# AD 81-03-02: 1st Stage Turbine Wheel

- Type: Airworthiness directive
- Status: Current
- Products: Rolls-Royce 501-D13, 501-D13A, 501-D13D, 501-D13E and 501-D13H
- Effective: January 28, 1981
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-4026
- Registered aircraft: 9 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/8C0CA26A61E8F23C8625685F006A134C.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/81-03-02

## The airworthiness directive

81-03-02 DETROIT DIESEL ALLISON: Amendment 39-4026. Applies to Model 501-D13, 501-D13A, 501- D13D, 501-D13E, 501-D13H engines equipped with 1st stage turbine wheel, Part Number 6851511; 2nd stage turbine wheel, Part Numbers 6847142 and 6876892; 3rd stage turbine wheel, Part Numbers 6845883 and 6849743; and 4th stage turbine wheel, Part Number 6876468.

Compliance is required as indicated. The following limits were established by manufacturer conducted tests, and analyses and are being imposed to preclude the possibility of catastrophic wheel failures which could occur subsequent to the intervals noted. The schedule for wheel removal is as follows and is a function of the wheel spline interference fit:

TURBINE WHEEL CYCLIC LIMITS (Spline Fit 0.0000-0.0009T) CYCLIC LIMITS (Spline Fit 0.001-0.0025T) Stage 1 24,000 cycles 30,000 cycles Stage 2 18,000 cycles 26,000 cycles Stage 3 16,000 cycles 22,000 cycles Stage 4 18,000 cycles 26,000 cyclesIt is the operator's responsibility to obtain wheel-to-shaft spline fit data from their overhauler to determine which fit applies to their respective turbine or turbines. Only wheels that have conformed to a .001T minimum fit throughout their entire utilization history qualify for the higher cyclic limits above.

NOTE: If any turbine wheel has more than the number of cycles appropriate for its retirement as shown in this table above on the effective date of this AD, it must be replaced prior to accruing 100 additional cycles.

The above cyclic limits are in addition to the following existing hourly life limits which are specified in Detroit Diesel Allison Commercial Service Letter CSL-120.

TURBINE WHEEL LIFE LIMIT, HOURS Stage 1 9700 Stage 2 11000 Stage 3 9900 Stage 4 11000

Upon request of the operator, an FAA maintenance inspector, subject to approval of the Chief, Engineering and Manufacturing Branch, Great Lakes Region, may permit alternate actions which provide equivalent levels of safety if the request contains substantiating data to justify them.

This amendment becomes effective January 28, 1981.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E-282](https://openairdocs.org/tcds/E-282): Rolls-Royce Corporation; names 5 of 9 models: 501-D13, 501-D13E, 501-D13A, 501-D13H, 501-D13D

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 9 (0 by airframe model, 9 by engine model)
- Makers: Convair 6, Lockheed 3

Models with the most aircraft:

- [Allison 501-D13 series](https://openairdocs.org/engine/allison-501-d13-series): 9 aircraft (engine model)

All 1 models: https://openairdocs.org/ad/81-03-02/models.md
Every aircraft: https://openairdocs.org/ad/81-03-02/aircraft.md

Its text cites no advisory circulars or STCs.

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