CEN11CA325 · Robinson Helicopter Company R44 II
Colorado Helicopter Robinson Helicopter Company R44 II · Accident: settling with power/vortex ring state while maneuvering
From Rocky Mountain Metropolitan Airport (KBJC) to Rocky Mountain Metropolitan Airport (KBJC)
Event
- NTSB case
- CEN11CA325
- 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
Robinson Helicopter Company R44 II
- Aircraft type
- Robinson R44
- 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
- N921JM
- Operator
- Colorado Helicopter
- Onboard fatalities
- Unknown
- Route
- From Rocky Mountain Metropolitan Airport (KBJC), Denver, COTo Rocky Mountain Metropolitan Airport (KBJC), Denver, CO
- 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 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
- Settling with power/vortex ring state
- 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
- Aircraft › Aircraft oper/perf/capability
- Environmental issues › Conditions/weather/phenomena
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The helicopter was following participants in a downhill skateboard race in mountainous terrain. The pilot had just performed a left-pedal turn and the helicopter was facing upslope to the mountain. The low rotor warning sounded and the pilot lowered the collective and increased throttle. The pilot stated that the engine did not respond so he continued to lower the collective and looked for a place to land. During the forced landing on the downsloping terrain the helicopter came to rest on its nose, resulting in substantial damage to the main rotor, skid tubes, and tail boom. Postaccident examination of the helicopter, engine, and systems, revealed no anomalies. The density altitude was calculated to be 10,600 feet. The pilot calculated the in-ground-effect hover to be 8,500 feet pressure altitude, the out-of-ground-effect hover to be 5,000 feet pressure altitude, and estimated the gross weight to be 2,320 pounds.
Probable cause
The pilot’s decision to operate the helicopter at a high density altitude near terrain, which resulted in a settling with power condition.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN11CA325
- Event ID
- 20110509X10416
- Case number
- CEN11CA325
- 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. 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: ac42e6b8a5a692650c13026033b42653aa2fead3a2096b2f87fa33d6a70d6eeb; retrieved 2026-09-15T16:08:42.923Z.