Pilot Debrief

DIAMOND AIRCRAFT IND INC DA 40 near Kapolei, HI — 2023-12-04

Final reportANC24LA005
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Date
2023-12-04
Location
Kapolei, HI, USA
Airport
PHJR
Aircraft
DIAMOND AIRCRAFT IND INC DA 40
Registration
N691YW
Category
Airplane
Highest injury
Serious
Fatalities
0
Phase of flight
Initial climb

Probable cause

A partial loss of engine power due to lose baffling from the muffler, which resulted in an obstruction of the exhaust system.

NTSB narrative

While enroute the pilot moved the throttle control lever forward and heard a “pop” sound come from the engine, followed by a rumbling noise and an airplane vibration. The pilot pulled the throttle back to its original position in an attempt to stop the rumbling and vibrations and turned the airplane back toward the runway for an emergency landing. Engine power was not restored, and the airplane began to lose altitude, so the pilot performed a forced landing, which resulted in substantial damage to the fuselage and both wings. Postaccident examination revealed that baffling from the exhaust muffler had broken loose, blocking about 3/4 of the opening. The blocked exhaust reduced the volumetric efficiency of the engine cylinders, resulting in the partial loss of engine power.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have aborted the flight after hearing the initial 'pop' sound.

NTSB coding

Evidence available

  • Photos
  • 6 docket documents
View NTSB final reportView NTSB docket

Docket documents6

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