Event Description
The airplane impacted trees, terrain, and pedestrians after the pilot declared an emergency during takeoff from a nearby airport. Witnesses observed the airplane not climbing after takeoff. Air traffic controllers heard the pilot declare mayday three times. The pilot did not elaborate on the emergency situation. Witnesses observed the airplane turn left over the shoreline of a reservoir where it impacted a tree with its left wing. One witness stated the left propeller was not turning as fast as the right propeller and he heard the engines backfiring.
Examination Findings
Post-accident examination of the aircraft revealed no flight control anomalies. The left engine's top spark plugs were covered with black soot and the piston and cylinders were dark in appearance, indicative of an overly rich fuel/air mixture. The reason for the excessively rich mixture was not determined. The left engine was successfully test run twice following the accident, once utilizing the systems and plumbing in the airframe, and the second time in an instrumented test cell. Examination of the wreckage did find irregularities in the wiring circuits for both boost pumps and their associated cockpit switches; however, the relationship of these irregularities to the loss of power is uncertain.
Operational Context
Review of the airplane owner's manual revealed the emergency procedures for a loss of engine power after takeoff called for the retraction of the landing gear and the feathering of the propeller to obtain the maximum climb performance. The landing gear was not retracted and the left propeller was not feathered. Eighteen months prior to the accident, the pilot failed his first attempt to obtain his multiengine airplane rating due to improper emergency procedures during engine failure operations after liftoff. The pilot's total time in the same make and model as the accident airplane is unclear.