Diamond DA40 N292RA accident near Norfolk, Virginia

Probable cause

A partial loss of engine power due to the mechanic's failure to properly tighten the two clamps securing the flexible coupling from the intercooler to the induction inlet.

NTSB analysis

The pilot said that, shortly after takeoff, he heard a noise from under the engine cowling followed by a partial loss of engine power. The pilot was unable to maintain altitude and made a forced landing to a field, which resulted in substantial damage to the fuselage.

Data downloaded from the airplane's electronic engine control unit was consistent with an uncommanded decrease in induction air boost pressure on takeoff. Postaccident examination of the engine revealed that the flexible induction coupling between the intercooler and the engine induction inlet had backed off. The two clamps that secured the flexible coupling to the induction inlet were intact and safety wired. However, the two clamps were loose, and the induction tube could be inserted into the coupling without loosening the clamps. A review of maintenance records revealed that the flexible induction coupling and clamps had been removed and replaced at the last 100-hour inspection about 15 flight hours before the accident. Because the two clamps that secured the coupling from the intercooler to the induction inlet were recently replaced, it is likely that the mechanic who installed the clamps did not properly tighten them, and they loosened in flight, leading to the induction inlet backing off and resulting in a loss of engine power.

Text from the NTSB. Open the NTSB docket for ERA19LA272 for the full record.