- Date
- January 24, 2020, 09:56 local (17:56 UTC)
- Place
- Auburn, CA · Wooded terrain near hilltop
- Injuries
- 2 fatal, 1 serious
- Damage
- Destroyed
- Phase of flight
- Enroute
- Aircraft
- N50249Stinson V77
- Defining event
- Enroute: Loss of engine power (total)
- Weather
- Visual (VMC) · Day
- Status
- Completed
- Report
- Approved by Office Director
- Investigation class
- Class 3
- NTSB office
- Western Pacific Region
- Parties
- Federal Aviation Admnistration
- FAA report
- 20200124001799A
- Case key
- 100856
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 total loss of engine power due to a combination of mechanical engine anomalies. Contributing to the accident was inadequate maintenance that failed to identify the engine anomalies.
Findings · 5
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 departed on a local flight with two passengers. Several witnesses reported that they heard the airplane’s engine backfiring and sputtering and subsequently heard the engine quit. The surviving passenger, who was seated in the front right seat, stated that the engine lost power and there was nowhere to land. The airplane subsequently impacted heavily wooded terrain about 1 mile from the departure airport. Postaccident examination of the engine revealed that the No. 7 cylinder intake valve was stuck open. The No. 2 cylinder front spark plug was defective, and the Nos. 2- and 4-cylinders’ ignition wires were frayed, worn, and displayed arcing, which likely led to erratic operation or a lack of ignition in these two cylinders. The culmination of these issues most likely led to the engine running rough, backfiring, and subsequently losing total power. An annual inspection was accomplished on the airframe and engine about 2 months before the accident. General maintenance practices and the inspection should have identified the anomalies that were found during the postaccident engine examination.
Aircraft
- Registration
- N50249
- Reported as
- Stinson V77 (No Series)
- Category
- Airplane
- Serial number
- 77-458
- Engine
- Pratt & Whitney 985, 450 horsepower, reciprocating
- Damage
- Destroyed
- Flight
- Personal · Part 91
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · December 1, 2019
- Departed
- AUN · Auburn, CA
- Destination
- AUN · Auburn, CA
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 · 3
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 55
- Injuries
- Fatal
- Certificate
- Commercial
- Airplane ratings
- Single-engine land
- Instrument ratings
- Airplane
- Medical
- Class 2, With waivers/limitations
- Seat
- Left
- Toxicology
- Performed
- Flight hours
- 650 total
- Role
- Pilot-rated passenger
- Injuries
- Fatal
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Medical
- Class 3, With waivers/limitations
- Seat
- Rear
- Toxicology
- Performed
- Flight hours
- 1,532 total
- Role
- Pilot-rated passenger
- Age
- 30
- Injuries
- Serious
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Medical
- Class 2
- Seat
- Right
- Flight hours
- 250 total
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Calm
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 57 °F, dew point 50 °F
- Altimeter
- 30.19 inHg
- Observed at
- KAUN, 1 nm away
Docket · 13
The files NTSB released with the investigation on May 4, 2022, on NTSB’s docket system: statements, records, photos and specialists’ reports. 7.3 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.