WPR17LA043 · Robinson Helicopter Company R44 II
Robinson Helicopter Company R44 II · Accident: loss of lift on approach
From Fullerton Municipal Airport (FUL) to Mt. Baldy, CA
Event
- NTSB case
- WPR17LA043
- 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
- N324RS
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Fullerton Municipal Airport (FUL), Fullerton, CATo Mt. Baldy, CA
- Aircraft age
- About 13 years (built 2003)
- 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
- Approach
- 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 lift
- 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
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The commercial pilot planned to land the helicopter at the top of a high mountain peak. Three passengers were onboard, and the helicopter was loaded just below its maximum gross weight. The enroute climb was uneventful, and after reaching the peak, the pilot performed an orbit over the landing site. While surveying his landing options, the helicopter's low rotor rpm warning horn sounded, and he corrected by lowering the collective and increasing engine power. The horn stopped, and he continued to circle the area while reviewing an engine limit manifold pressure chart and determining that he had enough engine power available to proceed.
Hikers were close to his intended landing area, so he initiated an approach with a tailwind toward the lower face of a ridgeline with the intention of turning back to land into the wind. As he approached the landing spot, the low rotor rpm horn sounded again, and he lowered the collective. The helicopter descended rapidly, and due to terrain, there was no escape path, so he warned the passengers to brace for impact. The helicopter landed hard and sustained substantial damage.
The helicopter was operating at the upper limit of its performance capabilities at the reported gross weight and calculated density altitude. Performance charts indicated that the helicopter would not have been able to hover at that altitude, and as such, a successful landing, while not impossible, would have been challenging. The activation of the warning horn during the initial orbit would have been another indication to the pilot that there was limited engine power available for landing.
The pilot reported no preimpact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation, and the accident is consistent with the pilot's failure to maintain rotor rpm while operating near the helicopter's performance limits.
Probable cause
The pilot's failure to maintain main rotor speed during a low orbiting approach over a confined mountainous area. Contributing to the accident was the pilot's decision to attempt to land in an area that did not allow for a safe exit path under conditions near the limit of the helicopter’s performance capability.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR17LA043
- Event ID
- 20161230X15938
- Case number
- WPR17LA043
- 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: df4f62f92d32ea9aa6a718e2d62202f4b1bb924ce0ce22d56c773142f653abc0; retrieved 2026-09-16T04:55:21.232Z.