At least a half-dozen groups in five countries are seriously engaged in the quest to show that man can fly through the air and land without a parachute, according to a December New York Times report. "All of this is technically possible," said a physics professor, referring to the wing suits fliers are testing. "The thing I'm not sure of is ... safety." Some wing suits have slowed vertical descent, briefly, to about 30 miles an hour, though the fliers were still moving horizontally at about 75 mph, which is why all testing is done with parachute backup. American Jeb Corliss believes he could land, even at 120 mph, provided that his neck were protected by a sturdy-enough frame on the wing suit.