[Federal Register Volume 64, Number 23 (Thursday, February 4, 1999)]
[Rules and Regulations]
[Pages 5592-5594]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-2494]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-83-AD; Amendment 39-11023; AD 99-03-09]
RIN 2120-AA64


Airworthiness Directives; Allison Engine Company, Inc. AE 2100A, 
AE 2100C, and AE 2100D3 Series Turboprop Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to Allison Engine Company, Inc. AE 2100A, AE 2100C, and 
AE 2100D3 series turboprop engines. This action requires removing from 
service affected turbine wheels prior to exceeding new, reduced cyclic 
life limits. This amendment is prompted by the results of a refined 
life analysis. The actions specified in this AD are intended to prevent 
an uncontained turbine wheel failure, which could result in damage to 
the aircraft.

DATES: Effective February 19, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 19, 1999.
    Comments for inclusion in the Rules Docket must be received on or 
before April 5, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 98-ANE-83-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: ``9-ad-
[email protected].'' Comments sent via the Internet must contain the 
docket number in the subject line.
    The service information referenced in this AD may be obtained from 
Allison Engine Company, Inc., P.O. Box 420, Speed Code U-15, 
Indianapolis, IN 46206-0420, telephone (317) 230-6674. This information 
may be examined 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.

FOR FURTHER INFORMATION CONTACT: John Tallarovic, Aerospace Engineer, 
Chicago Aircraft Certification Office, FAA, Small Airplane Directorate, 
Office Address; telephone (847) 294-8180, fax (847) 294-7834.

SUPPLEMENTARY INFORMATION: Allison Engine Company, Inc., the 
manufacturer of AE 2100A, AE 2100C, and AE 2100D3 series turboprop 
engines, suspects that certain serial number turbine wheels may have 
Tungsten contamination. Additionally, the manufacturer reevaluated the 
effect on the service life of a wheel surface treatment, which is part 
of the current manufacturing process. A refined life analysis, which 
took both the possibility of Tungsten contamination and the surface 
treatment into account, revealed new maximum service lives 
significantly lower than those previously published. This condition, if 
not corrected, could result in an uncontained turbine wheel failure, 
which could result in damage to the aircraft.
    The FAA has reviewed and approved the technical contents of Rolls-
Royce Alert Service Bulletin (ASB) AE 2100A-A-72-191, AE 2100C-A-72-
141, and AE 2100D3-A-72-130, all dated December 17, 1998, that list 
new, reduced cyclic life limits for affected turbine wheels.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other engines of the same type design, this AD is 
being issued to prevent uncontained turbine wheel failure. This AD 
requires removing from service affected turbine wheels prior to 
exceeding new, reduced cyclic life limits. The actions shall be 
accomplished in accordance with the ASB's described previously.
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD 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 98-ANE-83-AD.'' The postcard will be date stamped and 
returned to the commenter.
    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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and is not a ``significant regulatory action'' 
under Executive Order 12866. It has been determined further that this

[[Page 5593]]

action involves an emergency regulation under DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979). If it is determined 
that this emergency regulation otherwise would be significant under DOT 
Regulatory Policies and Procedures, a final regulatory evaluation will 
be prepared and placed in the Rules Docket. A copy of it, if filed, 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:

99-03-09  Allison Engine Company, Inc.: Amendment 39-11023. Docket 
98-ANE-83-AD.

