Probable cause
The failure of the right propeller position to correspond to the throttle change when moved to the beta position for reasons that could not be determined based on available evidence.
NTSB analysis
The pilot reported that the approach and landing flare were normal; however, as he moved both throttles to the beta position, it appeared that the left propeller went into the beta position while the right one did not. This resulted in a course deviation and runway excursion to the left, which led to the separation of the right main landing gear and substantial damage to the right wing.
The National Transportation Safety Board was unable to conduct a follow-up examination, as the airplane has been sold and a chain of custody had been compromised. As a direct result of the airplane not being able to be examined, the cause of the right propeller failure to correspond to the throttle movement to the beta position is undetermined.
Text from the NTSB. Open the NTSB docket for WPR20LA054 for the full record.
Event
- Date
- Dec 30, 2019
- Type
- Accident
- Place
- Big Piney, Wyoming
- Nearest airport
- Miley Memorial Field (BPI)
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Mitsubishi MU2B
- N-number
- N43866
- Category
- Airplane
- Year built
- 1980
- Damage
- Substantial
- Operating rule
- Part 91 (general aviation)
- Purpose of flight
- Personal
From the NTSB aviation accident database: N-registered aircraft, events since 2008, data through Oct 28, 2026. The file is published monthly, so the latest weeks are incomplete and recent records can change. The official source is the NTSB aviation investigation search. CheckAero is independent and not affiliated with the NTSB.