Accident Overview
A flight instructor and a student pilot were conducting takeoffs for pattern work in preparation for the student's first solo flight. Shortly after takeoff, during the initial climb, the instructor observed that the engine was running very rough and that the engine revolutions per minute (rpm) had decreased to about 1,700.
Sequence of Events
Declaring an emergency, the instructor announced his intention to circle back for landing. The control tower informed him that they were unable to clear him on the requested runway due to departing traffic. Immediately thereafter, the engine rpm dropped completely and the engine ceased operating. Continuing his turn toward the runway, the instructor determined that he would not be able to reach it and elected to set the aircraft down in the grass area between the runways.
Postaccident Examination
A postaccident examination of the engine revealed that the No. 4 cylinder exhaust valve had been ingested into the engine.