Incident Summary
A multiengine airplane conducting single-engine training at 4,500 feet mean sea level experienced a sequence of failures resulting in a forced landing. The flight instructor had secured and feathered the left engine as part of the training exercise. After multiple unsuccessful restart attempts, the left engine remained inoperative.
Sequence of Events
Following the left engine failure, the right engine began to lose power, evidenced by a decrease in manifold pressure. The pilot reported difficulty maintaining the landing gear in the retracted position using the hydraulic system hand pump. As altitude was lost, the crew executed a forced landing to a field containing a gravel pit, with the landing gear partially extended.
Hydraulic System Information
According to the airplane's operator manual, the hydraulic system that powers landing gear extension is normally driven by the left engine. In the event of a hydraulic system failure, a hand pump provides an alternate means to extend the landing gear. However, in this incident, the hand pump was insufficient to keep the gear retracted or to fully extend it.
Investigation Findings
The investigation did not determine the reason for the loss of power in the right engine nor the cause of the insufficient hydraulic system pressure. No further factors were identified in the official source.