jl@unc.UUCP (James Lipscomb) (02/27/85)
Do sailplane pilots use pitch to control speed and spoilers to control rate of descent (like throttle in power planes)? Yup. And here are some of the details. The main theme: the pilot has just one chance so it had better be quick and easy. Sailplane spoilers (or airbreaks, it makes little practical difference) are manually operated. Just pull the handle. No waiting for an electric motor to wind them out, and no power pilot worries about abrupt power changes or sudden cooling hurting engine. One pulls back on the handle to open the spoilers and descend faster, like pulling out on the throttle, but with the left hand on the spoilers and the right hand on the stick. In airplanes the hands have opposite jobs, so beware of "left hand for airspeed" when you fly sailplanes. Oh, and full spoilers may increase stall speed, the opposite of full flaps on airplanes. Watch out for that too. The spoilers can be popped out full all the way up to the redline on the sailplanes I've flown. No complicated "maximum flap extend speed." Too high? Throw in a full slip along with full spoilers. No restriction on that, unlike some power planes that restrict slips with full flaps, and you come down almost like a helicopter. Just do not land with full spoilers, unlike airplanes that can land with full flaps. Instead of toe breaks, sailplanes rig the wheel break to the spoiler handle, and forcing the handle against its back stop (full spoilers) activates the wheelbreak -- more wheel breaking with more force. Even if you are too fast on landing, you must back off the spoilers and wait to be planted firmly on the ground before hitting the wheelbreak. If you hit the pavement fast with the spoiler handle full back, the tire will screech and throw you three to six feet into the air. This repeats with little slowing from the wheel, just the opposite of what you wanted. The view out the front is spellbinding. I also saw a dragster do something like this when the parachute failed at the end of his run. He went into the dirt overrun. More usually one aims short of the intended touchdown point with half spoilers, then closes them at flare out, floating hundreds of feet in the considerable sailplane ground effect. When the touchdown point arrives, just pop the spoilers and you thunk to earth. Some sailplanes have flaps. I have flown the Blanik, which uses flaps just to reduce sink speed during thermaling. Spoilers only for landing.