Diamond Aircraft Ind Gmbh DA 40 NG N154BY accident near Goodyear, Arizona

Probable cause

Loss of engine power due to the installation of an improper air induction hose, which failed and prevented sufficient air intake to the turbocharger.

NTSB analysis

The student pilot had been signed off for a solo instructional flight. He performed the preflight check, including a check of the engine control unit (ECU), and noted no discrepancies. The run-up and initial takeoff were normal. However, during the takeoff climb out, the student pilot noted an engine power change followed by an ECU A and ECU B failure annunciation. The student pilot was able to land in an open field and impacted several drainage ditches, resulting in substantial damage to the right wing.

Inspection of the engine revealed that the hose that connects the air inlet to the turbocharger inlet was found to have de-laminated or collapsed. The loss of engine power was likely due to a partial vacuum in the turbo inlet and prevented the turbo from supplying the correct air inlet pressure to the engine, thus reducing power output.

The investigation found that a generic air induction hose had been installed on the accident airplane that was not part number specific. The Diamond illustrated parts breakdown calls for a specific part number for two flexible induction hoses. The operator reported that they inspected their fleet of airplanes and replaced the generic hoses with Diamond Aircraft Industries Inc. (DAI) hose.

Text from the NTSB. Open the NTSB docket for WPR17LA099 for the full record.