Sequence of Events
A student pilot completed three full-stop landings alone before the instructor boarded the aircraft. After the instructor boarded, another full-stop landing was made. During the landing roll, the instructor noticed that the last half of the grass runway was wetter than the first half. The instructor then decided to take off and land in the opposite direction, to the east.
On the first landing to the east, full flaps were used and the approach speed was 80 knots. The aircraft touched down halfway down the runway. About 1,700 feet of runway remained when the brakes were applied. According to the instructor, the aircraft slowed down in a normal manner until soon afterwards the student stated he had lost brakes.
The instructor attempted to ground loop the aircraft. However, when he tried, the aircraft skidded instead of turning and went off the runway into a ravine and nosed over.
Aircraft Examination
Examination of the aircraft revealed that the brakes were inoperative.