Cessna A188B N9224R

Summary

On 18 August 2006 at about 21:45 local time, a Cessna A188B registered N9224R was involved in an accident near Rolla, North Dakota, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

18 August 2006 at 21:45

Classification

Accident

Location

Rolla, North Dakota, United States

Coordinates

48.8844, -99.6208

Aircraft

Cessna A188B

Registration

N9224R

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Rolla → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CHI06LA240

Nobody was injured.

The pilot's failure to maintain clearance from terrain during the aerial-application flight, and the loss of engine power due to the overstress failure of the engine crankshaft sustained during ground impact. Contributing to the accident was the low-altitude at which the flight was being operated and the wheat crop the airplane encountered during the forced landing.

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

Read the full NTSB narrative

The aerial-application flight experienced a loss of engine power during a low-altitude turn while spraying a field. The pilot performed an immediate forced landing into a nearby wheat field. The airplane was damaged when it encountered the wheat crop, spun around, and impacted terrain. The on-site investigation revealed that the engine crankshaft had fractured and the propeller had separated from the engine. The propeller was never located and is believed to be in a nearby slough or a densely wooded area. The fracture of the crankshaft and the cracking of the oil slinger flange were the result of an extreme load on the front of the engine pushing aft and offset from the crankshaft centerline. Ground impact is the most likely source of the load. The offset load created bending loads on the crankshaft that led to an overstress fracture of the crankshaft. The aft loads pushed the crankshaft aft into the case, causing one side of the oil slinger flange to crack because it was restrained by the case. The location of the crankshaft fracture initiation was not diametrically opposite from the final fracture region, consistent with some amount of clockwise (as viewed from the aft) rotation during the fracture.

Quoted verbatim from the NTSB record.