DEN03LA020 · Aerospatiale AS-350BA
Crew Concepts Aerospatiale AS-350BA · Accident: loss of control in flight on approach
From Monticello, UT (no airport) to an unrecorded destination
Event
- NTSB case
- DEN03LA020
- 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 AS-350BA
- Aircraft type
- Aerospatiale AS-350
- 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
- N20840
- Operator
- Crew Concepts
- Onboard fatalities
- Unknown
- Route
- From Monticello, UT (no airport)To not recorded
- Aircraft age
- Not recorded
- 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 133: Rotorcraft Ext. Load
- 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
- Approach
- First occurrenceThe 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 control in flight
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Pilot in command › Rotor RPM, not maintained
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
According to the pilot, he had moved approximately 80 bags of seismic sensor cable earlier that morning with no problems. At approximately 1120, the pilot stopped operations to change lines. He proceeded to pick up five bags and was en route to the drop off point. During the approach to the north, the pilot "noticed that the Nr (rotor rpm) was high at roughly 400 rpm as [he] turned to the west." As the pilot slowed down, he added collective to reduce the rotor speed. The rotor rpm began to slow, at which point the pilot lowered the collective and applied forward cyclic to maintain forward airspeed. The rotor speed continued to decrease and the "low rotor speed warning horn" sounded. The pilot lowered the collective and flared, at which point the bags contacted the ground. The pilot then "noticed that the Nr was low" at approximately 320 rpm. The pilot "zeroed the airspeed, pumped the collective once[,] trying to slow the rate of decent and pulled up on the collective," just before impacting the ground. The helicopter settled onto the load beneath it, and subsequently rolled over on its right side causing substantial damage. An examination of the helicopter revealed no anomalies.
Probable cause
the pilot's failure to maintain rotor rpm. A related factor was the presence of an object in the path during the touchdown.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN03LA020
- Event ID
- 20021209X05577
- Case number
- DEN03LA020
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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, coordinates. 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: d55ace44bfebeb8d3821777112f2a1ab32e08a60b3a34fff3616d35bb44905b3; retrieved 2026-09-21T19:34:17.958Z.