Pilot Debrief

MOONEY M20E near Stillwater, OK — 2022-06-18

Final reportCEN22LA255
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Date
2022-06-18
Location
Stillwater, OK, USA
Aircraft
MOONEY M20E
Registration
N5895Q
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Cruise

Probable cause

The inadequate maintenance and inspection of the engine induction air coupling, which impeded airflow to the engine and resulted in the subsequent partial loss of engine power.

NTSB narrative

The pilot reported that, during cruise flight, the engine lost partial power, which necessitated an emergency landing on a highway. During the landing, the airplane impacted a road barrier, which resulted in substantial damage to the left wing. During a postaccident examination, the induction air coupling was found wrapped in gray tape. When the tape was removed, separations were visible on the top and bottom at the flange on the inboard side. The top and bottom separations likely reduced the rigidity of the coupling when the engine was operating. Examination of the inside of the coupling showed that the lower portion appeared to be permanently deformed in a manner similar to compression. Therefore, because of the reduction in the coupling’s rigidity, the coupling had likely closed due to suction from the engine, which impeded airflow. Tape should not have been applied as a fix for the induction coupling separations. The investigation could not determine when the coupling separations appeared or the tape was applied, but those events had likely caused the permanent deformation to the coupling. The airframe and powerplant mechanic, who performed annual inspections for the airplane during the 3 years before the accident. should not have allowed the airplane to return to service with the tape applied and the coupling deformed.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have checked engine performance before departure.

NTSB coding

Evidence available

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

Docket documents8

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