasteners of the front spar bulkhead of the strut. The fasteners 
may not have been fully torqued, or the nuts may have bottomed out on 
the bolt threads prior to full clamp-up during fastener torque.

[[Page 69863]]

Certain tolerance build-up conditions also could cause the nuts to 
shank during installation. These conditions, if not corrected, could 
result in loose fasteners and associated damage to the hanger fittings 
and bulkhead of the forward engine mount, and consequent separation of 
the engine from the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
747-54A2203, dated August 31, 2000, which describes procedures for 
repetitive detailed visual inspections and torque checks of the hanger 
fittings and strut forward bulkhead of the forward engine mount and 
adjacent support structure to detect loose fasteners, cracking, and/or 
damage; and corrective actions, if necessary. The corrective actions 
consist of a torque check, before further flight, if any loose 
fasteners are detected; rework of loose hanger fittings, and damaged or 
cracked fittings that are within the allowable rework limits; and 
replacement if damage or cracks are detected that are outside the 
allowable rework limits.
    If certain damage of the strut forward bulkhead; bulkhead chords; 
lower spar web; or bulkhead channel is detected, the alert service 
bulletin specifies contacting Boeing for rework/replacement 
instructions. The alert service bulletin also describes procedures for 
rework or replacement of the fittings, which eliminates the need for 
the repetitive inspections and checks. The alert service bulletin 
references Boeing Service Bulletin 747-54A2159, dated November 3, 1994; 
Revision 1, dated June 1, 1995; or Revision 2, dated March 14, 1996; 
and the 747 Structural Repair Manual, Chapter 51-30-02, as additional 
sources of service information for accomplishment of the terminating 
action.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, this AD is 
being issued to detect and correct 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. This 
AD requires repetitive inspections and torque checks of the hanger 
fittings and strut forward bulkhead of the forward engine mount and 
adjacent support structure to detect loose fasteners, cracking, and/or 
damage; and corrective actions, if necessary. This action also provides 
for optional terminating action for the repetitive inspections and 
checks. The actions are required to be accomplished in accordance with 
the alert service bulletin described previously, except as discussed 
below.

Interim Action

    This is considered to be interim action. At this time the FAA is 
considering a separate rulemaking action to mandate accomplishment of 
the terminating action described in Part 6 of the alert service 
bulletin, which would terminate the repetitive inspections and checks 
required by this AD action. The FAA also is considering mandating the 
torque checks described in Part 3 of the alert service bulletin, which 
would extend the repetitive inspection and check interval, until 
accomplishment of the terminating action. However, the planned 
compliance time for these actions is sufficiently long so that notice 
and opportunity for prior public comment will be practicable.

Differences Between Alert Service Bulletin and This AD

    Operators should note that, although the effectivity section of the 
alert service bulletin includes Boeing Model 747 series airplanes 
having serial numbers 21048 and 20887, these airplanes have been 
modified and are now powered by General Electric CF6-50 series engines, 
and are not affected by the actions required by this proposed rule.
    Operators also should note that, although the alert service 
bulletin specifies that the manufacturer may be contacted for certain 
rework and/or replacement instructions, this AD requires such rework 
and/or replacement to be done in accordance with a method approved by 
the FAA, or in accordance with data meeting the type certification 
basis of the airplane approved by a Boeing Company Designated 
Engineering Representative who has been authorized by the FAA to make 
such findings.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications shall identify the Rules Docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Submit comments using the following format:
    <bullet> Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    <bullet> For each issue, state what specific change to the AD is 
being requested.
    <bullet> Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-329-AD.'' The postcard will be date stamped 
and returned to the commenter.

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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to

[[Page 69864]]

correct an unsafe condition in aircraft, and that it is not a 
``significant regulatory action'' under Executive Order 12866. It has 
been determined further that this action involves an emergency 
regulation under DOT Regulatory Policies and Procedures (44 FR 11034, 
February 26, 1979). If it is determined that this emergency regulation 
otherwise would be significant under DOT Regulatory Policies and 
Procedures, a final regulatory evaluation will be prepared and placed 
in the Rules Docket.
    A copy of it, if filed, 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 adding the following new 
airworthiness directive:

2000-23-16  Boeing: Amendment 39-11988. Docket 2000-NM-329-AD.

    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 (c) 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 detect and correct 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:

Repetitive Inspections/Checks

    (a) Within 60 days after the effective date of this AD: Perform 
a detailed visual inspection and torque check as specified in Part 2 
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. Repeat the inspections/
checks thereafter at the applicable intervals specified in 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.''

Corrective Actions

    (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 (b) 
of this AD.

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

    (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 (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 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.

Optional Terminating Action

    (b) Accomplishment of the terminating action specified in Part 6 
of Boeing Alert Service Bulletin 747-54A2203, dated August 31, 2000, 
constitutes terminating action for the repetitive inspections/checks 
required by paragraph (a) of this AD.

    Note 4: Installation of two BACW10BP* auxiliary power unit 
washers on Group A fasteners accomplished prior to the effective 
date of this AD 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 (b) of this AD.

Alternative Methods of Compliance

    (c) 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.

    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

    (d) 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

    (e) Except as provided by paragraph (a)(2) of this AD, the 
actions shall be done in accordance with Boeing Alert Service 
Bulletin 747-54A2203, dated August 31, 2000. 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.

Effective Date

    (f) This amendment becomes effective on December 6, 2000.


[[Page 69865]]


    Issued in Renton, Washington, on November 8, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-29215 Filed 11-20-00; 8:45 am]
BILLING CODE 4910-13-U