What happened
A sixty-six-year-old commercial pilot was operating an aircraft departing from McAlester Regional Airport in McAlester, Oklahoma. During the initial climb phase of flight, the pilot reported that fuel pressure began to fluctuate. This instability was quickly followed by a complete loss of engine power.
In an effort to restore engine function, the pilot activated the auxiliary fuel pumps and switched the fuel tank selection. Despite these corrective actions, the pilot was unable to restore adequate fuel pressure. With power unavailable, the pilot initiated a forced landing procedure in an open field nearby. The impact resulted in substantial damage to the aircraft structure.
The investigation
Post-accident examination of the aircraft revealed that it was approximately two and one-half months overdue for its required annual inspection. Additionally, records indicated that the pilot's medical certificate had expired, with the last valid issuance dated November 24, 1981.
During the technical investigation, a functional check of the fuel pump was conducted, which revealed no deficiencies in the pump mechanism itself. The engine was subsequently run to test operational integrity. The engine operated normally at 1000 RPM during this test. However, the engine run was terminated due to the discovery of a fuel leak originating at the mixture control shaft.
Findings
The investigation determined that the aircraft's maintenance status was not current. The expiration of the pilot's medical certificate also presented a regulatory compliance issue. The mechanical failure identified during the post-accident analysis pointed directly to the source of the power loss.