Incident Overview
An aircraft on a test flight following maintenance, which included adjustment of the absolute controller, experienced a loss of engine power during takeoff. The pilot had completed before takeoff checks, and everything appeared normal. At approximately 500 feet above ground level, the engine lost power.
Pilot Actions
The pilot turned on the boost pump, and the engine regained power briefly before quitting again. Subsequently, the pilot switched fuel tanks and checked the mixture, but the engine would not restart. A forced landing was executed on a public road with the landing gear and flaps extended. During the landing, the aircraft slid across the road and then parallel to a fence until it struck a fence post.
Investigation Findings
Examination and post-accident test runs of the engine revealed that the absolute controller was out of adjustment, which caused an over-rich mixture. The pilot's action of activating the boost pump after the initial engine failure aggravated the situation, leading to engine flooding.