Edition: U.S. / Global


Published: July 3, 1987

Two adventurers lifted off today and headed out over the sea on a 3,400-mile trans-Atlantic flight in a huge hot-air balloon, a journey no one has completed.

A little more than 10 hours into their flight, the balloonists had covered 1,000 miles to break a distance record and were speeding along at up to 142 miles an hour in temperatures 40 degrees below zero Fahrenheit.

Traveling far faster than expected, Richard Branson. a wealthy British businessman, and Per Lindstrand, a Swedish balloonist, broke the distance mark for hot-air balloons at 907 miles while passing about 140 miles southeast of St. John's, Newfoundland, at 27,900 feet.

''It has been the most spectacular and magnificent flight,'' Mr. Branson said by radio. ''When we arrived at 27,000 feet we hit the very cold weather. There was an enormous cloud behind us that created a massive vapor trail. For a moment I thought the balloon was on fire.''

At 7:30 P.M., the balloon approached the halfway mark, averaging about 100 m.p.h.

If the balloonists maintain their early speed, they would reach their destination, Great Britain, in about 40 hours, said Jim Mitchell, a spokesman for the flight. But the balloonists are prepared to stay aloft more than three days, expecting to land Saturday night. 'A Lot of Things Can Happen'

''You never feel comfortable,'' Mr. Mitchell said. ''You're always relying on the wind and they're only about one-quarter or one-third of the way. A lot of things can happen in between.''

As 200 people watched, Mr. Branson, 36 years old, the head of an entertainment conglomerate and the chairman of Virgin Atlantic Airways, and Mr. Lindstrand, 38, the balloon's designer, who now lives in Britain, took off in the black Virgin Atlantic Flyer at 4:10 A.M. from the base of Sugar Loaf Mountain in western Maine.

''This is a magnificent moment in my life,'' Mr. Branson said as he and Mr. Lindstrand prepared to climb into a pressurized capsule hanging from the balloon. ''I haven't had time to be scared. I want to enjoy every minute of this.''

The balloon, as high as a 21-story building and said to be the largest ever built, ascended quickly and was out of sight in minutes, heading east toward the coast about 100 miles away.

The longest previous flight by a hot-air balloon was 907 miles, entirely over land. Harold Warner made that trip in 27 hours and 23 minutes. #2 Propane Fuel Tanks Lost Two of the balloon's 12 propane fuel tanks, snagged by a ground line, were knocked off as the craft ascended, but another flight spokesman, Crispin Williams, said the balloon would probably have enough fuel to make it to England. He said the balloonists would probably have to fly higher to pick up faster winds to make up for the lost fuel.

Mr. Branson's father, Ted, and his mother, Eve, watched the takeoff, along with residents, reporters and safety officials.

Both parents said they would like to have been with their son on the balloon. ''I can't imagine him not being adventurous,'' his mother said. ''He's always been a bit mad.''

The trip had been postponed three times in June because of weather.

The balloon and cabin, which cost an estimated $500,000, is making its first flight because the balloon is designed to self-destruct upon landing. Only smaller prototypes have been tested.

Only a helium balloon, the Double Eagle II, with a three-man crew led by Max Anderson in 1978, has flown across the Atlantic. That flight covered 3,108 miles in 137 hours.

Photo of the Virgin Atlantic Flyer lifting off (AP); Photo of balloon crew, Richard Branson and Per Lindstrand