Friday, February 28, 2020

Loss of Engine Power (Partial): Vans RV-8, N470LM; accident occurred February 23, 2017 in Marysville, California

The National Transportation Safety Board did not travel to the scene of this accident. 

Additional Participating Entity:

Federal Aviation Administration / Flight Standards District Office; Sacramento, California

Aviation Accident Factual Report - National Transportation Safety Board: 

Investigation Docket - National Transportation Safety Board:

Location: Marysville, CA
Accident Number: WPR17LA067
Date & Time: 02/23/2017, 1730 PST
Registration: N470LM
Aircraft: GUARINO Vans
Aircraft Damage: Substantial
Defining Event: Loss of engine power (partial)
Injuries: 2 Minor
Flight Conducted Under: Part 91: General Aviation - Personal 

On February 23, 2017, about 1730 Pacific standard time, an amateur-built Guarino, Vans RV-8 airplane, N470LM, was substantially damaged during a forced landing in a field in Marysville, California. The airline transport pilot and passenger sustained minor injuries. The airplane was registered to and operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed, and no flight plan had been filed for the cross country flight. The flight originated from Half Moon Bay Airport, Half Moon Bay, California, about 1600 with a planned destination of Auburn, California.

The pilot stated that he departed with full fuel in the wing tanks earlier that day from an airport in Davis, California. He landed in Half Moon Bay for lunch and departed about 1600 with a planned destination of Auburn. As he approached the vicinity of Auburn, he decided to divert over to the Oroville Dam area to sightsee. He maneuvered around the area at about 2,000 ft above ground level (agl) and then started the leg back to Auburn. While en route, the engine experienced a loss of thrust and the pilot could feel the airspeed slow. The propeller was still windmilling, but the throttle had no effect on the engine. He noted that the propeller circuit breaker had popped out, but there were no other indications of an anomaly in the cockpit.

The pilot further stated that with the engine operating at partial power, he was unable to maintain level flight and configured for the best glide speed. He attempted to restart the engine twice and switched fuel tanks, to no avail. The pilot made a forced landing in a soft field, resulting in the airframe sustaining substantial damage. The pilot estimated that at the time of the accident he had enough fuel on board for about 1.5 hours of flight time.

A post accident examination and attempted engine operational test was completed. There was no apparent visible evidence of engine mechanical anomalies or thermal distress. Fuel continuity and pressure in the system was confirmed. There were several wires and a wiring harness disconnected in between the cockpit and the firewall; it is unknown if this happened after impact. A fuel source was rigged to the left fuel tank and investigators attempted to start the engine. The starter solenoid was heard to activate, but the engine would not start. An external source of power was used in attempt to start the engine and the engine cranked but would not start. A starting fluid was sprayed into the air intake, and investigators again attempted to run the engine; the engine temporarily started, but then quit after 1-3 seconds. The fragmentation of the electrical system precluded investigators from definitively determining the engine failure.

Pilot Information

Certificate: Airline Transport; Commercial; Military
Age: 27, Male
Airplane Rating(s): Multi-engine Land; Single-engine Land
Seat Occupied: Front
Other Aircraft Rating(s): None
Restraint Used:
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): Instrument Airplane
Toxicology Performed: No
Medical Certification: Class 1 Without Waivers/Limitations
Last FAA Medical Exam: 05/10/2016
Occupational Pilot: Yes
Last Flight Review or Equivalent:
Flight Time:   1379 hours (Total, all aircraft), 3835 hours (Total, this make and model), 500 hours (Pilot In Command, all aircraft), 150 hours (Last 90 days, all aircraft), 60 hours (Last 30 days, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: GUARINO
Registration: N470LM
Model/Series: Vans RV-8
Aircraft Category: Airplane
Year of Manufacture: 2008
Amateur Built: Yes
Airworthiness Certificate: Experimental
Serial Number: 80070
Landing Gear Type: Tailwheel
Seats: 2
Date/Type of Last Inspection: Condition
Certified Max Gross Wt.:
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time: 250 Hours at time of accident
Engine Manufacturer: Subaru
ELT: Installed, not activated
Engine Model/Series: H6
Registered Owner: On file
Rated Power: 190 hp
Operator: On file
Operating Certificate(s) Held: None 

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: KBAB, 113 ft msl
Distance from Accident Site: 14 Nautical Miles
Observation Time: 0058 UTC
Direction from Accident Site: 182°
Lowest Cloud Condition: Few / 4000 ft agl
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 3 knots /
Turbulence Type Forecast/Actual: None / None
Wind Direction: Variable
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 30.15 inches Hg
Temperature/Dew Point: 10°C / -2°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: HALF MOON BAY, CA (HAF)
Type of Flight Plan Filed: None
Destination: Auburn, CA (AUN)
Type of Clearance: VFR Flight Following
Departure Time: 1600 PST
Type of Airspace: 

Airport Information

Runway Surface Type: Dirt
Airport Elevation: 1539 ft
Runway Surface Condition: Soft; Vegetation
Runway Used: N/A
IFR Approach: None
Runway Length/Width:
VFR Approach/Landing: Forced Landing

Wreckage and Impact Information

Crew Injuries: 1 Minor
Aircraft Damage: Substantial
Passenger Injuries: 1 Minor
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 2 Minor
Latitude, Longitude: 39.369722, -121.423611 (est)


  1. Suburu auto conversion, I wonder how reliable these are. You don't hear about many builders using them anymore.

    1. The guy who did those conversions went belly up and has been trying it with Honda engines. The simplicity of traditional air cooled cylinders and direct drive is hard to beat, no matter how smitten the tuners are with high rpm water cooled engines.

      Even high dollar engine conversions can fail on simple parts that don't exist on traditional Lyc/Conti mills, such as a water pump pulley with failed socket head cap screws, for example: