Pilot Debrief

CESSNA 172F near Auburn Hills, MI — 2022-12-21

Final reportCEN23LA067
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Date
2022-12-21
Location
Auburn Hills, MI, USA
Aircraft
CESSNA 172F
Registration
N8768U
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Climb

Probable cause

The catastrophic engine failure due to lack of oil lubrication, which resulted from the pilot’s failure to follow the airplane and engine manufacturers’ guidance for cold weather operation.

NTSB narrative

The pilot reported that shortly after takeoff, as the airplane was climbing through about 3,000 feet, the engine “coughed and shuddered and started to run rough.” After unsuccessfully troubleshooting the engine, the pilot decided to conduct an emergency landing on a nearby road. During the landing the airplane’s left wing clipped trees, causing the airplane to veer left and flip over. The airplane sustained substantial damage that included damage to both wings, horizontal and vertical stabilizers, fuselage, and engine mounts. Postaccident examination revealed a trail of oil from the airplane’s hangar, down the taxiway, leading to the departure runway. The underside of the airplane was covered in engine oil, and the externally mounted engine oil cooler exhibited fresh oil leakage. The No. 4 cylinder connecting rod was separated and there were holes through the engine crankcase above the No. 4 cylinder, consistent with catastrophic failure due to a lack of lubrication. The outside air temperature at the time of the accident was about 28oF. According to the airplane manufacturer, engine oil with a viscosity of SAE 20 was to be used at temperatures below 40oF and SAE 40 was to be used for temperatures above 40oF. However, the oil in the airplane’s engine had a viscosity of SAE 50, with an operating temperature range of 60o to 80o F. Although the pilot added an oil additive to “thin the engine oil,” the aircraft manufacturer noted that the use of any oil additives during cold weather operation is not recommended. Additionally, the engine manufacturer indicated that operation of the engine without preheat could lead to oil congealing and engine failure, and operation of the engine above 1,700 rpm without first reaching minimum oil temperature could also lead to engine failure. The pilot reported that during the engine runup and takeoff roll the engine oil temperature gauge indication was “not registering,” and he did not remember whether the oil pressure gauge indication was in the normal operating range. It is likely that the pilot’s failure to preheat the engine before starting it, in combination with his failure to warm the engine to operating temperature before takeoff, resulted in the engine failure.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot did not preheat the engine before start in cold weather conditions.

NTSB coding

Evidence available

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

Docket documents7

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