Probable cause
Foreign object damage sustained to the main rotor blades due to aerial tree trimming.
NTSB analysis
While conducting an aerial tree-trimming flight with an external load aerial saw, the pilot heard a loud “thump” and felt a collision. A heavy vibration was felt, and the pilot landed in a nearby cornfield without further incident. Upon landing substantial damage was found to the main rotor blades with embedded pieces of tree bark and vegetation found in the blades. The pilot reported that there were no mechanical malfunctions that contributed to the accident. The aerial saw was suspended about 120 ft below the helicopter. The operator noted that this distance is normally adequate to prevent foreign object damage (FOD) to the main rotor blades.
Text from the NTSB. Open the NTSB docket for CEN20CA334 for the full record.
Event
- Date
- Aug 5, 2020
- Type
- Accident
- Place
- Delia, Kansas
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Hughes 369
- N-number
- N104SU
- Category
- Helicopter
- Year built
- 1977
- Damage
- Substantial
- Operating rule
- Part 133 (external load)
- Purpose of flight
- External load
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.