Probable cause
The failure (disbonding) of a composite main rotor blade for undetermined reasons, leading to an immediate loss of control in flight during hover.
NTSB analysis
During a stationary low hover of the recently built experimental helicopter, it suddenly and without warning rotated rapidly in a counter-clockwise direction around its longitudinal axis, and immediately impacted the ground. The investigation determined that one of the main rotor blades had failed (disbonded), leading to an immediate loss of control in flight. The composite blade, which was designed specifically for use on one manufacturer's experimental helicopter, was being used on another manufacturer's experimental helicopter, as allowed by its experimental designation. Due to the lack of sufficient engineering, manufacturing, and testing data, the precise initiating factor of the disbonding event could not be determined.
Text from the NTSB. Open the NTSB docket for WPR09LA350 for the full record.
Event
- Date
- Jul 16, 2009
- Type
- Accident
- Place
- Sequim, Washington
- Nearest airport
- Sequim Valley (W28)
- Highest injury
- Minor
- Minor injuries
- 2
- Weather
- Visual (VMC)
- Light
- Day
Amateur-built ROTORWAY E
- N-number
- N3213K
- Category
- Helicopter
- Damage
- Substantial
- Operating rule
- Part 91 (general aviation)
- Purpose of flight
- Instructional
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.