[Federal Register Volume 60, Number 41 (Thursday, March 2, 1995)]
[Rules and Regulations]
[Pages 11621-11623]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-4853]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 92-ANE-34; Amendment 39-9163; AD 95-04-11]


Airworthiness Directives; Textron Lycoming ALF502R and ALF502L 
Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to Textron Lycoming ALF502R series turbofan engines, 
that currently requires the establishment of a reduced stress rupture 
retirement life limit for certain third stage turbine disks. This 
amendment establishes a new increased stress rupture retirement life 
limit for certain third stage turbine disks used in conjunction with 
third stage turbine nozzles that have improved cooling effectiveness, 
expands the applicability by adding the ALF502L series engines, and 
establishes other new reduced stress rupture retirement life limits. 
This amendment is prompted by the introduction of an improved design 
third stage turbine nozzle, and a new reduced stress rupture retirement 
life limit for certain third stage turbine disks on the ALF502L series 
engines. The actions specified by this AD are intended to prevent a 
total loss of engine power, inflight engine shutdown, and possible 
damage to the aircraft.

DATES: Effective April 3, 1995.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of April 3, 1995.

ADDRESSES: The service information referenced in this AD may be 
obtained from AlliedSignal Engines, 550 Main Street, Stratford, CT 
06497; (203) 385-1470. 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 
01803-5299; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Eugene Triozzi, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (617) 
238-7148, fax (617) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 90-25-02, 
Amendment 39-6811 (55 FR 48592, November 21, 1990), which is applicable 
to Textron Lycoming ALF502R series turbofan engines, was published in 
the Federal Register on March 15, 1993 (58 FR 13711). That action 
proposed to expand the applicability by adding the ALF502L series. That 
action would also provide for increased stress rupture retirement life 
limits for certain third stage turbine disks when used in conjunction 
with third stage turbine nozzles that have improved cooling 
effectiveness.
    On October 28, 1994, AlliedSignal Inc. purchased the turbine engine 
product line of Textron Lycoming, but as of this date the anticipated 
name change on the type certificate for the [[Page 11622]] ALF502L 
series engines has not occurred.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the one comment received.
    The commenter concurs with the rule as proposed.
    Since publication of the NPRM, Textron Lycoming has issued Revision 
22 to Service Bulletin ALF502 72-0002, dated December 23, 1992, that 
introduces new part numbered rotor parts and adds pro-rating formulas 
to include the new parts. The technical content in regard to affected 
components is unchanged. This final rule has been revised to reference 
this later revision.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    There are approximately 900 Textron Lycoming ALF502R and ALF502L 
series turbofan series engines of the affected design in the worldwide 
fleet. The FAA estimates that 300 engines installed on aircraft of U.S. 
registry will be affected by this AD, and that 100 are ALF502L series 
engines that are subject to the reduction in service life requirement. 
It is also estimated that to implement the reduction in service life 
requirement it will take approximately 14 work hours per engine to 
accomplish the required actions, and that the average labor rate is $55 
per work hour. The reduction in service life requirement will cost 
approximately $30,000 per engine. Based on these figures, the total 
cost impact of the AD on U.S. operators is estimated to be $3,077,000.
    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 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 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-6811 (55 FR 
48592, November 21, 1990) and by adding a new airworthiness directive, 
Amendment 39-9163, to read as follows:

95-04-11  Textron Lycoming: Amendment 39-9163. Docket 92-ANE-34. 
Supersedes AD 90-25-02, Amendment 39-6811.

