Diamond DA40 N44HH accident near Yorktown Heights, New York

Probable cause

A fatigue failure of the turbocharger housing, which resulted in a partial loss of engine power.

NTSB analysis

The pilot intended to fly his airplane to an airport for an annual inspection. During the flight, while climbing to cruise altitude, the engine began to lose power. The pilot subsequently attempted a forced landing to a school field. During the forced landing, the airplane was in a steep right bank when the wingtip struck the ground, resulting in substantial damage to the empennage. The postaccident examination of the engine revealed that the diesel engine’s turbocharger induction housing was fractured in half and exhibited signs of an existing fracture surface. Further metallurgical examination revealed that the turbocharger housing separated consistent with fatigue cracking. The fatigue cracking emanated from the outer surface of the housing and proceeded circumferentially. Steps on the fracture surface indicated that fatigue cracking on multiple planes had coalesced into one main fatigue crack. The remainder of the fracture surface had macro features consistent with overstress. Based on this information, it is likely that failure of the turbocharger housing resulted in a reduced quantity of intake air being available to the engine and resulted in the partial loss of engine power described by the pilot.

Text from the NTSB. Open the NTSB docket for ERA23LA285 for the full record.