DA40 Diamond Star
Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument
Flight Crew Last 90 Days 60; Flight Crew Total 640; Flight Crew Type 640
Confusion; Distraction; Workload
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Object; Ground Excursion Runway; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Object
Aircraft Aircraft Damaged; Flight Crew Became Reoriented; Flight Crew Took Evasive Action; General Maintenance Action
Human Factors
During a training flight with a student; stopped for a break at a nearby airport. After taxiing back for departure; completed takeoff checks per checklist. Student was in control of aircraft; but I followed on the controls. Began normal takeoff roll on Runway 32. All instruments looked normal; airspeed was around 35-40 knots. The plane had a momentary pulse of the brakes and I thought student tapped the brakes. I told the student to put his heels on the floor. He said OK and I saw him move his feet further on the floor. Plane continued straight for a few seconds. Then the plane suddenly veered left. I took control and tried applying right rudder; then throttled back to idle and applied brakes. The airplane did not turn back to the centerline and did not slow down. I think the student stopped trying to control the airplane and removed his feet/hands from the controls. We hit a runway light and continued into the grass. We finally came to a stop about 150 feet into the grass. Neither of use was at all injured. We secured the aircraft and exited it. The nose pant was cracked; the back of the propeller was scratched; and there was a small dent in the left wing.
The reporter stated that to date (two months later) no mechanical cause for the runway excursion could be found. Both the brakes and steering were found fully functional during post flight maintenance examination. The reporter still believes that her student unconsciously applied left brake pressure. She could not see his feet from the right seat and makes her judgment based on the Mechanic's report and her experience at the time of this event.
A DA-40 student unconsciously applied left brake so the instructor rejected the takeoff but could not regain control and during the runway excursion the propeller and nose wheel pant were damaged along with a wing dent.