AD 2001-05-05

[Federal Register Volume 66, Number 44 (Tuesday, March 6, 2001)]
[Rules and Regulations]
[Pages 13424-13426]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-5168]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-01-AD; Amendment 39-12141; AD 2001-05-05]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

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 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 action also 
provides for an optional terminating modification for the repetitive 
inspections. This action is necessary 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. This action is intended to address the identified unsafe 
condition.

DATES: Effective March 21, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 21, 2001.
    Comments for inclusion in the Rules Docket must be received on or 
before May 7, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-01-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#b58c98d4dbd898dcd4c7d6dad8d8d0dbc1f5d3d4d49bd2dac3"><span class="__cf_email__" data-cfemail="665f4b07080b4b0f071405090b0b0308122600070748010910">[email&#160;protected]</span></a>. Comments sent via fax or the Internet must 
contain ``Docket No. 2001-NM-01-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 several reports 
indicating that, during routine maintenance, loose primary retention 
nuts of the midspar fuse pins of the inboard and outboard struts were 
found on certain Boeing Model 747 series airplanes. One report 
indicated that the primary retention nut migrated into the secondary 
retention washer. The cause of these discrepancies was determined to be 
inadequate run-on torque of the primary retention nut. Such conditions, 
if not fixed, could result in the loss of secondary retention 
capabilities of the fuse pins, migration of the fuse pins, reduction of 
the joint capability of the midspar fittings to carry the design loads, 
and consequent loss of the strut and engine from the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 747-
54A2206, Revision 1, dated February 22, 2001, which describes 
procedures for repetitive detailed visual inspections to find 
discrepancies (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, and follow-on actions, if necessary.
    If the primary nut has backed off and is contacting the secondary 
retention washer; the follow-on actions include, but are not limited 
to:

<bullet> Inspection of the fuse pin threads for damage,
<bullet> Installation of a new primary nut,
<bullet> Replacement of damaged fuse pins with new pins, and
<bullet> Installation of a torque stripe.

    If the primary nut has backed off and is not contacting the 
secondary retention washer, follow-on actions consist of repeating the 
inspection of the fuse pin installation at a reduced inspection 
interval.
    The service bulletin also provides for an optional terminating 
modification which consists of replacement of the primary nut of the 
midspar fuse pin with a new nut and installation of the torque stripe, 
a detailed visual inspection of the fuse pin threads for damage, and 
replacement of the fuse pin, if necessary, Doing these actions ends the 
repetitive inspections.

Other Relevant Rulemaking

    This AD is related to AD 95-10-16, amendment 39-9233 (60 FR 27008, 
May 22, 1995); AD 95-13-05, amendment 39-9285 (60 FR 33333, June 28, 
1995); AD 95-13-06, amendment 39-9286 (60 FR 33338, June 28, 1995); AD 
95-13-07, amendment 39-9287 (60 FR 33336, June 28, 1995), and AD 99-10-
10, amendment 39-11163 (64 FR 25197, May 11, 1999). The replacement of 
fuse pins in the upper link, midspar fittings, and diagonal brace of 
the nacelle strut with new corrosion-resistant pins is required by 
those AD's as part of the modification of the nacelle strut/wing 
structure for earlier Model 747 series airplanes. The actions required 
by this AD are to be done if any of the AD's specified above, or the 
production equivalent, has been accomplished.

[[Page 13425]]

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, this AD 
requires accomplishment of the actions specified in the service 
bulletin described previously.

Interim Action

    This is considered to be interim action. The FAA is currently 
considering requiring the optional terminating modification, which will 
constitute terminating action for the repetitive inspections required 
by this AD action. However, the planned compliance time for the 
installation of the modification is sufficiently long so that notice 
and opportunity for prior public comment will be practicable.

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 2001-NM-01-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 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:

2001-05-05  Boeing: Amendment 39-12141. Docket 2001-NM-01-AD.

    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 per 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:

Inspections/Follow-On Actions

    (a) At the latest of the times specified in paragraphs (a)(1) 
and (a)(2) of this AD, as applicable: Do a detailed visual 
inspection to find discrepancies (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 not 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)(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 the effective date of this AD.
    (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

[[Page 13426]]

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 95-16-16................................................      39-9233
AD 95-13-05................................................      39-9285
AD 95-13-06................................................      39-9286
AD 95-07...................................................      39-9287
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 the effective date of this AD.

    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 the effective date of this AD, whichever occurs later, 
do the terminating modification specified in paragraph (b) of this 
AD.

    Note 4: Inspections accomplished 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.

Optional Terminating Action

    (b) Doing 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, 
ends the repetitive inspections required by this AD.

    Note 5: Accomplishment of the terminating action specified in 
Boeing Alert Service Bulletin 747-54A2206, dated October 19, 2000, 
is 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 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 per 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) The actions shall be done per Boeing Service Bulletin 747-
54A2206, Revision 1, dated February 22, 2001. This incorporation by 
reference was approved by the Director of the Federal Register per 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 March 21, 2001.

    Issued in Renton, Washington, on February 26, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-5168 Filed 3-5-01; 8:45 am]
BILLING CODE 4910-13-P