Accident Narrative
On August 1, 2012, at approximately 2345 central daylight time, a Piper PA44-180, registration N586ND, operated by the University of North Dakota, veered off runway 17R after landing at Grand Forks International Airport (GFK), Grand Forks, North Dakota. The aircraft sustained substantial damage. Both occupants, a certified flight instructor and a student pilot, were uninjured. Night visual meteorological conditions prevailed, and no flight plan was filed. The local instructional flight was conducted under 14 CFR Part 91 and had originated from GFK at 2150.
The flight was a night local training mission. After several successful landings and takeoffs in the traffic pattern, the crew proceeded to their practice area for planned in-flight training. Upon return, with the student at the controls, the crew entered a right downwind for runway 17R for a full stop landing. The wind was light on the surface but stronger from the west at pattern altitude. Landing gear was confirmed down and locked verbally by both pilots. During the turn to final, a slight overshoot occurred due to the west wind at altitude, but the crew became established on final and stabilized. The final approach and touchdown were uneventful, though the touchdown point was long and the airspeed was fast. The flight instructor had planned to exit the runway at the Bravo exit but, due to the extra speed, elected to continue to the next exit. The student initially applied brakes evenly for an exit at Bravo, but the instructor instructed him to continue to the next exit and release the brakes to avoid stopping on the active runway. As the student released the brakes, the aircraft began to yaw abruptly to the right. The student stated he was not applying right brake pressure, and the instructor was not on the brakes. Both pilots added left rudder and left brake pressure in an attempt to maintain directional control but reported insufficient control authority to keep the aircraft on the runway. The aircraft continued to the right and turned into the grass, where the left main gear collapsed. Both throttles were at idle, and the gear had been confirmed down and locked just prior to landing. After the aircraft came to a stop, the crew exited uninjured. Structural damage was incurred to the left wing and fuselage behind the cabin bulkhead.
Aircraft Examination
Examination of the airplane’s flight controls, landing gear system, and brake system revealed no evidence of mechanical malfunction or preaccident abnormalities. A review of maintenance activity on the airplane showed two work orders related to the brake system. On November 28, 2011, both brake discs and linings were replaced. On December 13, 2011, the airplane was inspected for a reported right brake sticking intermittently during takeoff roll and taxi. After the accident, the operator’s maintenance personnel performed a thorough inspection but were unable to identify a problem. They inspected the right brake system, which included removal and disassembly of the pilot’s right master cylinder and brake hoses and inspection of the right wheel cylinder piston and linings for possible binding. No indication of blockage was found within the master cylinder or connecting hoses, and no scoring of the shaft was evident. The brake disc was true and showed no indication of overheating, and the linings were even with no indication of binding on the pins. The piston moved smoothly with no indication of binding. The copilot’s right master cylinder was not removed for inspection because it had been replaced due to leaking seals since the previous reported occurrence of brake drag on December 13, 2011.
The student and instructor did not state that there was any crosswind while landing.