Pilot Debrief

COSMOS PHASE II near Prineville, OR — 2026-05-02

Final reportWPR26LA175
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Date
2026-05-02
Location
Prineville, OR, USA
Airport
S39
Aircraft
COSMOS PHASE II
Registration
N145W
Category
Trike
Highest injury
None
Fatalities
0

Probable cause

The pilot's inability to maintain directional control during the landing roll due to a flat tire.

NTSB narrative

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.

NTSB coding

Evidence available

  • Photos
  • 2 docket documents
View NTSB final reportView NTSB docket

Docket documents2

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