WPR19LA029 · BKF Backcountry Supercub
BKF Backcountry Supercub · Accident: loss of engine power (total) during initial climb
From Casper-Natrona County International Airport (CPR) to Casper-Natrona County International Airport (CPR)
Event
- NTSB case
- WPR19LA029
- 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
BKF Backcountry Supercub
- Aircraft type
- BKF BACKCOUNTRY SUPERCUB
- Category
- Airplane
- 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
- N59BK
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Casper-Natrona County International Airport (CPR), Casper, WYTo Casper-Natrona County International Airport (CPR), Casper, WY
- Aircraft age
- Built the same year (2018)
- 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
- Initial climb
- 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
- Substantial
Cause areas
- Aircraft › Aircraft power plant
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The commercial pilot was flight testing the airplane to evaluate an experimental diesel engine reduction gearbox. During the takeoff, as the airplane climbed above 500 ft above ground level, the pilot increased engine power, but a total loss of engine power occurred shortly afterward. The pilot initiated a left descending turn to return to the runway. During the landing sequence, the airplane had a high descent rate. The airplane touched down hard, resulting in the separation of the left main landing gear axle and substantial damage to the left wing lift strut. Postaccident examination of the engine reduction gearbox found that two propeller shaft bearings inside the reduction gearbox seized, causing the total loss of engine power.
Probable cause
The seizure of two bearings in the reduction gearbox, resulting in the total loss of engine power. Contributing to the accident was a high descent rate which resulted in a hard landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR19LA029
- Event ID
- 20181119X70304
- Case number
- WPR19LA029
- 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: 972d0034fab62a07b320e8297fc64f2af1a47691534b026008fe4330c6d74f06; retrieved 2026-09-16T08:26:40.295Z.