    Applicability: Allison Engine Company, Inc. AE 2100A, AE 2100C, 
and AE 2100D3 series turboprop engines, with turbine wheels, part 
numbers (P/Ns) 23053358, 23059878, 23062373, 23062376, 23063462, 
23064473, 23064474, 23064822, 23065891, 23065892, 23066791, and 
23068072 installed. These engines are installed on but not limited 
to Saab Aircraft AB 2000, Industri Pesawat Terbang Nusantara (IPTN) 
Model N-250-100, and Lockheed Martin Model 382J (Military C130J) 
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 (e) 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 an uncontained turbine wheel failure, which could 
result in damage to the aircraft, accomplish the following:
    (a) Remove from service the following turbine wheels installed 
in AE 2100A series engines prior to exceeding new, reduced cyclic 
life limits and replace with serviceable parts as follows:
    (1) 4th Stage Turbine Wheels, P/N 23053358, prior to 8,900 
cycles since new (CSN).
    (2) 1st Stage Turbine Wheels, P/N 23062373, identified by serial 
numbers (S/N's) in Table 9 of Rolls-Royce Alert Service Bulletin 
(ASB) No. AE 2100A-A-72-191, dated December 17, 1998, prior to 
10,000 CSN.
    (3) 1st Stage Turbine Wheels, P/N 23062376, prior to 11,600 CSN.
    (4) 2nd Stage Turbine Wheels, P/N 23063462, identified by S/N's 
in Table 10 of Rolls-Royce ASB No. AE 2100A-A-72-191, dated December 
17, 1998, prior to 10,000 CSN.
    (5) 2nd Stage Turbine Wheels, P/N 23063462, not identified by S/
N's in Rolls-Royce ASB No. AE 2100A-A-72-191, dated December 17, 
1998, prior to 12,400 CSN.
    (6) 2nd Stage Turbine Wheels, P/N 23064822, prior to 12,400 CSN.
    (7) 1st Stage Turbine Wheels, P/N 23065891, identified by S/N's 
in Table 9 of Rolls-Royce ASB No. AE 2100A-A-72-191, dated December 
17, 1998, prior to 10,000 CSN.
    (8) 2nd Stage Turbine Wheels, P/N 23065892, identified by S/N's 
in Table 10 of Rolls-Royce ASB No. AE 2100A-A-72-191, dated December 
17, 1998, prior to 10,000 CSN.
    (9) 2nd Stage Turbine Wheels, P/N 23065892, not identified by S/
N's in Rolls-Royce ASB No. AE 2100A-A-72-191, dated December 
17,1998, prior to 12, 400 CSN.
    (10) 1st Stage Turbine Wheels, P/N 23066791, prior to 11,600 
CSN.

    Note 2: Rolls-Royce ASB No. AE 2100A-A-72-191, dated December 
17, 1998, provides information concerning specific S/N wheels and 
their cyclic life limits.

    (b) Remove from service the following turbine wheels installed 
in AE 2100C series engines prior to exceeding new, reduced cyclic 
life limits and replace with serviceable parts as follows:
    (1) 4th Stage Turbine Wheels, P/N 23053358, prior to 8,900 CSN.
    (2) 1st Stage Turbine Wheels, P/N 23062373, identified by S/N's 
in Table 9 of Rolls-Royce ASB No. AE 2100C-A-72-141, dated December 
17, 1998, prior to 10,000 CSN.
    (3) 2nd Stage Turbine Wheels, P/N 23063462, identified by S/N's 
in Table 10 of Rolls-Royce ASB No. AE 2100C-A-72-141, dated December 
17, 1998, prior to 10,000 CSN.
    (4) 2nd Stage Turbine Wheels, P/N 23063462, not identified by S/
N's in Rolls-Royce ASB No. AE 2100C-A-72-141, dated December 17, 
1998, prior to 12,400 CSN.
    (5) 1st Stage Turbine Wheels, P/N 23065891, identified by S/N's 
in Table 9 of Rolls-Royce ASB No. AE 2100C-A-72-141, dated December 
17, 1998, prior to 10,000 CSN.
    (6) 2nd Stage Turbine Wheels, P/N 23065892, identified by S/N's 
in Table 10 of Rolls-Royce ASB No. AE 2100C-A-72-141, dated December 
17, 1998, prior to 10,000 CSN.
    (7) 2nd Stage Turbine Wheels, P/N 23065892, not identified by S/
N's in Rolls-Royce ASB No. AE 2100C-A-72-141, dated December 17, 
1998, prior to 12,400 CSN.

    Note 3: Rolls-Royce ASB No. AE 2100C-A-72-141, dated December 
17, 1998, provides information concerning specific S/N wheels and 
their cyclic life limits.