    Applicability: Textron Lycoming ALF502R and ALF502L series 
turbofan engines installed on but not limited to British Aerospace 
BAe-146 and Canadair Challenger CL600 aircraft.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent a total loss of engine power, inflight shutdown, and 
possible damage to the aircraft, accomplish the following:
    (a) Remove from service and replace with a serviceable part 
third stage turbine disks, Part Numbers (P/N) 2-143-030-05, 2-143-
030-08, and 2-143-030-14, as follows:
    (1) For disks that have been installed only with third stage 
turbine nozzles P/Ns 2-141-130-52 or 2-141-120-53, remove from 
service as follows:
    (i) For disks that have accumulated 13,220 or more hours time in 
service (TIS) since new on the effective date of this AD, within the 
next 80 hours TIS after the effective date of this AD for the 
ALF502L engines, or within the next 80 hours TIS after December 11, 
1990, (the effective date of AD 90-25-02), for the ALF502R engines, 
but not to exceed the existing cyclic life limit,
    (ii) For disks that have accumulated less than 13,220 hours TIS 
since new on the effective date of this AD, prior to accumulating 
more than 13,300 hours TIS since new, but not to exceed the existing 
cyclic life limit.
    (iii) Thereafter, remove disks prior to accumulating more than 
13,300 hours TIS since new, but not to exceed the existing cyclic 
life limit.
    (2) For disks that have been installed only with third stage 
turbine nozzles, P/Ns 2-141-120-57 or 2-141-120-R56, remove from 
service as follows:
    (i) For disks that have accumulated 27,420 or more hours TIS 
since new on the effective date of this AD, within the next 80 hours 
TIS after the effective date of this AD, but not to exceed the 
existing cyclic life limit.
    (ii) For disks that have accumulated less than 27,420 hours TIS 
since new on the effective date of this AD, prior to accumulating 
more than 27,500 hours TIS since new, but not to exceed the existing 
cyclic life limit.
    (iii) Thereafter, remove disks prior to accumulating more than 
27,500 hours TIS since new, but not to exceed the existing cyclic 
life limit.
    (3) For disks that have been installed with both third stage 
turbine nozzles, P/Ns 2-141-120-52 or 2-141-120-53, and third stage 
turbine nozzles, P/Ns 2-141-120-57 or 2-141-120-R56, remove from 
service as follows:
    (i) Determine the prorated hourly life limit in accordance with 
the procedure defined in the Accomplishment Instructions, Section 
2.B.(2) of Textron Lycoming Service Bulletin (SB) ALF502 72-0002 
(for ALF502R series engines) Revision 22, dated December 23, 1992, 
or Textron Lycoming SB ALF502 72-0004 (for ALF502L series engines) 
Revision 11, dated June 17, 1987. From this prorated hourly life 
limit, subtract 80 hours TIS to determine the compliance threshold 
for each engine model.
    (ii) For disks that have equalled or exceeded the compliance 
threshold on the effective date of this AD, within the next 80 hours 
TIS, but not to exceed the existing cyclic life limit.
    (iii) For disks that have accumulated less than the compliance 
threshold on the effective date of this AD, prior to accumulating 
more than the calculated prorated hourly life limit.
    (iv) Thereafter, remove disks at or prior to accumulating the 
prorated hourly life limit, but not to exceed the existing cyclic 
life limit.
    (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. The 
request should be forwarded through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Engine Certification Office.

    Note: Information concerning the existence of approved 
alternative method of compliance with this AD, if any, may be 
obtained from the Engine Certification Office.

    (c) The actions required by this AD shall be done in accordance 
with the following Textron Lycoming SB's:

                                                                        
[[Page 11623]]                                                          
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     Document No.         Pages      Revision             Date          
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ALF502 72-0002.......      1-2              22  Dec. 23, 1992.          
                             3              18  Dec. 21, 1989.          
                           4-7              22  Dec. 23, 1992.          
                             8              21  Sept. 25, 1992.         
                          9-10              22  Dec. 23, 1992.          
                            11              21  Sept. 25, 1992.         
                         12-26              22  Dec. 23, 1992.          
                            27              21  Sept. 25, 1992.         
    Total pages: 27.                                                    
ALF502 72-0004.......     1-16              11  June 17, 1987.          
    Total pages: 16.                                                    
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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 Textron Lycoming, 550 Main Street, 
Stratford, CT 06497; (203) 385-1470. 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.
    (d) This amendment becomes effective on April 3, 1995.

    Issued in Burlington, Massachusetts, on February 16, 1995.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 95-4853 Filed 3-1-95; 8:45 am]
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