Incident Overview
A Piper PA-12 aircraft experienced a loss of power shortly after takeoff, prompting the pilot to execute an off-airport landing. During the landing, the aircraft impacted a corn field.
Investigation Findings
Examination of the aircraft following the incident did not disclose any malfunctions or mechanical failures. The aircraft was operating on auto fuel at the time of the accident.
Relevant Study
An FAA study predicts that vapor lock is most apt to occur in a hot engine, under high fuel flows, low cooling air flow, and when the Reid vapor pressure is higher than 7 psi. Auto fuel in winter is typically 15 psi.
Conclusion
The cause of the power loss was not determined from the examination, and no probable cause is stated in the source.