Pilot Debrief

CESSNA 172S near Phoenix, AZ — 2018-06-26

Final reportWPR18LA181
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Date
2018-06-26
Location
Phoenix, AZ, USA
Airport
DVT
Aircraft
CESSNA 172S
Registration
N154ME
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Maneuvering

Probable cause

A total loss of engine power due to crankshaft failure as the result of a subsurface fatigue crack.

NTSB narrative

While maneuvering during a local instructional flight, the engine began running rough, and the instructor decided to return to the airport. The engine subsequently lost total power and the propeller stopped rotating. The instructor performed a forced landing to a clearing where the airplane nosed over, resulting in substantial damage. Examination of the engine revealed that the crankshaft was fractured at the No. 4 connecting rod journal. The fracture surface was flat and crack arrest lines were consistent with a fatigue fracture which initiated subsurface. No flaws or embedded particles were observed at the site of the fatigue initiation. The engine was overhauled about 3 years before the accident and had accumulated 2,798 hours of operation since the overhaul.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot should have declared an emergency upon experiencing engine roughness.

NTSB coding

Evidence available

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

Docket documents6

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