AD 2000-08-01

[Federal Register Volume 65, Number 75 (Tuesday, April 18, 2000)]
[Rules and Regulations]
[Pages 20714-20715]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 00-9358]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-61-AD; Amendment 39-11687; AD 2000-08-01]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce plc Tay 650-15 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to Rolls-Royce plc Tay 650-15 series turbofan engines. 
This AD requires the establishment of cyclic life limits for stage 1 
high pressure turbine (HPT) and stage 1 low pressure turbine (LPT) 
disks operating under new flight plan profiles. This amendment is 
prompted by reports that, on some engines, cracks in the stage 1 HPT 
and stage 1 LPT disks could initiate and propagate at a faster rate 
than forecast under the flight plan profiles originally published at 
the time the engine design was certified. The actions specified by this 
AD are intended to prevent crack initiation and propagation leading to 
turbine disk failure, which could result in an uncontained engine 
failure and damage to the aircraft.

DATES: Effective date June 19, 2000.
    The incorporation by reference of certain publications listed in 
the rule is approved by the Director of the Federal Register as of June 
19, 2000.

ADDRESSES: The service information referenced in this AD may be 
obtained from Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, UK, 
telephone 011-44-1332-242424. This information may be examined at the 
Federal Aviation Administration (FAA), New England Region, Office of 
the Regional 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: James Lawrence, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone 781-
238-7176, fax 781-238-7199.

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 Rolls-Royce plc (R-R) Tay 650-15 
series turbofan engines

[[Page 20715]]

was published in the Federal Register on January 12, 2000 (65 FR 1831). 
That action proposed to establish life limits for stage 1 HPT and stage 
1 LPT disks operated under the new flight plan profiles, C and D; 
require the removal from service of stage 1 HPT and stage 1 LPT disks 
prior to reaching new, lower cyclic life limits; and replace those 
disks with serviceable parts in accordance with R-R Service Bulletin 
TAY-72-1479, dated July 20, 1999.
    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.

Economic Analysis

    There are approximately 242 engines of the affected design in the 
worldwide fleet. The FAA estimates that three engines installed on 
aircraft of U.S. registry will be affected by this AD, and that the 
prorated life reduction would cost $26,658 per engine. Based on these 
figures, the total cost impact of the proposed AD on US operators is 
estimated to be $79,974.

Regulatory Impact

    This rule does not have federalism implications, as defined in 
Executive Order (EO) No. 13132, because it does 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. Accordingly, 
the FAA has not consulted with state authorities prior to publication 
of this rule.
    For the reasons discussed above, I certify that this action (1) Is 
not a ``significant regulatory action'' under EO No. 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 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 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

2000-08-01  Rolls-Royce plc: Amendment 39-11687. Docket 99-NE-61-AD.

    Applicability: Rolls-Royce plc (R-R) Tay 650-15 series turbofan 
engines, with stage 1 high pressure turbine (HPT) disks, part 
numbers (P/Ns) JR32013 and JR33838, and stage 1 low pressure turbine 
(LPT) disks, P/N JR32318A. These engines are installed on but not 
limited to Fokker F.28 Mark 0100 (F100) 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 (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 prevent crack initiation and propagation leading to turbine 
disk failure, which could result in an uncontained engine failure 
and damage to the aircraft, accomplish the following:

Flight Plan Profile C

    (a) Remove from service stage 1 HPT disks, P/Ns JR32013 and 
JR33838, and stage 1 LPT disks, P/N JR32318A, operated under flight 
plan profile C, as defined in the R-R Tay Engine Manual, 70-01-10, 
pages 1-10, prior to accumulating 18,000 cycles-since-new (CSN), and 
replace with serviceable parts.

Flight Plan Profile D

    (b) Remove from service stage 1 HPT disks, P/Ns JR32013 and 
JR33838, and stage 1 LPT disks, P/N JR32318A, operated under flight 
plan profile D, as defined in the R-R Tay Engine Manual, 70-01-10, 
pages 1-10, prior to accumulating 14,250 CSN, and replace with 
serviceable parts.

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, 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.

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 aircraft to a location where 
the requirements of this AD can be accomplished.

Incorporation by Reference Material

    (e) The actions of this AD shall be done in accordance with R-R 
Service Bulletin TAY-72-1479, dated July 20, 1999. 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 Rolls-Royce plc, P.O. Box 31, Derby, 
DE24 8BJ, UK, telephone 011-44-1332-242424 . Copies may be inspected 
at the FAA, New England Region, Office of the Regional 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.

Effective Date of This AD

    (f) This amendment becomes effective on June 19, 2000.

    Issued in Burlington, Massachusetts, on April 7, 2000.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 00-9358 Filed 4-17-00; 8:45 am]
BILLING CODE 4910-13-U