On August 19, 1994, at 1845 Pacific daylight time, a Piper PA38- 112, N2436N, collided with ground obstructions during a landing overrun at the Oakdale, California, airport. The aircraft was owned and operated by Diamond K Aviation of Oakdale and was on a local area instructional flight. The aircraft incurred substantial damage. The certificated airline transport pilot flight instructor and his dual primary student sustained serious injuries. The flight originated at the Oakdale airport about 1800 hours on the day of the accident as a local area flight. In a verbal statement to Federal Aviation Administration (FAA) inspectors, the student reported that the flight instructor intentionally entered the pattern for a downwind landing on runway 10 to simulate a power off forced landing downwind on the 3,000-foot-long runway. While on downwind, the instructor simulated the power loss by either pulling the mixture control to idle cut off or reducing the throttle. The student said the aircraft landed very long on the runway and the instructor added power to takeoff again when it became apparent that insufficient runway remained to stop on the ground. The aircraft ran off the departure end of the runway and collided with a canal ditch embankment. The winds were from 270 degrees at 10 gusting to 15 knots.