Accident Details
On the day of the accident, a dual-student and an instructor were conducting training flights at Ashland Airport. The training included hovering exercises, hovering autorotations, hovering loss of tail rotor effectiveness (LTE) maneuvers, and stuck-pedal exercises on a parallel taxiway. They also performed a series of run-on landings to runway 30.
Maneuvers and Landing
The final maneuver was a full-down autorotation to runway 30. The maneuver was initiated from an altitude of about 300 feet above ground level (agl), with the flare started at about 50 feet agl. According to both the student and the instructor, the flare and touchdown were performed correctly and were uneventful. The helicopter then slid directly down the runway for approximately 150 feet. Just prior to coming to a normal stop at about five knots, the left skid sank into some soft tar on the runway surface. The helicopter veered abruptly to the left and rolled over onto its right side.
Runway Surface Condition
After the accident, the occupants exited the helicopter and found that the tar in the area where the aircraft rolled over was thick, soft, and sticky. In a post-accident interview, both the student and the instructor stated that when they departed Medford for Ashland, they were not aware that the Ashland Airport runway surface was made of chip-seal, a combination of tar and crushed rock. The instructor reported that although the runway surface did not seem problematic during the run-on landings, he noticed when they came around the pattern for subsequent maneuvers that he could see imprints in the surface from previous skid contacts. He further noted that the temperature at the time of the accident was just over 90 degrees Fahrenheit, and on the previous two days the temperature had reached about 100 degrees Fahrenheit. He also stated that the runway surface was inconsistent, with some areas containing more rock and others more tar in the composite.