| Crash location | Unknown |
| Nearest city | Rapid City, SD
44.080543°N, 103.231015°W |
| Tail number | N64MD |
|---|---|
| Accident date | 09 Feb 1990 |
| Aircraft type | Mitsubishi MU-2B-60 |
| Additional details: | None |
FAILURE OF THE PILOT TO MAINTAIN ADEQUATE AIRSPEED (VMC), WHICH RESULTED IN A LOSS OF AIRCRAFT CONTROL. A FACTOR RELATED TO THE ACCIDENT WAS: FATIGUE FAILURE OF A COUPLING SHAFT IN THE #1 ENGINE, WHICH RESULTED IN LOSS OF POWER IN THAT ENGINE.