CEN20LA273 · Aerospatiale AS355 F1
Aircam National Helicopter Services Aerospatiale AS355 F1 · Accident: loss of tail rotor effectiveness while maneuvering
From Garfield County Regional Airport (RIL) to an unrecorded destination
Event
- NTSB case
- CEN20LA273
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Aerospatiale AS355 F1
- Aircraft type
- Aerospatiale AS355
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N708AC
- Onboard fatalities
- Unknown
- Route
- From Garfield County Regional Airport (RIL), Rifle, COTo not recorded
- Aircraft age
- About 38 years (built 1982)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Maneuvering · low-altitude flying
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Loss of tail rotor effectiveness
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Aircraft › Aircraft oper/perf/capability
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
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.
Probable cause
A loss of tail rotor effectiveness, the pilot’s subsequent loss of helicopter control, and collision with terrain.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN20LA273
- Event ID
- 20200711X95026
- Case number
- CEN20LA273
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, cause areas. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: a332d90e7361832e0e2e33260fc632b157a1cb65dfb230a96060cea863ff54e1; retrieved 2026-09-16T12:05:18.424Z.