Science: Jet Jitney

In the race to build the world's smallest helicopter, the lead was claimed last week by Aeronautical Engineer Eugene Gluhareff, who put on display in Manhattan Beach, Calif, a jet-powered air jitney that straps on the back of the pilot like a parachute. Weight of the contraption: 68 lbs., and Gluhareff thinks he can eventually lower it to 45 lbs.

Tiny jet engines on the tips of the two rotor blades power the midget machine. The pilot-passenger carries twin tanks for the liquid propane fuel on his back, maneuvers by hand-held throttle and blade-pitch controls. One de luxe feature: pushbutton starting fired by three flashlight batteries. Gluhareff so far has tested his helicopter in tethered flight, estimates that when he tries free flight he will soar to 4,500 feet, buzz along at 50 m.p.h., have a cruising range of 25 miles, float lightly to earth if the engines conk out.

Gluhareff, 41, Russian-born son of Michael Gluhareff, engineering manager of Sikorsky's major helicopter program, plans to manufacture his device in partnership with Los Angeles Industrialist Robert McCulloch, hopes to get bids from the armed services and firms such as oil companies, which often need to plunk down a man in rugged terrain. Wistfully, Gluhareff rules out one potential customer: the earthbound commuter. Says he: "The CAA would never approve."