[Federal Register Volume 64, Number 187 (Tuesday, September 28, 1999)]
[Proposed Rules]
[Pages 52259-52260]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-25122]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-39-AD]
RIN 2120-AA64


Airworthiness Directives; CFE Company Model CFE738-1-1B Turbofan 
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 CFE Company Model CFE738-1-1B 
turbofan engines. This proposal would require, on certain engines 
identified by serial numbers, a one-time visual inspection of Stage 2 
high pressure turbine (HPT) aft cooling plates, for nicks, dents, and 
scratches, and if present, dimensional inspection of indentation depth, 
repair if indentation is within acceptable limits, and, if necessary, 
replacement with serviceable parts. This AD would also require 
inspection of the Stage 2 HPT rotor disk post aft surface which mates 
with the Stage 2 HPT aft cooling plate, for raised metal and removal of 
the raised metal, if present. This proposal is prompted by reports of 
dented Stage 2 HPT aft cooling plates which occurred during the 
assembly of the cooling plate to the Stage 2 disk due to raised metal 
on the stage 2 HPT disk post aft mating surface. The actions specified 
by the proposed AD are intended to prevent aft HPT cooling plate 
failure, which could result in an uncontained engine failure and damage 
to the airplane.

DATES: Comments must be received by November 29, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 99-NE-39-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: ``9-ane-
[email protected]''. Comments sent via the Internet must contain the 
docket number in the subject line. Comments may be inspected at this 
location between 8:00 a.m. and 4:30 p.m., Monday through Friday, except 
Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from CFE Company, Data Distribution, MS 64-03/2101-201, P.O. 
Box 52170, Phoenix, AZ 85972-2170; telephone (602) 365-2493, fax (602) 
365-5577. This information may be examined at the FAA, New England 
Region, Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Keith Mead, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-
7744, fax (781) 238-7199.

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 should 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 notice may be changed in 
light of the comments received.
    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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NE-39-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, New England Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 99-NE-39-AD, 12 New England Executive Park, 
Burlington, MA 01803-5299.

Discussion

    The Federal Aviation Administration (FAA) has received reports of 
certain Stage 2 high pressure turbine (HPT) aft cooling plates, 
installed on CFE Company Model CFE738-1-1B turbofan engines, that were 
dented during the assembly of the cooling plate to the stage 2 disk due 
to raised metal on the aft mating face of the Stage 2 HPT rotor disk 
post. During the assembly of the high-pressure turbine rotor, the Stage 
2 disk is restrained with a special tool fixture. It has been 
determined that a condition occurring in this fixture as early as 
January 1998, may have resulted in raised metal on the disk post aft 
surface, which interfaces with the aft cooling plate. The higher the 
raised metal on the disk post, the deeper the dent in the cooling 
plate. The fixture has been repaired to prevent further occurrences and 
engines which may be effected by this condition have been identified by 
serial numbers. Analysis indicates that nicks, dents, and scratches on 
the Stage 2 HPT aft cooling plate exceeding a certain depth would 
result in a reduction in part cyclic life. This condition, if not 
corrected, could result in aft HPT cooling plate failure, which could 
result in an uncontained engine failure and damage to the airplane.

Service Information

    The FAA has reviewed and approved the technical contents of CFE 
Alert

[[Page 52260]]

Service Bulletin (ASB) CFE738-A72-8031, Revision 1, dated June 23, 
1999, that describes the dimensional inspection procedures for 
indentation depth on aft HPT cooling plates, inspection of the stage 2 
HPT rotor disk for raised metal, and the acceptance and repair criteria 
of the Stage 2 HPT aft cooling plate and HPT rotor disk.

Proposed Actions

    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, on engines identified by S/N, a one-time 
visual inspection of Stage 2 high pressure turbine (HPT) aft cooling 
plates for nicks, dents, and scratches, and if present, dimensional 
inspection of indentation depth, repair if indentation is within 
acceptable limits, and, if necessary, replacement with serviceable 
parts. This AD would also require inspection of the Stage 2 HPT rotor 
disk post aft surface which mates with the Stage 2 HPT aft cooling 
plate, for raised metal, and, removal of the raised metal, if present. 
The inspections would be required at the next shop visit after the 
effective date of this AD where the HPT assembly is sufficiently 
disassembled to afford access to the Stage 2 HPT aft cooling plate, but 
not later than 4,500 part cycles since new (CSN) in accordance with the 
ASB described previously.

Economic Analysis

    There are approximately 72 engines of the affected design in the 
worldwide fleet. The FAA estimates that 48 engines installed on 
aircraft of US registry would be affected by this proposed AD, that it 
would take approximately 4 work hours per engine to accomplish the 
proposed inspection if the inspection did not take place during 
scheduled maintenance, and that the average labor rate is $60 per work 
hour. Required parts would cost approximately $1,536 per engine. Based 
on these figures, the total cost impact of the proposed AD on US 
operators is estimated to be $106,560.
    The regulations proposed herein would not have substantial direct 
effects 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, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    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:

Company: Docket No. 99-NE-39-AD.
    Applicability: CFE Model CFE738-1-1B turbofan engines, serial 
numbers (S/Ns) 105267 through 105339, inclusive. These engines are 
installed on but not limited to Dassault-Breguet Falcon 2000 series 
aircraft.

    Note 1: This airworthiness directive (AD) applies to each engine 
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 engines 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 (b) 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.
    (a) At the next engine shop visit after the effective date of 
this AD where the HPT assembly is sufficiently disassembled to 
afford access to the Stage 2 HPT aft cooling plate, but not later 
than 4500 part cycles-since-new (CSN), accomplish the following in 
accordance with CFE Alert Service Bulletin (ASB) No. CFE738-A72-
8031, Revision 1, dated June 23, 1999 as follows:
    (1) Inspect the stage 2 HPT aft cooling plate for nicks, dents, 
and scratches on surface D in accordance with the requirements of 
ASB No. CFE738-A72-8031 paragraph 2.B.(1).
    (2) Repair those stage 2 HPT aft cooling plates with indentation 
less than 0.003 inch deep in accordance with ASB No. CFE738-A72-8031 
paragraph 2.B.(1).
    (3) Remove from service prior to further flight those stage 2 
HPT aft cooling plates which have nicks, dents, and/or scratches 
that exceed the acceptance limits in accordance with ASB No. CFE738-
A72-8031 paragraph 2.B.(1), and replace with a serviceable part.
    (4) Inspect the stage 2 HPT rotor disk post aft mating surface 
for raised metal, and remove raised metal if present in accordance 
with ASB No. CFE738-A72-8031 section 2.B.(2).
    (b) 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, Engine Certification Office (ECO). 
Operators shall submit their request through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, ECO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the ECO.

    (c) 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 inspection requirements of this AD can be accomplished.

    Issued in Burlington, Massachusetts, on September 20, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 99-25122 Filed 9-27-99; 8:45 am]
BILLING CODE 4910-13-U