QUICKSILVER SPORT II N2812 accident near Newbury Park, California

Probable cause

The partial loss of engine power while maneuvering due to the blockage of the exhaust system by broken internal engine baffles that had shifted during the flight, which resulted in a forced landing and subsequent impact with terrain.

NTSB analysis

The pilot reported that, during the test flight, the engine began to run roughly. When the engine power did not increase, he chose to make a forced landing, which resulted in substantial damage to the airplane. A postaccident examination of the engine revealed that the exhaust system was in very poor condition, and previous weld repairs and several cracks were observed; maintenance records did not reveal when the weld repairs were made. Examination also revealed that the internal exhaust baffles were in very poor condition, and several broken baffles were observed, any of which could have shifted in flight. Therefore, the loss of engine power was likely caused by the blockage of the exhaust system by the broken engine baffles that had shifted from their original positions during the flight.

Text from the NTSB. Open the NTSB docket for WPR13LA318 for the full record.