Takeoff is the second most difficult thing to do in a glider. Landing is the first. Takeoff in a glider is difficult and more demanding then in a powered plane. The checklists and procedures should be carefully followed so one does not cause irreparable harm to one's self. Gliders take off in five ways. Each method has its own advantages and disadvantages.
- Aerotow- This is the standard takeoff method for most of the world. It involves towing a glider to altitude with a slow, powerful propeller driven plane. Cessna Ag Trucks, 180s, and Pawnees are popular as tow planes. The tow is described in depth more below.
Being towed by another airplane is a difficult, harrowing experience. You will be attached via a long (50m) tow rope to a Cessna 182 or Ag-Truck. You will signal to the pilot when you have completed your checklist. He will go to full throttle. He will begin his takeoff roll, you will rise and take off before the tow plane does. It is important NOT to gain altitude before the towplane takes off, as this would tip the towplane forward and the prop would end up as a giant weed whacker, killing the pilot. When in the air, it is important to stay directly behind the towplane and prevent slack from developing in the rope. When slack is taken out suddenly, the rope will break, as happened to me on my second flight. On tow, you should be slightly above the towplane, out of its propwash. Try to stay in view of the mirrors that the tow pilot has on his airplane. When towing, you will eventually want to release. You should pull the release handle and immediately bank to the left while the towplane banks right. (except in England, where you bank to the right, and thetowplane to the left. No joke). Tow is the most difficult part of glider flying, especially in turbulence. Techniques vary from pilot to pilot, and everyone has their own advice for towing. I shall not contribute to that mess. Concentrate, that is all that matters.
- Bungee Launch- This method is not used currently. Historically, it has been used in Germany, England, and in China by the Wong brothers. This is method is similar to a slingshot. The glider has a > shaped hook on the undercarriage that enables the bungee rope to easily disengage when flight velocities are reached.
Winch Launch- The winch launch has been in use since the 1920's when soaring as a sport really begin. Winches vary quite a bit. Converted auto and truck engines seem to be popular. There is one glider club in England that uses a Ford V-8 block converted to run propane. The cable triangle is attached to the bottom of a glider in a catch similar to the bungee launch hook.
Winch launching has a very interesting setup. A triangular metal plate is used. The glider is attached with a weak link (a link that breaks if a dangerous amount of force is applied to the glider during tow) to the top of the triangular plate. To the front of the plate is attached the primary winch cable. To the rear is attached the recovery cable. The recovery winch sits at the opposite side of the runway as the main winch; The end the glider starts from. The glider is set on the runway and attached to the triangle. The main winch is engaged and the glider takes off. When the cable forms about an 85 degree angle with the ground, it is released. At this point, the secondary winch is engaged and the main cable and triangle are dragged back to the ready position.
- Autotow- Gliders are attached by cable to an automatic transmission truck. An automatic transmission is used, unless the driver happens to be really good with a clutch. This is similar to a winch tow. The truck drives along the runway slowly accelerating to around 100 Km/h. The release procedures are the same as when winch launching. This type of launch is good when soaring from runways that are abandoned. Also, the truck can be used to pull the glider when it is trailered.
CB SIFT CBE This is the pre-takeoff final checklist/mnemonic for glider pilots. It should be closely followed. At this point, the plane is on the runway, ready to be attached to the launch device.
- Controls-the ailerons and rudder fully functional.
- Ballast-there is a proper amount of weight for stable flight and the center of gravity is within limits.
- Straps-you are strapped in. Your parachute is strapped on.
- Instruments-the altimeter is set for the correct
barometric reading, the airspeed indicator is working, and GPS, etc. is set. They are on and functional
- Flaps- The flaps are set for takeoff.
- Trim-the glider is trimmed for takeoff.
- Canopy-the canopy is closed and locked.
- Brakes(air and wheel)-the brakes are off.
- Emergency-you know where the out landing fields are and 180 degree emergency altitudes.
Sources:
- Personal knowledge
- http://www.chebucto.ns.ca/Recreation/BSC/winch.html
- Charlie Hayes, my glider instructor
- A couple of wonderful, wacky Brits
Back to the soaring node.