Slope Flying with Compass Control (F1E)

Unlike free-flight models in other classes, slope-soaring models (FAI Class F1E) are equipped with a compass-controlled system. The system is at least 100 years old and consists of a “compass needle”—a strong magnetic rod that moves the rudder smoothly and effortlessly. The rudder is set to the desired flight direction, while the compass always points north. If the model deviates from the set direction during flight, the compass corrects the course. Instead of a mechanical compass, electronic devices can also be used to move the rudder via a small servo.

The hang glider model can not only maintain a straight course, but also fly circular or other patterns using an electronic or mechanical timer. The timers can also trigger the so-called thermal brake, which terminates the flight by raising the elevator. It is not possible to directly influence the model’s behavior during flight. Everything must be programmed before takeoff—including the addition of weights.

Once the pilot has released the model and can no longer influence it—neither its flight path, climb, nor descent—the pilot watches his or her model with bated breath. Will it stay in the air for the required (for example) four minutes, or will it land early? Flight times are set by the competition director. In a tiebreaker, these can last up to seven or eight minutes. Flight times depend, among other things, on the altitude of the launch site above the flat terrain, as well as on wind direction and wind speed. After takeoff, the pilot can only watch his aircraft and hope for the best. This is when it becomes clear whether all the settings and the timing of the launch were chosen optimally. If the model lands too early, he’ll try to fine-tune everything in his next flight and observe the weather conditions even more closely. It’s possible he was simply unlucky with the interplay of wind and sun. As a free-flight enthusiast, he learned that early on.

It’s not uncommon for the models to have to be retrieved from kilometers away. Landings in trees are almost a given. The Swiss team experienced this several times. The models have to be back in the air by the next launch window. That requires some physical fitness. The calm in the launch area is a welcome relief. The Swiss team appeared calm and focused—exemplary teamwork—in contrast to teams that forgot all about flying amid the commotion of their smartphones. Shortly before this, our free-flight pilots had achieved outstanding results at the European Championships in Romania. This time, they were unable to repeat that success. The World Championships are scheduled to take place at the same location in 2025. Let’s hope the organizer can step up and be able to host the event in a manner befitting a World Championship. For the Swiss free-flyers, the lack of suitable sites is a major challenge. They deserve our utmost respect.