80-14-13 DETROIT DIESEL ALLISON: Amendment 39-3820. Applies to Model 501-D13, 501-D13A, 501- D13D, 501-D13E, and 501-D13H engines equipped with 1st stage turbine wheels with part numbers 6844061 and 6847111. Compliance is required as indicated. To prevent disc failures due to fatigue, these discs are to be removed from service depending upon the spline fit interference or reaching the hourly limitation. The schedule for wheel removal is as follows:
(1) Spline fit - 0.000 to 0.0009T
(a) Wheels which have greater than 15,800 cycles on the effective date of this AD are to be removed from service within 200 cycles.
(b) Wheels which have less than 15,800 cycles on the effective date of this AD are to be removed from service before they accrue 16,000 cycles.
(2) Spline fit - .001T - .0025T
(a) Wheels which have greater than 18,550 cycles on the effective date of this AD are to be removed from service within 450 cycles.
(b) Wheels which have less than 18,550 cycles on the effective date of this AD are to be removed from service before they accrue 19,000 cycles.
(3) It is the operator's responsibility to obtain wheel-to-shaft spline fit data from the Overhauler to determine which spline fit applies to their respective turbine or turbines. Only wheels that have conformed to a .001T min. fit throughout their entire utilization history qualify for paragraph (2) above.
(4) Wheels which have 9700 hours of service prior to accuring 16,000 cycles (spline fit 0.000 to 0.0009T) or 19,000 cycles (spline fit .001T - .0025T) shall be removed from service.
This amendment becomes effective July 10, 1980.