AD 83-03-02 R1

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AD Number:
83-03-02 R1
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
ALLISON GAS TURBINE OPERATIONS/DETROIT DIESEL ALLISON (ALLISON) Model 250-C20, -C20B, -C20C (T63- A7...Show more
Subject:
Slotted Third Stage Turbine Wheels
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
02/28/1984
Make:
Rolls-Royce Corporation
Model:
250-B17 | 250-B17B | 250-B17C | 250-B17D | 250-C20 | 250-C20B | 250-C20C (T63-A-720) | 250-C20F
Product Type:
Engine
Product Subtype:
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 83-03-02 R1
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4814

AD NUMBER:   83-03-02 R1

SUBJECT HEADING:   ALLISON GAS TURBINE OPERATIONS/DETROIT DIESEL ALLISON (ALLISON) Model 250-C20, -C20B, -C20C (T63- A720), -C20F, -B17, -B17B, -B17C, and -B17D Engines

ACTION:  

SUMMARY:  

DATES:   Effective February 28, 1984.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   83-03-02 R1 ALLISON GAS TURBINE OPERATIONS/DETROIT DIESEL ALLISON (ALLISON): Amendment 39-4560 as amended by Amendment 39-4814. Applies to all Model 250-C20, -C20B, -C20C (T63- A720), -C20F, -B17, -B17B, -B17C, and -B17D engines equipped with the following slotted third stage turbine wheels:


PART NO.	TYPE OF SHROUD	PART NO.	TYPE OF SHROUD
6887113	Full slot	6898823	Crimped full slot
6888633	Full slot	6899364	Crimped full slot
6896863	Crimped full slot	6899406	Crimped center slot
6898551	Center slot	6899415	Crimped center slot
6898567	Center slot	6899416	Crimped center slot
6898733	Center slot	6899417	Crimped center slot
6898743	Center slot	6899418	Crimped center slot
6898753	Center slot	6899419	Crimped center slot
6898763	Center slot		

Accomplish the following to prevent possible engine power loss resulting from partial blade and/or shroud separation of slotted third stage turbine wheels:
1. Compliance required, as indicated, unless already accomplished:
Remove from service and replace affected turbine wheels per the accomplishment instructions provided in Allison Commercial Engine Alert Bulletin CEB-A-1174/1146, Revision 3 dated January 26, 1984, or FAA approved equivalent, in accordance with the following schedule:


Wheel Time Since New (TSN) - Hours	Remove
1650 or more	Within the next 100 hours time in service.
1000 or more and less than 1650	Within the next 400 hours time in service, or prior to exceeding 1750 hours TSN, whichever comes first.
More than 500 and less than 1000	Within the next 600 hours time in service, or prior to exceeding 1500 hours TSN, whichever comes first.
500 or less	Within the next 850 hours time in service, or prior to exceeding 1100 hours TSN, whichever comes first.

2. Compliance required not later than August 12, 1983, unless already accomplished:
a. Placards, markings, or flight manual changes shall be provided to flight crews to avoid sustained operation of all affected engines between 90 and 98 percent N2, except during transients, while maintaining safe flight practices. This restriction also applies to autorotation practice and engine idle during engine-out simulation on multiengine aircraft.
b. During all ground operation of affected turbine wheels installed in 250-C20, -C20B, C20C (T63-A720 engines, the engine N1 speed must be maintained at ground idle, except during transient operations, when performing required operational checks, or in high or gusty wind conditions, or where safety would be adversely affected. Placards, markings, or flight manual changes shall be used to advise flight crews of the ground operating restriction.
c. During all ground operation of affected turbine wheels installed in 250-B17, -B17B, -B17C engines, the engine N2 speed must be maintained below 90 percent N2 r.p.m., except during transient operation, when performing required operational checks or in high or gusty wind conditions, or where safety would be adversely affected. Placards, markings, or flight manual changes shall be used to advise flight crews of the ground operating restriction.
Upon request of the operator, an equivalent means of compliance with the requirements of this AD may be approved by the Manager, Chicago Aircraft Certification Office, FAA, Central Region.
Special flight permits may be issued in accordance with FAR's 21.197 and 21.199 to operate aircraft to a base where compliance with this AD can be accomplished.
The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Allison Gas Turbine Operations, General Motors Corporation, Indianapolis, Indiana 46206-0420. These documents may also be examined at the New England Regional Office, 12 New England Executive Park, Burlington, Massachusetts 01803. A historical file on this AD is maintained by the FAA at the New England Regional Office.
This AD supersedes Amendment 39-3011, 42 FR 43969, AD 77-18-03.
Amendment 39-4560 became effective June 13, 1983.
This Amendment 39-4814 becomes effective February 28, 1984.

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