om a distance, N73FR looks like any other 20-something-year-old Skyhawk. Upon closer inspection, the differences loom large. Whats a constant-speed, three-blade prop doing on a 172? And isn’t that exhaust pipe a little skinnier than normal? A couple of other differences are apparent, such as the cowling-mounted inspection port for gearbox lubricant and new fuel-filler caps next to placards calling for Jet A. And the thing smells…oily, like kerosene, not the sweet scent of avgas.

Gearbox lubricant? Jet fuel? What the heck is this, a turboprop Skyhawk? Nope, its a Thielert Centurion 1.7 aerodiesel conversion of the Skyhawk, one of the first in fleet service in the U.S. and perhaps the leading edge of the inevitable diesel revolution as avgas roller coasters between $3 and $7 a gallon. We recently flew the airplane it flies like a Skyhawk, were happy to report but thats not the real story. The real story is that this conversion is in work-a-day commercial service and the company that paid for it believes that the economics pencil out to be superior to the Lycoming engine the Skyhawk left the factory with.

Diesel Skyhawk: Conversions Hit the U.S.

From a distance, N73FR looks like any other 20-something-year-old Skyhawk. Upon closer inspection, the differences loom large. Whats a constant-speed, three-blade prop doing on a 172?

Why Convert?

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