Gliders

If anyone can keep a glider, i.e., a motorless airplane, in the air for 20 hours, he can win a $3,000 prize and kudos; for ten hours, $2,000 and cheers. Such were the offers made last week by Edward S. Evans, Detroit manufacturer and founder of the National Glider Association.

Twenty hours would be a feat indeed. The present record is 15 1/2 hrs., made by a German. Germans have mounted 2,500 ft., have traveled 42 mi. in gliders. They have glider clubs at practically all universities. Each year the clubs hold a grand rodeo over the rolling hills of Wasser-kuppe, near Frankfort-am-Main. German flying organizations require that their pilots be graduates of flying schools. There is a Deutscher und Segelfluguerband and a special periodical, Flugsport.

The aerodynamics of gliding is that of motored flight. First airplanes lacked motors. Otto Lilienthal, air pioneer (anda German) was killed by his glider falling. But few others have had serious accidents.

For motive force gliders use air currents which swell over hilly terrain. Dune country, such as that near Chicago and off the Carolinas, is best for gliding. Knolls, ranges or terraces should slope toward the prevailing wind. One knoll should be 50 to 200 feet above all. And all should be bare of poles, trees, shrubs or other obstructions.

The glider is yanked into a 10 to 15 m. p. h. wind, which supplies lift. Thereafter it is the pilot's job to jockey his plane upon the air currents ascending over the rolling terrain. Air usually rises to twice the height of an obstruction. If the pilot can get above a cloud he has an easy time. Wind always rushes up over the edge of a cloud. And the up-moving air is what the glider pilot wants.

Several glider clubs exist in the U. S. Important ones are at San Francisco and the University of Michigan, Ann Arbor. The one at the University has been most active among the colleges.

Some attempt has been made to use gliders as load-bearing trailers to motored planes (TIME, March 11).

A complete glider costs $500 in the U. S. But its parts may be purchased for $100.

It is possible for a handy amateur to build a glider out of spruce or pine, wire, and fabric. Design is quite like that for a monoplane. (One popular German model amazingly resembles a Lockheed-Vega.) Wingspan may be up to 65 feet (span of a staunch commercial Ford trimotored transport). But 25 feet is more practical for beginners. The National Glider Association at Detroit will furnish blue prints. However best advice warns against amateur construction, or patching together of old motored plane parts.

At the Ail-American aircraft show in Detroit early in April, glider jockeys are scheduled to show their skill.