- Date
- December 23, 2025, 15:43 local (23:43 UTC)
- Place
- Yacolt, WA · Approx 5 miles? from WA87
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N186BGZenith 750
- Defining event
- Enroute-cruise: Loss of engine power (total)
- Weather
- Visual (VMC) · Day
- Status
- Completed · report April 14, 2026
- Report
- Approved by Office Director
- Investigation class
- Class 4 - Basic report with no Prelim publish
- NTSB office
- Western Pacific Region
- Parties
- Federal Aviation Administration
- FAA report
- 20251223019739A
- Case key
- 202221
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
A loss of engine power for undetermined reasons.
Findings · 1
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Analysis
The pilot was returning to the airport while conducting a phase 1 test flight in an experimental airplane when he detected a burning odor. He scanned the engine instruments which all showed normal indications. Shortly after, about 4 miles from his home airport, the engine shut down. He reported his position and intentions on the local radio frequency and initiated a forced landing to a down sloping field. During the landing roll the airplane impacted terrain, sustaining substantial damage to the fuselage and wings. The pilot also reported that after he exited the airplane, he didn’t see any oil or water dripping from the cowling or oil spray on the windshield. At the time of the accident the airplane had accrued 16 hours of operation. The FAA conducted a postaccident examination of the experimental airframe and engine, which revealed no preimpact mechanical malfunctions or failures that would have precluded normal operation. The pilot further reported that he found an odor from one of the engine control unit (ECU) connectors, although a review of the electrical system by the FAA did not reveal any evidence of electrical system damage. The ECU was sent to the engine manufacturer and tested normally with a functioning engine. Based on this information, the reason for the loss of engine power could not be determined.
Aircraft
- Registration
- N186BG
- Reported as
- Zenith 750 (Super Duty)
- Category
- Airplane, amateur-built
- Serial number
- SD75-11850
- Built
- 2025
- Airframe hours
- 16
- Engine
- Viking Aircraft Engines 195T, 195 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- Condition · August 21, 2025 · 16 hours before
- Departed
- WA87 · Battle Ground, WA
- Airport
- WA87 · Parkside Airpark
- Equipment
- Video recording device, ADS-B, Electronic primary flight display
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 71
- Injuries
- None
- Certificate
- Commercial
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane, Helicopter
- Medical
- BasicMed, With waivers/limitations
- Last flight review
- September 14, 2025
- Seat
- Left
- Flight hours
- 6,400 total · 25 in this make and model · 5,560 as pilot in command · 15 in the last 90 days · 3 in the last 30 days · 1 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Calm
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 46 °F, dew point 39 °F
- Altimeter
- 29.75 inHg
- Icing
- Unknown
- Turbulence
- Unknown
- Observed at
- KVUO, 17 nm away
- METAR
- METAR KVUO 232253Z AUTO 00000KT 10SM CLR 08/04 A2975 RMK AO2 SLP076 T00780039
Docket · 5
The files NTSB released with the investigation on April 14, 2026, on NTSB’s docket system: statements, records, photos and specialists’ reports. 7.2 MB in all.
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.