Incident Summary
The pilot was picking up the aircraft after it had been serviced. Approximately 20 minutes after takeoff, the engine quit. The pilot was forced to make an emergency landing in a field. During the landing sequence, the aircraft contacted some trees at the edge of the field and subsequently collided with the terrain.
Investigation Findings
Investigation revealed that during the servicing of the aircraft, a new fuel cap was installed. The new fuel cap was not vented, and the mechanic who installed it failed to find out if it needed to be vented. Service Bulletin #47 from the Champion Aircraft Corp., dated November 8, 1960, states that all Champion and Aeronca aircraft models 11AC, 11BC, 11CC, 7AC, 7BCM, 7CCM, 7DC, and 7EC must have vented fuel caps. It also states that if the caps are not vented, they must be vented prior to installation; otherwise, proper venting will not occur.