Turboprops vs piston twins

[colombatto]

Apart from purchase costs, they say that running a turboprop (such as a Cheyenne) can be almost twice as expensive than a piston twin (such as a Cessna 421).

Does anyone have experience in running the two types of aircraft?


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[cjrucker]

Turbines are great airplanes for reliability. If you can afford the admission price of a turbine, the extra costs of running it don't bother you too much. Comparing similar turbine and piston airplanes, you see that the turbine costs at least twice as much for modestly improved performance. The two airframes that are most comparable are the C421 and the 425 (Conquest 1) The conquest is considerably faster, but it should be at over a million dollars. You can get a similar C model 421 that admittedly goes 75 knots slower, but burns 40% as much fuel, and costs less than 400K. An older B model in reasonably good shape can be had for the low 200's.

the other airframe that is a close comparison is the Piper Cheyenne l and its piston precurser the Pressurized Navajo. Cheyennes in reasonable shape start at 500K while the Pa 31p are relative bargains, for sale all day at 150k. (I own one so you know where my allegiances lie). But remember that the purchase price in this class of airplane is only a beginning. To reengine this airplane (both sides and both props) is about 110,000. And you have to expect annuals in the 10,000 range every 2 or three years. (but overhauling two PT6's will run 400,000 smolians)

Again the Cheyenne l pumps out 450 horsepower compared with 425 for the P-Navajo. So there is not a great deal of difference in performance. Obviously I think the P Navajo is a steal if you understand that maintenance is going to be expensive. But not as expensive as those PT6s.


Casey