WPR10LA127 · Hiller UH-12E
Jeff Streeter Motor Sports Hiller UH-12E · Accident: powerplant system/component malfunction/failure on approach
From Los Banos, CA to Los Banos, CA
Event
- NTSB case
- WPR10LA127
- 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
Hiller UH-12E
- Aircraft type
- Hiller UH-12
- 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
- N36MV
- Operator
- Jeff Streeter Motor Sports
- Onboard fatalities
- Unknown
- Route
- From Los Banos, CATo Los Banos, CA
- 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 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
- Approach · VFR pattern final
- 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
- Powerplant system/component malfunction/failure
- 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 power plant
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 had just completed an aerial application flight and was returning to land. As he approached the landing area, he began to apply power, but the engine did not respond. He continued to twist the throttle, but it felt loose with no resistance and the engine speed did not change. He aborted the landing approach and performed a run-on landing in a field; during the approach the engine speed began to decrease and the helicopter landed hard, causing substantial damage to the tail boom and lower fuselage. Postaccident examination revealed that the throttle control attach fitting located in the aft section of the collective control had become separated. The nuts and bolts attaching the fitting were not located. The lack of witness marks on the throttle fitting indicates that either the attachment bolt failed or rapidly unscrewed from its associated nut. The disconnection resulted in a loss of engine control and subsequent partial loss of engine power. The last annual inspection occurred 11 months and 250 flight hours prior to the accident.
Probable cause
A partial loss of engine power due to a failure of the throttle interconnect hardware, which resulted in a hard landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR10LA127
- Event ID
- 20100202X95507
- Case number
- WPR10LA127
- 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. 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: 099c8c17a96dc9eea968b6913c24ff1b9fbe70571120ee7cfd46b6cf1918b71a; retrieved 2026-09-15T13:39:48.766Z.