Robinson R44 accident near Bella Vista, California, July 3, 2017
On July 3, 2017, a 2008 Robinson R44 (helicopter), registered N488AS, was substantially damaged in an accident during maneuvering (low-alt flying) near Bella Vista, California. It was a personal flight under general aviation rules (Part 91). 2 people were seriously injured and 2 people had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A partial loss of engine power during low-altitude maneuvering for reasons that could not be determined because postaccident examinations of the engine and airframe revealed no evidence of any preaccident mechanical malfunctions or failures that would have precluded normal operation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 3, 2017
- Place
- Bella Vista, California · map
- Type
- Accident
- Injuries
- 2 people were seriously injured and 2 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Robinson R44 II, built 2008 · all R44s on the register
- Registration
- N488AS · no longer on the register · serial 12538
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The commercial pilot reported that, while making a left descending turn in the helicopter about 75 to 100 ft above a pond to set up for landing to a field, he heard three "pops," followed by the low rotor horn sounding and the caution light illuminating. The pilot assumed that the engine had lost power, and he immediately and abruptly lowered the collective, pulled aft on the cyclic, and rolled the throttle to full open. To avoid obstructions, he steepened the right turn. Realizing that the rotor rpm was below 50% and that the helicopter would not reach the field, he subsequently landed the helicopter on the pond; it then sank. The pilot was unsure if the engine was running or not. Postaccident airframe and engine examinations revealed no evidence of any preaccident mechanical failures or malfunctions that would have precluded normal operation. The reason for the partial loss of engine power could not be determined.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Loss of engine power (partial) during maneuvering (low-alt flying) defining event
- Abrupt maneuver during maneuvering
- Attempted remediation/recovery during maneuvering
- Off-field or emergency landing during landing
The NTSB's findings
- cause Not determined › Not determined › (general) › (general) › Unknown/Not determined
Pilot
- Certificate: commercial pilot
- Ratings: rotorcraft: gyroplane; rotorcraft: helicopter
- Flight time: 502 hours in all; 350 in this make and model; 350 as pilot in command
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: frt
- Injury: minor injuries
Passenger
- Seat: left
- Injury: serious injuries
Passenger
- Seat: left
- Injury: serious injuries
Passenger
- Seat: rgt
- Injury: minor injuries
The aircraft
- Airframe total time: 2,143.8 hours
- Last inspection: annual inspection, June 1, 2017; 26 hours since
- Maximum gross weight: 2,500 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming IO-540-AE1A5 (piston); 2,144 hours total
The flight
- Departed from: RDD Redding CA
- Destination: RDD Redding CA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 150° at 14 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 100°F (38°C), dew point 55°F (13°C)
- Altimeter: 29.79 inHg
- Observation at 11:53 pm from KRDD, 11 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 2 | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
14 documents, released by the NTSB on December 14, 2018. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.