WPR24LA299 · Williams Helicopter Corp UH-1H
A&p Helicopters Williams Helicopter Corp UH-1H · Accident: loss of control in flight while maneuvering
From Richvale Airport (07CL) to an unrecorded destination
Event
- NTSB case
- WPR24LA299
- 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
Williams Helicopter Corp UH-1H
- Aircraft type
- Williams UH-1
- 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
- N710WD
- Operator
- A&p Helicopters
- Onboard fatalities
- Unknown
- Route
- From Richvale Airport (07CL), Richvale, CATo not recorded
- Aircraft age
- About 59 years (built 1965)
- 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 137: Agricultural
- 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 · hover
- 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 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
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot of the helicopter reported that while repositioning closer to the loading equipment, the helicopter experienced collective bounce. He attempted to maneuver the helicopter to avoid equipment and personnel; however, control was lost and the helicopter impacted terrain. The operator reported that there were no preaccident mechanical malfunctions or failures that would have precluded normal operations. The operators manual for the helicopter stated, in part, “Collective bounce is a pilot Induced vertical oscillation of the collective control system when an absolute friction (either pilot applied, or control rigged) is less than seven pounds. It may be encountered in any flight condition by a rapid buildup of vertical bounce at approximately three cycles per second. The seventy of the oscillation is such that effective control of the helicopter may become difficult to maintain. The pilot should apply and maintain adequate collective friction in all flight conditions.”
Probable cause
The pilot’s failure to set collective friction which resulted in collective bounce and subsequent loss of control.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR24LA299
- Event ID
- 20240909195085
- Case number
- WPR24LA299
- 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, coordinates, 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: 28af6b663da1eff2ee6f595aa04f28b6f7361d53ffbded0c2a2993edebf633e1; retrieved 2026-09-16T19:14:57.430Z.