CHI98LA312 · Hiller UH-12E
Hiller UH-12E · Accident: loss of engine power while maneuvering
Event
- NTSB case
- CHI98LA312
- 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
- 0
- 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
- N88782
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo 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 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 · aerial application
- 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 engine power
- 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
- Fuel system › Starvation
- Pilot in command › Fuel management, inadequate
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The aircraft experienced a total loss of engine power while maneuvering during agricultural spraying. The aircraft impacted terrain during a forced landing. Examination of the engine by a Federal Aviation Administration Inspector showed the engine to rotate and to have compression in all cylinders. Electrical continuity was established from the magnetos and through the harness. There was no fuel found in the fuel line connecting the fuel tank to the engine driven pump. The engine driven and electric fuel pumps rotated and were then disassembled but damage was found on the impeller of the fuel pumps. The carburetor bowls contained 1/3 fuel. Approximately three gallons of fuel was drained from the helicopter fuel tank with no external leakage visually present. The fuel tank port is located at the forward end of the fuel tank. The Hiller UH-12E Flight Manual states, 'Operating with fuel indicator in the yellow arc during sideward or rearward flight may result in loss of power'. The yellow arc indicates a fuel range from 0 to 2.9 gallons, 0 to 11 liters, 0-17 lbs. of fuel. The Hiller UH-12E Flight Manual Supplement states, 'Consideration should be given to hoisting loads off the ground vertically as pulling or dragging loads off in other than a vertical direction can cause the helicopter to exceed the certified normal flight body-angle and unusable fuel envelope'.
Probable cause
The pilot mismanaged the fuel which led to fuel starvation and subsequent loss of engine power.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI98LA312
- Event ID
- 20001211X10802
- Case number
- CHI98LA312
- 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. 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: ae6f132ea1bb9298e072d7f3af8c9d9d91e5111afce060cb0f630abd04c78ad9; retrieved 2026-09-21T11:21:39.537Z.