SEA04LA071 · Keller Prospector FK1
Keller Prospector FK1 · Accident: total loss of engine power (non-mechanical) en route
From Stevensville Airport (32S) to Jackpot Airport/Hayden Field (06U)
Event
- NTSB case
- SEA04LA071
- 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
Keller Prospector FK1
- Aircraft type
- Keller PROSPECTOR FK1
- 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
- N5XK
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Stevensville Airport (32S), Stevensville, MTTo Jackpot Airport/Hayden Field (06U), Jackpot, NV
- 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 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
- En route · cruise
- 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
- Total loss of engine power (non-mechanical)
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Tree(s)
- 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
- Pilot in command › Carburetor heat, not used
- Weather condition › Carburetor icing conditions
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
In a written statement the pilot reported that approximately 10 miles south of Lost Trail Pass he decided to turn back due to deteriorating weather ahead. The pilot stated that during the turn he lost track of the two other aircraft that made up the flight of three. The pilot stated he was "trying to locate [the] other two A/C [aircraft] to the exclusion of the engine instruments". The pilot stated that as the airplane reached the summit he added power "as I was too low." Concurrent with the increase in power, the engine quit. The pilot maneuvered the airplane in an effort to avoid rising terrain, however, during the maneuver the airplane collided with multiple trees eventually impacting terrain in an inverted position. The pilot rated passenger reported the weather conditions along the route of flight began to deteriorate, and the pilot-in-command of the accident airplane elected to return to Stevensville. The passenger reported that shortly after making the decision to return, the airplane's engine began to lose power. After losing power, the airplane stalled and collided with terrain. The pilot and pilot rated passenger both indicated the loss of power was the result of carburetor ice. The pilot was operating the airplane in moderate snow showers. The pilot's written report indicated the outside air temperature was approximately 35 degrees Fahrenheit.
Probable cause
The pilot's failure to apply carburetor heat in icing conditions which resulted in a loss of engine power while in cruise flight. Factors contributing to the accident are unsuitable terrain for an emergency landing , trees and mountainous terrain.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA04LA071
- Event ID
- 20040422X00502
- Case number
- SEA04LA071
- 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, 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: 4eb4bb4fdc9830f98dfd6fac5616a02ae459cd332c203cbd93b08645105d4d76; retrieved 2026-09-21T09:18:09.792Z.