Probable cause
The pilot's inability to maintain directional control during the landing roll due to a flat tire.
NTSB analysis
The pilot of the weight-shift control trike reported that, while landing, the trike touched down and started to oscillate back and forth. Subsequently, the trike rolled over, which resulted in substantial damage to the wing and the wing mast.
According to the pilot, after the accident he observed the right rear tire was flat and would not inflate during the postaccident examination. No other preaccident mechanical failures or malfunctions with the trike that would have precluded normal operation. It is likely the tire was deflated during touchdown, and the additional drag generated by the flat tire likely contributed to the oscillations during landing.
Text from the NTSB. Open the NTSB docket for WPR26LA175 for the full record.
Event
- Date
- May 2, 2026
- Type
- Accident
- Place
- Prineville, Oregon
- Nearest airport
- Prineville (S39)
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Cosmos PHASE II
- N-number
- N145W
- Category
- Weight-shift
- Year built
- 2003
- 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.