Probable cause
The pilot's failure to maintain clearance from the power transmission lines. Contributing to the accident was the unmarked power transmission lines.
NTSB analysis
The helicopter impacted unmarked power transmission lines as the pilot maneuvered at a low altitude over a river. The helicopter impacted the river and separated into several pieces. The pilot and his passengers were not injured and were rescued by nearby boaters.
Text from the NTSB. Open the NTSB docket for CHI08CA177 for the full record.
Event
- Date
- Jul 4, 2008
- Type
- Accident
- Place
- Ottawa, Illinois
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Robinson R44 II
- N-number
- N31138
- Category
- Helicopter
- 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.