[Federal Register Volume 62, Number 5 (Wednesday, January 8, 1997)]
[Rules and Regulations]
[Pages 1039-1041]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-474]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-ANE-06; Amendment 39-9864; AD 96-26-01]
RIN 2120-AA64


Airworthiness Directives; General Electric Aircraft Engines CT7 
Series Turboprop Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to General Electric Aircraft Engines (GE) CT7 series 
turboprop engines, that requires replacement of the gas generator 
turbine stage 2 forward cooling plates prior to the published cyclic 
life limits. The AD also defines the new, reduced cyclic life limits 
for the affected forward cooling plates. This amendment is prompted by 
reports of gas generator turbine stage 2 forward

[[Page 1040]]

cooling plate failures. The actions specified by this AD are intended 
to prevent gas generator turbine stage 2 forward cooling plate failure, 
which could result in an uncontained engine failure.

DATES: Effective March 10, 1997.

    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 10, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from GE Aircraft Engines, 1000 Western Ave., Lynn, MA 01910; 
telephone (617) 594-3140, fax (617) 594-4805. 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: Dave Keenan, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (617) 
238-7139, fax (617) 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 General Electric Aircraft Engines 
(GE) CT7 series turboprop engines was published in the Federal Register 
on September 17, 1996 (61 FR 48866). That action proposed to require 
replacement of the gas generator turbine stage 2 forward cooling plate 
within 30 days after the effective date of the AD, or prior to reaching 
the new, reduced cyclic life limits listed in the Accomplishment 
Instructions of GE Aircraft Engines (CT7-TP Series) SB A72-381, dated 
January 17, 1996, whichever occurs later.
    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 an additional paragraph (e) is 
necessary to fully implement the new life limits for gas generator 
turbine (GGT) stage 2 forward cooling plates, Part Number (P/N) 
60604T10P01 and P/N 5086T91P02. The FAA has determined that air safety 
and the public interest require the adoption of the rule with this 
change, and that this change will neither increase the economic burden 
on any operator nor increase the scope of the AD.
    There are approximately 1,100 engines of the affected design in the 
worldwide fleet. The FAA estimates that 500 engines installed on 
aircraft of U.S. registry will be affected by this AD, that it will 
take approximately 8 work hours per engine to accomplish the required 
actions, and that the average labor rate is $60 per work hour. Parts 
will be supplied by the manufacturer to operators under GE's Engine 
Care Maintenance Plan (ECMP). At this time, all operators fall under 
the ECMP. Based on these figures, the total cost impact of the AD of 
U.S. operators is estimated to be $240,000.
    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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

96-26-01  General Electric Aircraft Engines: Amendment 39-9864. 
Docket 96-ANE-06.

    Applicability: General Electric Aircraft Engines (GE) Models 
CT7-5A2, -7A, -9B, and -9C turboprop engines, with gas generator 
turbine (GGT) stage 2 forward cooling plates, Part Number (P/N) 
6064T10P01 and P/N 5086T91P02, installed. These engines are 
installed on but not limited to Construcciones Aeronauticas, SA 
(CASA) CN-235 series and SAAB-SCANIA SF340 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 of 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 GGT stage 2 forward cooling plate failure, which 
could result in an uncontained engine failure, accomplish the 
following:
    (a) Within 30 days after the effective date of this AD, or prior 
to reaching the new, reduced cyclic life limits listed in the 
Accomplishment Instructions of GE Aircraft Engines (CT7-TP Series) 
Service Bulletin (SB) A72-381, dated January 17, 1996, whichever 
occurs later, remove from service GGT stage 2 forward cooling 
plates, and replace with a serviceable part, which is defined as a 
GGT stage 2 forward cooling plate that has less than the new, 
reduced cyclic limits on the effective date of this AD, as defined 
in that SB.
    (b) This action establishes the following new, reduced cyclic 
life limits for affected GGT stage 2 forward cooling plates:
    (1) 8,000 cycles since new (CSN) for GGT stage 2 forward cooling 
plates, P/N 6064T10P01, identified by serial numbers listed in 
Tables 1 and 2 of GE Aircraft Engines (CT7-TP Series) SB No. A72-
381, dated January 17, 1996, for GE CT7-5A2, -7A, -9B, and -9C 
engine models.
    (2) 12,000 CSN for GGT stage 2 forward cooling plates, P/N 
6064T10P01 (not listed in (1) above), and P/N 5086T91P02, for GE 
CT7-5A2 and -7A engine models.
    (3) 9,000 CSN for GGT stage 2 forward cooling plates, P/N 
6064T10P01 (not listed in (1) above), and P/N 5086T91P02, for GE 
CT7-9B/-9C engine models.
    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be

[[Page 1041]]

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 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Engine Certification Office.
    (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.
    (e) Thereafter, except as provided in paragraphs (c) and (d) of 
this AD, no alternative replacement times may be approved for GGT 
stage 2 forward cooling plates, P/N 6064T10P01, and P/N 5086T91P02.
    (f) The actions required by this AD shall be done in accordance 
with the following GE Aircraft Engines (CT7-TP Series) SB:

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            Document No               Pages              Date           
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A72-381............................     1-13  Jan. 17, 1996.            
Total Pages: 13.                                                        
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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 GE Aircraft Engines, 1000 
Western Ave., Lynn, MA 01910; telephone (617) 594-3140, fax (617) 
594-4805. 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 March 10, 1997.

    Issued in Burlington, Massachusetts, on December 16, 1996.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 97-474 Filed 1-7-97; 8:45am]
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