Air Tractor Inc AT-802 N445HA accident near Herington, Kansas

Probable cause

The design of the spray valve control lever, which restricted the range of the left rear rudder and brake pedal and resulted in a loss of control during landing.

NTSB analysis

The flight instructor in the rear seat reported that during the landing roll the tailwheel unlocked, and the airplane turned right. He applied full left rudder and attempted to apply left brake, but when the left rudder and left brake were both applied, the top of the pedal toe brake contacted the spray control lever pushrod, preventing full braking. The airplane continued off the right side of the runway, where the airplane impacted a ditch and sustained substantial damage to the wings.

Postaccident examination revealed that the front-seat rudder/brake pedals were found to move to their full range of motion without interference. The rear-seat rudder/brake pedals were found in the forward adjustment position. With full left rudder deflection, the left brake pedal’s range was restricted by the upper spray valve control pushrod. There were no other mechanical malfunctions or failures with the airplane that would have precluded normal operation.

The design of the spray valve control lever and left rear rudder pedal in the forward adjustment position restricted the left rudder and brake pedal, which resulted in a loss of control during landing.

Text from the NTSB. Open the NTSB docket for CEN23LA425 for the full record.