Cessna 172F N8768U

Summary

On 21 December 2022 at about 14:47 local time, a Cessna 172F registered N8768U was involved in an accident near Auburn Hills, Michigan, United States. One person was on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

21 December 2022 at 14:47

Classification

Accident

Location

Auburn Hills, Michigan, United States

Coordinates

42.6711, -83.2205

Aircraft

Cessna 172F

Registration

N8768U

Category

Airplane

Year built

1965

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Troy → Troy

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN23LA067

1 person had minor injuries.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full 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.

Quoted verbatim from the NTSB record.