Aerospatiale AS355 accident near Rifle, Colorado, July 11, 2020
On July 11, 2020 at about 1:32 pm local time, a 1982 Aerospatiale AS355 (helicopter), registered N708AC, was destroyed in an accident during maneuvering (low-alt flying) near Rifle, Colorado. It was an aerial observation flight under general aviation rules (Part 91). 2 people were seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A loss of tail rotor effectiveness, the pilot’s subsequent loss of helicopter control, and collision with terrain.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 11, 2020 · about 1:32 pm local time
- Place
- Rifle, Colorado · map
- Type
- Accident
- Injuries
- 2 people were seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Aerospatiale AS355 F1, built 1982 · all AS355s on the register
- Registration
- N708AC · no longer on the register · serial 5167
- Damage
- Destroyed
- Flight
- Aerial observation flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot of the helicopter was maneuvering at a low altitude to conduct his first aerial observation flight of the day. The passenger, who was a camera operator for the flight, reported that the pilot began a hover over the electrical substation while they discussed a plan for the flight. While in a low altitude hover, the helicopter began swaying left and right, then spinning in a counterclockwise (left) direction. Shortly thereafter, the helicopter impacted the terrain. The pilot had no recollection of the accident. Witness observations indicated that the helicopter’s final impact was immediately followed by a postcrash fire that destroyed the helicopter. Postaccident examination of the helicopter and engine revealed no evidence of mechanical anomalies that would have precluded normal operation. The helicopter was operating at a gross weight of 5,040 lbs, and the maximum allowable gross weight is 5,291 lbs. The calculated density altitude was 6,566 ft mean sea level. The accident helicopter’s flight characteristics at the time of the accident would have included slow airspeed, a high-power setting, that were all conducive to a loss of tail rotor effectiveness (LTE), thus it is likely that the loss of control was the direct result of LTE.
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
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
- Loss of tail rotor effectiveness during maneuvering (low-alt flying) defining event
- Loss of control in flight during maneuvering (low-alt flying)
The NTSB's findings
- Environmental issues › Physical environment › Terrain › High elevation › Effect on operation
- Environmental issues › Physical environment › Terrain › Mountainous/hilly terrain › Not specified
- Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Prop/rotor parameters › Not attained/maintained
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 8,209 hours in all; 209 in this make and model; 37 in the last 90 days; 19 in the last 30 days; 8,209 as pilot in command
- Last flight review: August 6, 2019
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: rgt
- Injury: serious injuries
The aircraft
- Airframe total time: 11,210 hours
- Last inspection: inspection type not recorded, July 5, 2020
- Maximum gross weight: 5,291 lb
- Seats: 6
- Landing gear: fixed
- Engine 1: Rolls Royce (turboshaft); 0 hours total
- Engine 2: Rolls Royce (turboshaft); 0 hours total
- Fire on the ground
- Operator: Aircam National Helicopter Services INC
The flight
- Departed from: RIL Rifle CO at 1:30 pm
Weather at the time
- Light: daylight
- Wind: from 010° at 4 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 63°F (17°C), dew point 27°F (-3°C)
- Altimeter: 30.36 inHg
- Observation at 1:53 pm from RIL, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
14 documents, released by the NTSB on March 2, 2022. 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.