The clear plastic 80 foot tall balloon, which will supply the lift for a McLean woman and three men attempting the first nonstop balloon crossing of the United States, was still stuffed today in a wooden packing crate here.

Five balloon launching experts, who were supposed to be in this cheese making village on the Oregon coast for a Monday morning launching, are home playing with their children in Minnesota.

Even the helium truck has not showed up.

The weather is holding up the aeronautic show here -- the same problem that has vexed balloonists since a duck, a chicken and a goat made the first balloon flight near Paris in 1783.

The Da Vinci TransAmerican balloon needs what meterologists call a high pressure ridge, a fair weather pattern traveling east, upon which the balloon can ride like a surfboard on a wave.

But what Tillamook is offering all balloonists, until Thursday at least, is a pattern of dangerous weather, with rain and wind and gray mist hanging in the foothills of the nearby Coast Range Mountains.

Today and all last night the balloon's crew of four and a support staff of five prepared for the flight, which is scheduled to cover 2,295 miles in six days and nine hours to a landing near Norfolk, Va. They worked about a mile outside town in a cavernous wooden hangar, which was built by the Navy during World War II to house dirigibles that searched the Pacific for Japanese submarines.

The hangar, listed by the Guinness Book of World Records as the world's largest wooden structure, looks strikingly out of place among the Oregon cow pastures. Inside it, the crew was figuring out where in the gondola to store 8,000 pounds of scientific equipment and art materials that will be used to study and amuse the Americans over which the balloon will fly.

The equipment includes nine radios, 1,400 pounds of Oregon sand, lightshow equipment, devices for turning clouds blue and several thousand little balloons with a coupon inside entitling the finder to a free fir tree seedling.

"I found out [last night] that we had to move the stove. It was too easy to knock over a pan of boiling water." said Vera Simons, the McLean balloonist who conceived the transcontinental flight six years ago. She will pilot the balloon when a meteorologist in Bedford, Mass., gives a good weather forecast.

Meteorologist Bob Rice last year plotted the winds for the first successful transatlantic balloon crossing. In the history of ballooning there have been three flights longer than 2,000 miles. Rice has plotted the weather for all three.

Using computerized information gathered by the National Weather Service and his private weather forecasting company, Rice figures out the chances for a successful flight. He calls the crew of the Da Vinci several times a day to discuss the odds.

The final decision will be left to Rudolf J. Engleman, an environmental scientist from Boulder, Colo. who is the balloon's flight director. He will conduct air quality studies during the flight for the National Oceanic and Atmospheric Administration (NOAA).

Engleman said today he compares his decision on the flight to the decision facing a "young maiden of the past who must choose among several marriage proposals. 'how long does she wait? If she waits too long will there be any more proposals?"

Members of the balloon crew have said they are willing to wait until October for the best weather forecast.

If Engleman chooses wrongly, a thunderstorm can force the balloon to ground, ending the flight and scuttling the chance for a ballooning record. Nine aerospace corporations and the 7-Up soft drink company (which will advertise from the balloon) have put up more than $250,000, trusting that Engleman will choose correctly.

Engleman said today it has been hard to concentrate on the decision because of court proceedings in New York City, ABC television required his presence at a hearing on why ABC, instead of NBC, should be granted exclusive rights to broadcast the balloon flight.

"The court appearance [at which ABC was told by a federal judge to refile its suit in New York state court ] put us about three days behind schedule." said Engleman. "Even if we'd had the weather on Monday, we wouldn't have been ready."

All the crew members said today the ABC suit was something they did not need to hear about the week before the flight. Dr. Fred Hyde, the balloon radio expert and an eye surgeon in Prairie Village, Kan., said he heard about the suit just as he was about to perform a corneal transplant and that it did not help his concentration.

But in the four days until a possible weather break Thursday, the crew has plenty of time to prepare for the flight and discuss ballooning lore. The main attractions in this town of 4,300 people are tours of cheese factories and viewing the unswimmable cold Pacific.

One of the ballooning stories told today was of the balloonist, who in 1914 caused a stir in Portland, about 60 niles from here. The balloonist Jay Thompson, was accused in The Portland News of shameful activity aboard a balloon.

Under the headline "Girl Lured Into Balloon and Wronged High in Air," the story said Thompson frequently took "young girls" 2,000 feet in the air where they were "made the victim of balloon management."

Engleman said today if such a thing happened nowadays ?it wouldn't be such a serious crime." And Simons who will be flying with three men for more than a weel said she is "not worried."