WPR19LA019 · Bell 47G 3B1
Bell 47G 3B1 · Accident: loss of engine power (total) during autorotation
From Wichita Valley Airport (F14) to Wichita Valley Airport (F14)
Event
- NTSB case
- WPR19LA019
- 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
Bell 47G 3B1
- Aircraft type
- Bell 47
- 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
- N1159W
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Wichita Valley Airport (F14), Wichita Falls, TXTo Wichita Valley Airport (F14), Wichita Falls, TX
- Aircraft age
- About 54 years (built 1964)
- 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
- Autorotation
- 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 engine power (total)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Aircraft › Aircraft power plant
- Not determined › Not determined
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot reported that the purpose of the flight was to practice emergency procedures with a certified flight instructor (CFI). After completing four uneventful autorotations, they climbed the helicopter to an altitude of about 1,500 mean sea level and turned onto the final approach leg of the traffic pattern to conduct a ‘hydraulics off’ approach. Once established on final approach, the CFI reached down to turn off the hydraulic switch, and the engine lost complete power. The pilot immediately gave the flight controls to the CFI, and he prepared for an autorotation in a nearby field. During the descent, the helicopter impacted powerlines before it landed hard. The main rotor blade severed the tailboom, and the helicopter spun before it came to rest on its side.
The CFI confirmed that when he reached down to turn off the hydraulic switch, the engine lost complete power. He mentioned that the hydraulic switch is on the lower console, and he was unaware of any nearby switches that would have turned off the engine.
During a postaccident examination no anomalies were noted with the engine that would have precluded normal operations. The instrument panel was removed; the electrical wires were examined, and no abnormalities were noted. At the accident site, the ignition switch was found in the BOTH position. The ignition switch positions (RIGHT, LEFT, and BOTH) were tested and functioned normally. However, when the key was in the LEFT or RIGHT position, movement of the key would temporarily ground the switch. It was noted that a long keychain attached to the key extended over the hydraulics switch when the key was in the ignition.
It is possible that the CFI moved the keychain away from the hydraulic switch and, in doing so, could have caused the ignition switch to temporarily ground. Subsequently, the engine would lose complete power with no warning. However, this scenario would require the ignition switch to be either in the LEFT or RIGHT position because moving the ignition key while in the BOTH position did not cause the switch to temporarily ground. Since there is no evidence of the switch being in a position other than BOTH, the investigation was unable to determine the reason for the total loss of engine power.
Probable cause
A total loss of engine power for reasons that could not be determined based on the available information.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR19LA019
- Event ID
- 20181104X15925
- Case number
- WPR19LA019
- 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: ef17fe9a2722c8b640ff688001a4e28df938e53553f797e125c8e8c10329f94b; retrieved 2026-09-16T08:24:42.730Z.