Probable cause
The crew leader's decision to throw a chainsaw bar into the moving arc of the main rotor blade.
NTSB analysis
The pilot reported that, after landing on an elevated helicopter deck and reducing the rotor RPM, he signaled for the brush cutting ground crew leader to approach the helicopter to collect additional chainsaw bars that were being dropped off. He added that, the crew leader indicated that two of the three chainsaw bars were not the correct bars needed, and then threw an incorrect bar away from the helicopter. Subsequently, the bar impacted a main rotor blade, which resulted in substantial damage.
The pilot reported that the brush cutting crew had been briefed before operations on gear security, rotor awareness, and safe practices when working around the helicopter. The crew leader admitted to a lapse in judgment brought on by stress and frustration.
The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.
Text from the NTSB. Open the NTSB docket for ANC20CA068 for the full record.
Event
- Date
- Jul 10, 2020
- Type
- Accident
- Place
- Ketchikan, Alaska
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Robinson R44
- N-number
- N878CB
- Category
- Helicopter
- Year built
- 2004
- Damage
- Substantial
- Operating rule
- Part 135 (charter and commuter)
Other records under this N-number
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.