For small flight schools, even those with a dozen airplanes, the cost of airframes is a big economic driver. But for the mega schools like Embry Riddle and the University of North Dakota, price isnt a deal breaker. Maintenance cost and dispatch reliability loom large because the schools fly thousands of hours.
Given that aerodiesels burn three gallons an hour less than Lycomings, the potential savings alone ought to make diesels an easy sell, right? Not necessarily. Both schools told us theyve examined the potential of diesel-powered aircraft, but thus far havent been impressed enough to convert their existing fleet or order new J-TA Skyhawks from Cessna.
Why not? Purchase price is not a big driver for us, says Embry Riddles Pat Anderson. Maintenance costs are a much bigger factor, he told us. He declined to say what the maintenance-to-flight-hour ratio is on 172s, but we suspect its similar to UNDs 0 .24 per flight hour. In other words, eight hours of flight-which many school airplanes do every day-will eventually require two hours of maintenance. Diesel airplanes may do better than that, but bad experiences with problem airplanes live forever. The school network has vivid institutional recall of early problems Diamond had with the Thielert-powered DA42. UNDs Dan Kasowski also recalls issues the school had with a fleet of DA20s 20 years ago then debuting with Continentals new IO-240.
They had a ton of growing pains and we were in the middle of it. Well never do that again. I want a proven product. I dont want to buy anything lower than serial number 100, he said.
And while Redbird reports good dispatch reliability with its small fleet of converted 172s and lower maintenance incidence than with the Lycoming-powered versions, the big fleet buyers may take more convincing.