Fred Terzian forwarded pictures from an F1E activity, taken at Lost Hills.

F1E described (from FAI web site)

Gliding down the slope – human beings had dreamed about it for almost a million of years. Aeromodellers use the lift generated by the wind uphill for hundred years now, but model aircrafts with reliable magnet steering devices for a stable free flight had first been introduced by the German Hans Gremmer in 1951. These steering systems are simple, sturdy and since 1977 the heart of the FAI Free Flight class F1E. Like other free flight classes F1E is very much popular with competitions, but the training is exiting as well, satisfying the age-old desire.

In principle, a rudder is fixed above a strong magnet which turns freely on a hub in its center. Before the glider is to be launched downhill the rudder must be adjusted. It has to show in the flight path, with the magnet pointing to the north resp. south - as it is its nature. While gliding, the model aircraft will be disturbed by turbulences of the headwinds which even try to turn it back.