Yes, the MU-2 has a history of being quite unforgiving at low speed with an inop engine. The FAA addressed this several years ago by adopting SFAR 108 which mandates special training and experience requirements applicable to MU-2 PICs. While training SFARs appear to have reduced the incidence of MU-2 loss of control accidents, it's not reasonable to expect all such occurrences to be eliminated by training requirements. The Robinson helicopter training SFAR is another similar example. It's similar to type rating training, but without the issuance of a type rating.
Given the high profile nature of Sen. Inhofe and the past history of MU-2 control loss accidents, I expect the NTSB will be especially interested in performing a detailed investigation of this crash and a review of the effectiveness of SFAR 108. (which IIRC, was instituted at least in part as a result of NTSB recommendations made in past MU-2 accidents)
The TPE-331 engines installed on this aircraft rely upon a negative torque sensing system (NTS) to dump oil pressure from the prop dome to prevent the prop from driving the direct drive turboprop engine. If an engine stops producing positive torque to the prop in flight, the NTS system will release the oil from the prop dome and the prop will increase pitch progressively towards the feather position over a period of time. While this happens automatically, it is not an auto feather system. Fully feathering the prop is accomplished by pulling the stop/feather handle. This operates the prop oil dump and fuel shutoff valves by cable and mechanical linkage in the MU-2. (the FSOV is electrically operated for start and for normal shutdown)
Of course as the investigation progresses, at least some of the elements of the accident will be uncovered and possibly made public. I have in mind several possible scenarios which could produce the results reported thus far, but time will tell how accurate these eyewitness reports were.
I usually don't engage in "condolences" on crash threads anymore, but I do feel something for Senator Inhofe's 50 years of involvement and his dedication to aviation. I hope there is enough evidence to at least find out with some degree of certainty what went wrong. To an aviation family like the Inhofes, at least that might be something...
westhawk