Amateur-built RV8 N184DC accident near Guthrie, Oklahoma

Probable cause

A loss of engine power due to the separation and ingestion of an air filter retaining bracket into the engine cylinder.

NTSB analysis

The pilot reported that about 40 ft above ground level (agl) during the initial climb from the grass airstrip, engine cylinder Nos. 2 and 3 lost power. About 10 seconds later, engine cylinder Nos. 1 and 4 lost power. The pilot was unable to maintain altitude. He switched fuel tanks in an attempt to regain engine power but noted no change in the engine performance. The airplane impacted trees beyond the departure end of the runway and sustained substantial damage to both wings, fuselage, and empennage.

Postaccident examination of the engine revealed an air filter retaining bracket that was fastened to a fiberglass air snorkel/box had separated and was ingested into the No. 2 cylinder. The separated bracket then jammed the intake valve into the open position, resulting in a loss of engine power. Elongation was noted on the fiberglass where the rivets secured the fabricated retaining bracket.

Text from the NTSB. Open the NTSB docket for CEN24LA317 for the full record.