Piper PA-28-181 N428PA accident near Phoenix, Arizona

Probable cause

The flight instructor's failure to attain and maintain adequate airspeed while demonstrating a soft-field takeoff.

NTSB analysis

The flight instructor was demonstrating a soft-field takeoff to his student. During the takeoff roll, he applied full back pressure on the yoke, heard the stall horn, and lowered the nose. As the aircraft left the ground, the flight instructor heard the stall horn a second time. The airplane's right wing began to rise as the aircraft reached an estimated altitude of 20 feet above ground level. The flight instructor checked that the throttle was full forward, but the airplane would not accelerate. As the airplane continued to turn left it departed the left side of the runway and the left wing impacted a runway information sign. The airplane came to a stop in the grass off the left side of the runway. The left wing's forward spar was damaged and the left fuel tank was ruptured. The right wing's outer 4 feet (estimated) was bent up and the engine's firewall was wrinkled.

Text from the NTSB. Open the NTSB docket for WPR10CA172 for the full record.