STC Applications Raise Issues

Anyone who’s owned a vehicle with one knows that a diesel engine is a different animal, requiring different care and feeding. Well, the same goes for aircraft applications and the FAA has come out with a list of special conditions that must be satisfied before the switch is made from 100LL to Jet-A. And while you’d expect there to be some regulatory requirements, the list is (so far) pretty long and deals with some rather esoteric distinctions between the two types of mills. Although aircraft diesels have been flying in several types of GA aircraft for almost a decade, supplementary type certificates seem to be fairly rare. According to our research, the U.S. has approved an STC for use of the Thielert 1.7-liter diesel in later model Cessna 172s, while the Thielert is also approved for Piper Cherokees in Europe. Europe has also approved the SMA diesel for conversion of the Cessna 182.