CHALLENGER II N4017C accident near Clarion, Pennsylvania

Probable cause

The pilot's inadequate preflight planning, which resulted in a takeoff with the airplane's center of gravity aft of its limit and led the airplane to exceed its critical angle of attack and experience an aerodynamic stall during the initial climb. Contributing to the accident was the pilot's lack of flight experience in the aircraft make and model.

NTSB analysis

According to several eyewitnesses, including the current and previous owners, the pilot taxied out to the runway, returned to the hangar, and shut down the airplane's engine. The pilot reported to the previous owner that the red "water temp" indicator light illuminated. After discussing the need to open the cowling louvers, the pilot taxied to the end of the runway and began the takeoff roll. The airplane became airborne, immediately banked to the left, and then climbed to about 100 feet above ground level. The airplane continued into a 360-degree left turn and then nosed into the ground. The witnesses further reported that they heard the engine operating at or near full power until the airplane impacted the ground, with one describing the airplane as looking like a "lawn dart" until impact. Two other eyewitnesses reported that during taxi, the nose landing gear kept rising off the ground and that the pilot had difficulty maintaining ground contact with the nose landing gear.

Weight and balance calculations revealed that the airplane's center of gravity was aft of the aft-most limit of the envelope. The owner's manual stated that if the nose wheel will not remain in contact with the ground, ballast must be added until it does. The manual further stated that when the throttle is advanced, the nose will pitch down and when power is reduced, the nose will pitch up. While the airplane was equipped with a parachute system that was not armed by the pilot prior to flight, the low altitude at which the pilot lost control of the airplane would have made a successful deployment unlikely, even with the system armed. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The pilot reportedly had not flown the accident airplane make and model before; his lack of experience with the pusher-engine airplane's handling characteristics and the aft center of gravity resulted in a low-altitude aerodynamic stall.

Text from the NTSB. Open the NTSB docket for ERA14LA450 for the full record.