[Federal Register Volume 67, Number 229 (Wednesday, November 27, 2002)]
[Proposed Rules]
[Pages 70875-70877]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-30027]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-23-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-200B and -200F Series 
Airplanes Powered by Pratt & Whitney JT9D-70 Series Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 747-200B and 
-200F series airplanes powered by Pratt & Whitney JT9D-70 series 
engines. This proposal would require repetitive detailed inspections of 
the pylon skin and internal structure of the nacelle struts adjacent to 
and aft of the precooler exhaust vent for heat damage (discoloration), 
wrinkling, and cracking; and corrective action, if necessary. This 
action is necessary to find and fix such damage, which could result in 
cracking

[[Page 70876]]

or fracture of the nacelle struts, and consequent reduced structural 
integrity and possible separation of the strut and engine from the 
airplane. This action is intended to address the identified unsafe 
condition.

DATES: Comments must be received by January 13, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-23-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: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2002-NM-23-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 Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Tamara L. 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:
    [sbull] 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.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] 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 2002-NM-23-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. 2002-NM-23-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports from three operators who found heat 
damage (discoloration) and cracking adjacent to and aft of the 
precooler exhaust vent on the nacelle struts of three Boeing Model 747 
series airplanes powered by Pratt & Whitney JT9D-70 series engines. 
Investigation revealed that high temperature exhaust air from the 
precooler vent caused the heat damage. Such damage to the structure 
could result in cracking or fracture of the nacelle struts, and 
consequent reduced structural integrity and possible separation of the 
strut and engine from the airplane.

Explanation of Relevant Service Information

    We have reviewed and approved Boeing Special Attention Service 
Bulletin 747-54-2210, dated December 19, 2001, which describes 
procedures for repetitive detailed inspections of the pylon skin and 
internal structure of the nacelle struts adjacent to and aft of the 
precooler exhaust vent for heat discoloration, wrinkling, and cracking; 
and corrective action, if necessary. The corrective action includes the 
following:
    [sbull] If heat discoloration but no wrinkling is found, do a 
conductivity test of the damaged area(s). If the conductivity test is 
within specified limits, do a penetrant or high frequency eddy current 
(HFEC) inspection of the heat discolored areas for cracking. If no 
cracking is found, repeat the detailed inspection.
    [sbull] If wrinkling is found, do a penetrant inspection for 
cracking of the wrinkled area(s). An optional HFEC inspection can also 
be done for such damage. The service bulletin specifies contacting the 
manufacturer for additional instructions if wrinkling is found.
    [sbull] If cracking is found, or the conductivity readings are not 
within the limits specified in the service bulletin, the service 
bulletin specifies contacting the manufacturer for additional 
instructions.
    Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the identified unsafe condition.

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 require accomplishment of the actions specified in 
the service bulletin described previously, except as discussed below.

Difference Between Proposed Rule and Service Bulletin

    Although the service bulletin specifies that the manufacturer may 
be contacted for disposition of certain repair conditions, this 
proposal would require the repair of those conditions to be 
accomplished per a method approved by the FAA, or per 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.

Cost Impact

    There are approximately 7 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 6 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take approximately 
8 work hours per airplane to accomplish the proposed inspection, and 
that the average labor rate is $60 per work hour. Based on these 
figures, the cost impact of the proposed AD on U.S. operators is 
estimated to be $2,880, or $480 per airplane, per inspection cycle.
    The cost impact figure discussed above is based on assumptions that 
no

[[Page 70877]]

operator has yet accomplished any of the proposed requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this proposed 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 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 adding the following new 
airworthiness directive:

    Boeing: Docket 2002-NM-23-AD.
    Applicability: Model 747-200B and -200F series airplanes powered 
by Pratt & Whitney JT9D-70 series engines, certificated in any 
category; as listed in Boeing Special Attention Service Bulletin 
747-54-2210, dated December 19, 2001.

    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 heat damage of the pylon skin and internal 
structure of the nacelle struts, which could result in cracking or 
fracture of the struts, and consequent reduced structural integrity 
and possible separation of the strut and engine from the airplane; 
accomplish the following:

Repetitive Inspections/Corrective Action

    (a) Within 6 months after the effective date of this AD: Do a 
detailed inspection of the pylon skin and internal structure of the 
nacelle struts adjacent to and aft of the precooler exhaust vent for 
heat discoloration, wrinkling, and cracking, per the Work 
Instructions of Boeing Special Attention Service Bulletin 747-54-
2210, dated December 19, 2001. Repeat the inspection at least every 
18 months.

    Note 2: For the purposes of this AD, a detailed 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 any sign of heat discoloration is found, but there is no 
wrinkling: Before further flight, do a conductivity test of the 
discolored area(s) per the service bulletin. If the conductivity 
test is within the limits specified in Figures 3 and 4, as 
applicable, of the Work Instructions of the service bulletin, and no 
cracking is found, before further flight, do a penetrant or high 
frequency eddy current (HFEC) inspection for cracking.
    (2) If any sign of wrinkling is found: Before further flight, do 
a penetrant or HFEC inspection of the wrinkled area(s) for cracking, 
per the service bulletin.
    (3) If any sign of cracking is found, before further flight, do 
the corrective action required by paragraph (b) of this AD.
    (b) If, during any inspection or test done by this AD, any 
wrinkling or cracking is found, or the conductivity limits exceed 
the limits specified in Figures 3 and 4, as applicable, of the Work 
Instructions of the service bulletin: Before further flight, repair 
per a method approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA; or per data meeting the type certification basis 
of the airplane approved by a Boeing Company Designated Engineering 
Representative who has been authorized by the Manager, Seattle ACO, 
to make such findings. For a repair method to be approved, the 
approval must specifically reference 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permit

    (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 November 19, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-30027 Filed 11-26-02; 8:45 am]
BILLING CODE 4910-13-P