Accident Overview
On September 23, 2019, at approximately 1754 Pacific daylight time, a Beech B35 airplane, registration N5277C, was substantially damaged in an accident near Portland, Oregon. The flight instructor and student pilot on board were seriously injured. The aircraft was operating under Title 14 Code of Federal Regulations Part 91 as an instructional flight.
Preflight and Fueling
The flight instructor reported that the airplane was serviced with 24 gallons of fuel before the flight, filled to capacity. The individual who refueled the airplane confirmed that fuel was added "to the bottom of the fuel caps." A mechanic who assisted in starting the airplane noted that it held short of the runway, running its engine for about 30 minutes prior to takeoff.
In-Flight Event
According to the instructor, while practicing maneuvers, the engine speed increased as if the propeller control had been moved fully forward. Shortly thereafter, the engine audibly slowed down drastically. The instructor cycled the propeller control and adjusted the throttle, but neither action had any effect. Consequently, the instructor executed a forced landing to a small field.
Post-Accident Examination
An FAA inspector examined the wreckage and found that the left-wing fuel tank was full, while the right-wing tank was empty. The fuel selector was positioned to the right fuel tank. After recovery, the inspector noted that the right fuel tank appeared intact. The fuel selector operated normally when each detent was selected.
Flight Data
Flight tracking data from a commercially available website indicated that the accident flight lasted approximately 1 hour and 19 minutes. According to the Beech B35 Pilot's Operating Handbook, each main fuel tank holds about 17 gallons of usable fuel.