In stark contrast to his distinguished Boston Brahmin forebears, Timothy Saltonstall may truly be said to be a young man with both feet planted firmly in midair. Grandson of that pillar of New England rectitude, former Republican Sen. Leverett Saltonstall, Tim is a 34-year-old whose idea of a good time is to jump out of an airplane, tumble acrobatically down for a couple of thousand feet, and float onto a four-foot orange disk. As a career parachutist, Tim says, "I like being outdoors and I love air sports. That's all I'm really interested in."

It took him a while to convince the family patriarch that he was more than just an airborne drifter. "My grandfather was shocked when he learned what I was doing," Tim recalls. "But when he realized it was an international competitive event and saw me on Wide World of Sports a couple of times, he began to see there was something to it other than a freak risking life and limb."

Tim first caught the fever one day in 1961 near the University of Colorado. "I saw a couple of parachutes in the sky," he recalls, "drove to where they landed, and I've been involved ever since." His enrollment at Boulder broke the family's ancient Harvard connection, but his competitiveness was very much in the Saltonstall tradition. The senator, in fact, had been a hockey player and had led the Harvard crew to victory at Henley before World War I.

The eldest of four children, Tim plunged into athletics at a tender age. "We started skiing as tots," he remembers. "And we rode a lot. We always had horses." Summers were spent at his grandfather's seaside home in Maine, where Tim learned to sail everything from small boats to the senator's 60-foot sloop.

Tim's father, the late Leverett Saltonstall Jr., settled his family in farming country outside Ithaca, N.Y. But agriculture was not Tim's calling. Neither was school. He dropped out of college in 1962 and spent six months in his grandfather's Washington office. "I did anything that had to be done," he says, "errand boy, tours of the Capitol, chauffeur." Afterward he gave Boulder another year, quit for good and took up parachuting in earnest, winning the style event and finishing second overall in the 1965 national championships. Two years later Tim was drafted and shipped off to para-troop school at Fort Benning, Ga. "They sent me to Vietnam in the infantry," he observes. "I never jumped there."

Returning to civilian life in 1969, Tim and another wealthy expatriate from the East, James F. Curtis III, later leased a small airfield and lodge in California's Pope Valley, 90 miles from San Francisco. For the past three and a half years they have put a parade of chutists through some 75,000 jumps. There has been only one fatality, and that was a suicide.

Though the operation grossed $350,000 last year, Saltonstall still thinks of jumping more as fun than business. "It's like gymnastics," he enthuses. "You dive for 15 seconds to pick up as much velocity as possible, turn 360° right and left, then do a back loop and repeat it all again. If you are good, that should take only six seconds." In 15 years' defiance of gravity, Tim has made 2,800 jumps and logged nearly 6,000 pilot hours. He is also a skilled mechanic and chute rigger. "I am," he announces airily, "one of the few people in this business who can do it all."