In the United States, even though the MU-2 is a very high performance airplane with complicated systems that has to be flown like a jet, because it weighs less than 12,500 pounds there was no requirement for a pilot to get any training or pass a check ride before flying one. Any multi-engine-rated pilot could jump in an MU-2 without even getting a checkout and legally take off. For a pilot used to flying a Cessna 402 or a Navajo, an airplane that climbs at 2,000 fpm, cruises at 300 knots at FL 300 and descends at 4,000 fpm is going to be more than a challenge. The MU-2 also has some operating features and characteristics that require a response opposite of what a piston twin pilot would do. This wouldn’t have been so bad if it had been hard to get your hands on an MU-2, but because of its bad reputation, an MU-2 was about the least expensive turboprop, with airplanes available for the price of a high performance single-engine airplane.