On October 7, 2015, about 1130 Pacific daylight time, a Silvaire Luscombe 8F, N9918C, veered off the runway surface during the landing roll at Georgetown Airport (E36), Georgetown, California. The pilot, who was the registered owner of the airplane, and the flight instructor sustained serious injuries; the tailwheel equipped airplane sustained substantial damage. The flight was conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as a local flight. Visual meteorological conditions prevailed at the time of the accident, and no flight plan had been filed. The flight originated from E36 about 1115. In a written report, the pilot stated that he had conducted two flights that day in the tailwheel equipped airplane; the first flight where he was the sole occupant of the airplane, and the second flight with the flight instructor for the purpose of conducting a biennial flight review. During the second flight, the pilot assumed a role of the pilot-in-command, as the flight instructor's medical certificate was not current. However, the 14 CFR 61.23(b)(5) states that "A person is not required to hold a medical certificate when exercising the privileges of flight instructor certificate if the person is not acting as pilot-in-command or serving as required pilot flight crewmember." The airplane was equipped with a bench seat that was adjusted for the pilot's height; therefore the flight instructor, who was shorter than the pilot, was unable to reach the rudder pedals. Prior to the flight, the pilot offered to acquire a cushion for the flight instructor, but the flight instructor declined. The pilot stated that the departure and local area flight had been uneventful, and that the three-point landing on runway 34 was normal. However, a few seconds later the airplane bounced slightly but did not require any rudder pedal input. Shortly thereafter, the airplane veered 30 degrees to the right. The pilot applied full power as the airplane exited the right side of the runway and impacted the ground on a downhill slope adjacent to the runway. The airplane sustained substantial damage to both wings and the fuselage. The pilot reported no abnormalities with the aircraft prior to the accident that would have precluded normal operation of the airplane.