    (c) Remove from service the following turbine wheels installed 
in AE 2100D3 series engines prior to exceeding new, reduced cyclic 
life limits and replace with serviceable parts as follows:
    (1) 4th Stage Turbine Wheels, P/N 23053358, identified by S/N's 
in Table 12 of Rolls-Royce ASB No. AE 2100D3-A-72-130, dated 
December 17, 1998, prior to 2,160 CSN.
    (2) 3rd Stage Turbine Wheels, P/N 23059878, identified by S/N's 
in Table 11 of Rolls-Royce ASB No. AE 2100D3-A-72-130, dated 
December 17, 1998, prior to 2,160 CSN.
    (3) 1st Stage Turbine Wheels, P/N 23062373, identified by S/N's 
in Table 9 of Rolls-Royce ASB No. AE 2100D3-A-72-130, dated December 
17, 1998, prior to 2,160 CSN.
    (4) 1st Stage Turbine Wheels, P/N 23062376, prior to 8,400 CSN.
    (5) 2nd Stage Turbine Wheels, P/N 23063462, identified by S/N's 
in Table 10 of Rolls-Royce ASB No. AE 2100D3-A-72-130, dated 
December 17, 1998, prior to 2,160 CSN.
    (6) 2nd Stage Turbine Wheels, P/N 23063462, not identified by S/
N's in Rolls-Royce ASB No. AE 2100D3-A-72-130, dated December 17, 
1998, prior to 7,500 CSN.
    (7) 2nd Stage Turbine Wheels, P/N 23064473, identified by S/N's 
in Table 10 of Rolls-Royce ASB No. AE 2100D3-A-72-130, dated 
December 17, 1998, prior to 2,160 CSN.
    (8) 2nd Stage Turbine Wheels, P/N 23064473, not identified by S/
N's in Rolls-Royce ASB No. AE 2100D3-A-72-130, dated December 17, 
1998, prior to 6,700 CSN.
    (9) 2nd Stage Turbine Wheels, P/N 23064474, prior to 7,500 CSN.
    (10) 1st Stage Turbine Wheels, P/N 23065891, identified by S/N's 
in Table 9 of Rolls-Royce ASB No. AE 2100D3-A-72-130, dated December 
17, 1998, prior to 2,160 CSN.
    (11) 2nd Stage Turbine Wheels, P/N 23065892, identified by S/N's 
in Table 10 of Rolls-Royce ASB No. AE 2100D3-A-72-130, dated 
December 17, 1998, prior to 2,160 CSN.

    (12) 2nd Stage Turbine Wheels, P/N 23065892, not identified by 
S/N's in Rolls-Royce ASB No. AE 2100D3-A-72-130, dated December 17, 
1998, prior to 7,500 CSN.
    (13) 2nd Stage Turbine Wheels, P/N 23068072, prior to 7,500 CSN.
    Note 4: Rolls-Royce ASB No. AE 2100D3-A-72-130, dated December 
17, 1998, provides information concerning specific serial number 
wheels and their cyclic life limits.

    (d) This AD establishes new cyclic life limits for the turbine 
wheels identified in paragraphs (a), (b), and (c) of this AD. Except 
in accordance with paragraph (e) of this AD, no alternative life 
limits may be approved for the turbine wheels identified in 
paragraphs (a), (b), and (c) of this AD.

[[Page 5594]]

    (e) 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, Chicago Aircraft Certification 
Office. Operators shall submit their requests through an appropriate 
FAA Principal Maintenance Inspector, who may add comments and then 
send it to the Manager, Chicago Aircraft Certification Office.

    Note 5: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Chicago Aircraft Certification 
Office.

    (f) The actions required by this AD shall be done in accordance 
with the following Rolls-Royce ASB's:

------------------------------------------------------------------------
             Document No.                Pages            Date
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AE 2100A-A-72-191.....................     1-8  Dec. 17, 1998.
AE 2100C-A-72-141.....................     1-8  Dec. 17, 1998.
AE 2100D3-A-72-130....................     1-8  Dec. 17, 1998.
 
    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 Allison Engine Company, Inc., P.O. 
Box 420, Speed Code U-15, Indianapolis, IN 46206-0420, telephone 
(317) 230-6674. 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.
    (g) This amendment becomes effective on February 19, 1999.

    Issued in Burlington, Massachusetts, on January 28, 1999.
Mark C. Fulmer,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 99-2494 Filed 2-3-99; 8:45 am]
BILLING CODE 4910-13-P