Model Airplane News
FLIGHT MODES FOR GLIDERS
Glider pilots love flight modes because they allow us to configure the wing camber and elevator trim precisely for specific flying conditions. Picture a glider with flaps and ailerons on the wings.
You can have a flight mode that sets the elevator trim a bit up, the flaps a bit down, and the ailerons neutral and call that “launch mode.” Flip the switch to launch and your settings are optimized for a winch or high-start launch. At the end of the launch, flip the switch and maximize lift with thermal mode, in which the elevator is centered, the flaps are down a few degrees, and the ailerons are both down a few degrees, changing the camber of the entire wing. This maximizes the ability of the glider to fly slowly and find or work lift.
Let’s say that the lift is awful, and you need to speed out of the sink and off to another area of the sky to look for lift. Flip the switch into speed mode and the ailerons neutralize, the flaps reflex upwards a few degrees, and the elevator trims down a bit; the glider will scram to somewhere else where you can go back to thermal mode, slow down, and start your search for lift anew. When the inevitable happens and it’s time to land, select landing mode and the flaps extend, the ailerons reflex upward for crow mix or butterfly braking mode so you can precisely control your descent and nail that precision landing.
Motorized gliders make even better use of flight modes. Your launch mode has the throttle stick controlling throttle, the down-elevator trim usually required when a glider under power and any other settings you want to optimize.
Yet when you’re in landing mode, the throttle stick reverts to what most glider pilots use it for: adjusting landing spoilers, or the crow mix for precision landings.