What happened
During the takeoff and initial climb from a lake in a float-equipped airplane, the engine RPM began to decrease while the manifold pressure increased. The aircraft reached an altitude of approximately 400 feet AGL but was unable to maintain its climb. After emergency engine failure procedures failed to restore power, the pilot executed a sharp turn to avoid a building. The aircraft leveled off just before impacting the shore of the lake. There were no injuries reported in the accident.
The investigation
A post-accident examination of the aircraft and the engine revealed no mechanical malfunction. To further investigate the power loss, the engine was placed on an engine test stand, where it successfully attained its full rated RPM.