An intense localized rainstorm with violent, rapidly shifting winds surrounded Moisant Airport about the time Pan American Flight 759 crashed and killed 153 people, a pilot and a woman driving near the airport testified today.

Nonetheless, one airline captain, who experienced extreme difficulty on his own takeoff moments before the July 9 Pan Am flight, said he saw no reason, based on the information available, to have delayed takeoff. Two other pilots who also flew about the same time agreed.

Two pilots said they chose runways other than the one used by the Pan Am flight because of rainstorms to the east of the airport, where the Pan Am Boeing 727 crashed. A third -- who said he was fully prepared to take off immediately behind the Pan Am flight -- said he probably would have used another runway if the air traffic controllers had not suggested that it was "noise sensitive." All the pilots said weather was normal for New Orleans at that time of year and that it was weather they had flown in many times before.

The testimony came in the first day of the National Transportation Safety Board's public hearing into the Pan Am crash, the nation's second worst. Witnesses tended to corroborate the prevailing theory that a strong, sudden shift in wind velocity and direction -- wind shear -- may have caused the accident.

The most significant report of dangerous winds "on the runway" was transmitted by the copilot of Republic Airlines Flight 632, which preceded the Pan Am flight by seven minutes and used a runway that intersects the one Pan Am used. Republic's transmission went to one air traffic controller, but was not shared with the controller in radio contact with Flight 759.

The captain of that Republic flight, Thomas C. Owens, testified that he suddenly and unexpectedly encountered intense, heavy rain while he was speeding down the runway to gain takeoff speed.

"It was hard to ascertain where the center line of the runway was," Owens said, so he jerked his plane into the air before it reached full takeoff speed, a procedure he conceded was "uncommon." This set off a warning system on the plane that advises the pilot of insufficient air speed to fly. The plane was able to recover, apparently because it suddenly encountered a strong head wind, which enhances flying ability.

Kristeen K. Anglia, who was driving along a street close to the end of the runway used by Pan Am 759, said she drove into a rainstorm that looked like a "wall of water." Wind began buffeting her car.

She looked up and saw the Pan Am plane. "Whole trees were swaying," she said. The wind she described would have been a tailwind--the opposite of what a pilot wants on takeoff.

Robert C. Ferguson, a U.S. Air captain who was scheduled to take off immediately behind the Pan Am flight, worried about the weather, but elected to use the same runway. "I remarked to my copilot, 'We'll see how Pan Am does and then we'll take a look.' "