Cessna 150F N7818F accident near Sully, Iowa

Probable cause

The pilot's failure to attain an adequate climb rate during the initial takeoff, resulting in the airplane settling back down and departing the runway. Contributing to the accident was the pilot's inadequate preflight planning and preparation.

NTSB analysis

The pilot and his passenger were taking off on a 2,130-foot turf runway. During the takeoff, the airplane lifted off, remained in ground effect, veered to the left, and then settled back onto the runway where it subsequently impacted a sign and a tree. Postaccident examination of the engine revealed that two of the No. 4 cylinder's three piston compression rings had fractured but remained intact. Since two rings were intact and the third ring was not fractured, compression in the cylinder should not have been substantially reduced. Postaccident computations of ground roll distance showed that the acceleration achieved during the accident takeoff roll was almost equal to that of the airplane's expected performance on hard-surface runways, indicating that there was not a substantial decrease in available propulsive thrust at the time of takeoff. Federal Aviation Administration guidance recommends that pilots ensure that runway length is equal to the aircraft manufacturer's published takeoff or landing distance plus an 80 percent safety margin for takeoffs on a hard surface and double the manual distance for takeoffs on sod.

Text from the NTSB. Open the NTSB docket for CEN11LA366 for the full record.