[Federal Register Volume 66, Number 81 (Thursday, April 26, 2001)]
[Proposed Rules]
[Pages 20950-20952]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-10344]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-02-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain Boeing Model 747 
series airplanes, that currently requires repetitive detailed visual 
inspections to find discrepancies of the installation of the midspar 
fuse pins of the inboard and outboard struts, and follow-on actions, if 
necessary. The existing AD also provides an optional terminating 
modification for the repetitive inspections. This action would mandate 
accomplishment of the previously optional terminating modification. The 
actions specified by the proposed AD are intended to find and fix 
discrepancies of the installation of the midspar fuse pins, which could 
result in loss of the secondary retention capability of the fuse pins, 
migration of the fuse pins, and consequent loss of the strut and engine 
from the airplane.

DATES: Comments must be received by June 11, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-02-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 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: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2001-NM-02-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 the proposed rule 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

[[Page 20951]]

Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

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:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Submit comments using the following format:
     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.
     For each issue, state what specific change to the proposed 
AD is being requested.
     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 proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NM-02-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 2001-NM-02-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On February 26, 2001, the FAA issued AD 2001-05-05, amendment 39-
12141 (66 FR 13424, March 6, 2001), applicable to certain Boeing Model 
747 series airplanes, to require repetitive detailed visual inspections 
to find discrepancies of the installation of the midspar fuse pins of 
the inboard and outboard struts, and follow-on actions, if necessary. 
That action also provides for an optional terminating modification for 
the repetitive inspections. The requirements of that AD are intended to 
find and fix discrepancies of the installation of the midspar fuse 
pins, which could result in loss of the secondary retention capability 
of the fuse pins, migration of the fuse pins, and consequent loss of 
the strut and engine from the airplane.

Actions Since Issuance of Previous Rule

    In the preamble to AD 2001-05-05, the FAA specified that the 
actions required by that AD were considered ``interim action'' and that 
we were considering requiring the optional terminating modification, 
which would constitute terminating action for the repetitive 
inspections required by that AD. The FAA has now determined that it is 
necessary to mandate the terminating modification, and this proposed AD 
follows from that determination.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would supersede AD 2001-05-05 to continue to require 
repetitive detailed visual inspections to find discrepancies of the 
installation of the midspar fuse pins of the inboard and outboard 
struts, and follow-on actions, if necessary. This proposed AD also 
would mandate the previously optional terminating modification, which 
would end the repetitive inspections. The actions would be required to 
be done per the service bulletin referenced in the existing AD.

Cost Impact

    There are approximately 1,111 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 256 airplanes of U.S. 
registry would be affected by this proposed AD.
    The inspections that are currently required by AD 2001-05-05 take 
approximately 4 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 inspections on U.S. operators is 
estimated to be $61,440, or $240 per airplane, per inspection cycle.
    The terminating modification that is proposed in this AD action 
would take approximately 4 work hours per airplane to accomplish, at an 
average labor rate of $60 per work hour. Required parts would cost 
approximately $1,000 per airplane. Based on these figures, the cost 
impact of the modification proposed by this AD on U.S. operators is 
estimated to be $317,440, or $1,240 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the current or proposed 
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 proposed herein would 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 proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation

[[Page 20952]]

Administration proposes to amend 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 39-12141 (66 FR 
13424, March 6, 2001), and by adding a new airworthiness directive 
(AD), to read as follows:

Boeing: Docket 2001-NM-02-AD. Supersedes AD 2001-05-05, amendment 
39-12141.

    Applicability: Model 747 series airplanes, as listed in Boeing 
Service Bulletin 747-54A2206, Revision 1, dated February 22, 2001, 
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) 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 find and fix discrepancies of the installation of the midspar 
fuse pins of the inboard and outboard strut, which could result in 
loss of the secondary retention capability of the fuse pins, 
migration of the fuse pins, and consequent loss of the strut and 
engine from the airplane; accomplish the following:

Restatement of the Requirements of AD 2001-05-05

Inspections/Follow-On Actions

    (a) At the time specified in paragraph (a)(1) or (a)(2) of this 
AD, as applicable: Do a detailed visual inspection to find 
discrepancies (e.g., incorrect thread protrusion, which is less than 
two threads protruding from the nut between the nut and the 
secondary retention washer; incorrect gap between the fuse pin 
primary nut and secondary retention washer; cracked or broken torque 
stripe) of the installation of the midspar fuse pins of the inboard 
and outboard struts, per Figure 2 of Boeing Service Bulletin 747-
54A2206, Revision 1, dated February 22, 2001.
    (1) For airplanes modified per the production equivalent of one 
of the AD's listed in Table 1 of this AD: Do the inspection at the 
later of the times specified in paragraphs (a)(1)(i) and (a)(1)(ii) 
of this AD.
    (i) Before the accumulation of 8,000 total flight hours, or 
within 24 months since manufacture of the airplane, whichever occurs 
first.
    (ii) Within 90 days after March 21, 2001 (the effective date of 
AD 2001-05-05, amendment 39-12141).
    (2) For airplanes modified per one of the AD's listed in Table 1 
of this AD: Do the inspection at the later of the times specified in 
paragraphs (a)(2)(i) and (a)(2)(ii) of this AD. Table 1 follows:

                                 Table 1
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                                                              Amendment
                          AD No.                                 No.
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AD 95-10-16...............................................  39-9233
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AD 95-13-05...............................................  39-9285
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AD 95-13-06...............................................  39-9286
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AD 95-13-07...............................................  39-9287
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AD 99-10-10...............................................  39-11163
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    (i) Within 8,000 flight hours, or within 24 months since doing 
the modification, whichever occurs first.
    (ii) Within 90 days after March 21, 2001.

    Note 2: Where there are differences between the AD and the 
service bulletin, the AD prevails.


    Note 3: 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.''

    (A) If no discrepancy is found: Repeat the inspection at 
intervals not to exceed 8,000 flight hours or 24 months, whichever 
is first, until you do the terminating modification specified in 
paragraph (b) of this AD.
    (B) If any discrepancy is found, and the primary nut has backed 
off and contacts the secondary retention washer: Before further 
flight, do the terminating modification specified in paragraph (b) 
of this AD.
    (C) If any discrepancy is found, and the primary nut does not 
contact the secondary retention washer: Repeat the inspection at 
intervals not to exceed 90 days. Within 18 months after the initial 
finding, or March 21, 2001, whichever occurs later, do the 
terminating modification specified in paragraph (b) of this AD.

    Note 4: Inspections done prior to the effective date of this AD 
per Boeing Alert Service Bulletin 747-54A2206, dated October 19, 
2000, are acceptable for compliance with the inspections required by 
paragraph (a) of this AD.

New Requirements of This AD

Terminating Action

    (b) Within 6 years after the effective date of this AD: Do the 
terminating modification (replacement of the primary nut of the 
midspar fuse pin with a new nut, installation of torque stripe, a 
detailed visual inspection of the fuse pin threads for damage, and 
replacement, if necessary) per Figure 3 of Boeing Service Bulletin 
747-54A2206, Revision 1, dated February 22, 2001. Doing this 
modification ends the repetitive inspections required by this AD.

    Note 5: Doing the terminating modification prior to the 
effective date of this AD per Boeing Alert Service Bulletin 747-
54A2206, dated October 19, 2000, is acceptable for compliance with 
the terminating action required by 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 Aircraft Certification 
Office (ACO), FAA. 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.

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.

    Issued in Renton, Washington, on April 19, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-10344 Filed 4-25-01 8:45 am]
BILLING CODE 4910-13-U