Turbine question

[DeltaDeltaDelta]

I've noted that turbine conversions of piston planes have become popular
(Turbine Bonanza, JetProp, Turbine Otter...). While reading the pireps of
these planes in Private Pilot, I saw that in most of these planes, the
turbine appeared to be turned "backwards", ie with the rear nozzle turned
toward the prop and the exhaust pipes near the spinner. Why is this so?

Triple Delta

[Ditch]

>with the rear nozzle turned
>toward the prop and the exhaust pipes near the spinner. Why is this so?

The engines they use for the conversion are typically the Rolls Royce whatever
(formerly the Allison 250). These are reverse flow, free spinning turbines.
Basically, the air enters the front and is routed thru the engine from back to
front.
The PT-6 is the same way (what I am currently flying). The Garretts (Or
whatever they are called today) are direct drive turbines and the airflow is
front to back.




-John
*You are nothing until you have flown a Douglas, Lockheed, Grumman or North
American*