[Federal Register Volume 61, Number 177 (Wednesday, September 11, 1996)]
[Rules and Regulations]
[Pages 47806-47808]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-22772]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-ANE-55; Amendment 39-9737; AD 96-18-13]
RIN 2120-AA64
Airworthiness Directives; AlliedSignal Inc. TFE731 Series
Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to AlliedSignal Inc. (formerly Garrett Engine Division)
TFE731 series turbofan engines, that requires removing certain fan
rotor disks from service in accordance with a drawdown schedule, and
would establish new fan rotor disk life limits. This amendment is
prompted after additional analyses revealed that stress levels in the
fan rotor disk dovetail slots for the applicable engine models are
higher than initially calculated. The actions specified by this AD are
intended to prevent uncontained failure of the fan rotor disk due to
fatigue cracking in the dovetail slots, which can result in inflight
engine shutdowns, severe secondary damage, and fan rotor assembly
separation from the engine.
DATES: Effective November 12, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of November 12, 1996.
ADDRESSES: The service information referenced in this AD may be
obtained from AlliedSignal Aerospace, Attn: Data Distribution, M/S 64-
3/2101-201, P.O. Box 29003, Phoenix, AZ 85038-9003; telephone (602)
365-2493, fax (602) 365-5577. This information may be examined at the
Federal Aviation Administration (FAA), New England Region, Office of
the Assistant Chief Counsel, 12 New England Executive Park, Burlington,
MA; or at the Office of the Federal Register, 800 North Capitol Street,
NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Joseph Costa, Aerospace Engineer, Los
Angeles Aircraft Certification Office, FAA, Transport Airplane
Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; telephone
(310) 627-5246; fax (310) 627-5210.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to AlliedSignal Inc. (formerly
Garrett Engine Division) TFE731 series turbofan engines was published
in the Federal Register on March 22, 1996 (61 FR 11790). That action
proposed to require removing certain fan rotor disks from service in
accordance with a drawdown schedule and would establish new fan rotor
disk life limits in accordance with AlliedSignal Engines Alert Service
Bulletin (ASB) No. TFE731-A72-3569, dated May 31, 1995, and ASB No.
TFE731-A72-3570, dated May 31, 1995.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. No comments were received on the
proposal or the FAA's determination of the cost to the public. The FAA
has determined that air safety and the public interest require the
adoption of the rule as proposed.
There are approximately 5,000 engines of the affected design in the
worldwide fleet. The FAA estimates that 2,500 engines installed on
aircraft of U.S. registry will be affected by this AD, that it will
take approximately 16 work hours per engine to accomplish the required
actions, and that the average labor rate is $60 per work hour. Based on
these figures, the total cost impact of the AD on U.S. operators is
estimated to be $2,400,000.
The regulations adopted herein will 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
[[Page 47807]]
levels of government. Therefore, in accordance with Executive Order
12612, it is determined that this final rule does not have sufficient
federalism implications to warrant the preparation of a Federalism
Assessment.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it 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 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
96-18-13 AlliedSignal Inc.: Amendment 39-9737. Docket 95-ANE-55.
Applicability: AlliedSignal Inc. (formerly Garrett Engine
Division) Models TFE731-2, -2A, -3, -3A, -3AR, -3B, -3BR, -3C, -3CR,
-3D, -3DR, -3R, and -4R turbofan engines, installed on, but not
limited to the following aircraft: Avions Marcel Dassault Falcon 10,
50, 100 series; Learjet 31, 35, 36, and 55 series; Lockheed-Georgia
1329-23 and -25 series; Israel Aircraft Industries 1124 series and
1125 Westwind series; Cessna Model 650, Citations III, VI, and VII;
Raytheon British Aerospace HS-125 series; and Sabreliner NA-265-65.
Note: 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 (d) 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 prevent uncontained failure of the fan rotor disk due to
fatigue cracking in the dovetail slots, which can result in inflight
engine shutdowns, severe secondary damage, and fan rotor assembly
separation from the engine, accomplish the following:
(a) For engines equipped with fan rotor disks, part numbers (P/
N's) 3072162-5, 3073436-5, 3073539-(All), and 3074529-(All), where
(All) denotes any dash number, remove fan rotor disks from service
and install a serviceable disk in accordance with the Accomplishment
Instructions of AlliedSignal Engines Alert Service Bulletin (ASB)
No. TFE731-A72-3569, dated May 31, 1995, as required by the
following schedule:
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Required fan rotor disk
Fan rotor disk cycles since new (CSN) retirement (remove from
on the effective date of this AD service)
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3,600 or less.......................... Not to exceed the new life
limit of 4,100 CSN.
3,601 to 5,500......................... Within the next 500 cycles
after the effective date of
this AD or prior to reaching
5,700 CSN, whichever occurs
first.
5,501 or greater....................... Within the next 200 cycles
after the effective date of
this AD, not to exceed 7,100
CSN.
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(b) For engines equipped with fan rotor disks, P/N 3072816-
(All), where (All) denotes any dash number, remove fan rotor disks
from service and install a serviceable disk in accordance with
Accomplishment Instructions of AlliedSignal Engines ASB No. TFE731-
A72-3570, dated May 31, 1995, as required by the following schedule:
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Required fan rotor disk
Fan rotor disk CSN on the effective retirement (remove from
date of this AD service)
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3,850 or less.......................... Not to exceed the new life
limit of 4,600 CSN.
3,851 to 6,000......................... Within the next 750 cycles
after the effective date of
this AD, or prior to reaching
6,500 CSN, whichever occurs
first.
6,001 or greater....................... Within the next 500 cycles
after the effective date of
this AD, not to exceed 10,000
CSN.
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(c) A serviceable part is one that has not exceeded the life
limits established by this AD.
(d) 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, Los Angeles Aircraft Certification
Office. The request should be forwarded through an appropriate FAA
Principal Maintenance Inspector, who may add comments and then send
it to the Manager, Los Angeles Aircraft Certification Office.
Note: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Los Angeles Aircraft Certification
Office.
(e) 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 aircraft to a location where
the requirements of this AD can be accomplished.
(f) The actions required by this AD shall be done in accordance
with the following AlliedSignal Engines ASBs:
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Document No. Pages Revision Date
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TFE731-A72-3569........................ 1-8 Original May 31, 1995.
Total Pages: 8. .............. ............................. ........................
TFE731-A72-3570........................ 1-8 Original May 31, 1995.
Total Pages: 8.
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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 AlliedSignal Aerospace, Attn: Data
Distribution, M/S 64-3/2101-201, P.O. Box
[[Page 47808]]
29003, Phoenix, AZ 85038-9003; telephone (602) 365-2493, fax (602)
365-5577. Copies may be inspected at the FAA, New England Region,
Office of the Assistant Chief Counsel, 12 New England Executive
Park, Burlington, MA; or at the Office of the Federal Register, 800
North Capitol Street NW., suite 700, Washington, DC.
(g) This amendment becomes effective on November 12, 1996.
Issued in Burlington, Massachusetts, on August 26, 1996.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 96-22772 Filed 9-10-96; 8:45 am]
BILLING CODE 4910-13-U
