Four months ago, the waving of a white flag in auto racing conjured up the image of one lap to go. Now, it would seem to be a plea for the casualties to end.

Four months ago, drivers such as Mario Andretti could talk about a relatively accident-free decade in their sport. But, says Andretti, "When everything is quiet, I get really nervous."

With good reason.

In the past three months, there have been six major accidents and four deaths in auto racing. Two weeks ago, Jim Hickman, Indianapolis 500 rookie of the year, was killed in an accident in Wisconsin. This past weekend, Didier Pironi, the leading Formula 1 driver this year, was involved in an accident during practice for the German Grand Prix that left his career in doubt.

The two major questions are why now and what now. Everyone seems to have different answers.

Roger McCluskey, a veteran of 19 Indianapolis 500s, says, "The machine is now ahead of the man."

Andretti says there are "limits to human reaction."

Former driver Wally Dallenbach, now chief steward for Championship Auto Racing Teams (CART), says it's "a dangerous sport and it will never change."

Rick Mears, who finished second in this year's Indianapolis 500, says, "The odds are that accidents are going to happen. People expect high speeds now and you can't go back. They would lose interest."

Auto racing's flair for the dramatic cannot be denied. Anyone who saw Mears duel Gordon Johncock down Indianapolis' final stretch will attest to that.

But suddenly, it is a flair for the tragic that has put auto racing in the headlines. Most sports--save the major ones--set up promotions to attract attention; auto racing must now try to escape it.

Many in the sport say one way to do that is by limiting the speed at which a car enters a turn. Others say qualifying tires, used exclusively in Formula 1 racing, must be eliminated. Some say ground effect and qualifying and starting procedures have contributed to problems on the track. Each new accident brings new debate.

Nine years ago, Andretti qualified for the Indianapolis 500 at 195 mph. The day before, driver Art Pollard was killed in a qualifying attempt. Two weeks later driver Swede Savage was killed in the race.

At the time, Andretti said: "At 150 miles an hour, we had maybe seven seconds to react to something. Now we have eight-tenths of a second. It could be critical soon."

Mears qualified for Indy at more than 207 mph this year.

"Soon" may be now.

Gilles Villeneuve never liked qualifying tires, but because they give faster times, he used them. The tires are designed to excel over a couple of laps, but quickly wear away. "Two-lap wonders," Andretti calls them.

"Villeneuve said, 'That's going to kill somebody,' " said Pete Biro, an organizer of the Long Beach Grand Prix. "And he was right. We can't have guys running around on those tires."

No one can say whether Villeneuve would have tried to pass German driver Jochen Mass at full speed on May 8 in a qualifying run at the Belgian Grand Prix if he had been using regular tires. But riding on "two-lap wonders," Villeneuve could not wait. A third lap was coming up.

It was Villeneuve's last chance to improve his qualifying position, a crucial factor in Formula 1 racing, where not much passing is done. So he floored it. "He took a helluva chance," Andretti said.

The two cars' wheels locked. Villeneuve's car flew 150 yards through the air and disintegrated as it rammed the ground. Still strapped in his seat, Villeneuve was thrown 30 yards into a fence; he died at a nearby hospital the next day.

It was a horrific end to a brief but distinguished career.

For the sport, it was only the beginning.

One week later, Gordon Smiley became the 62nd person to die at Indianapolis Raceway--the first since Pollard and Savage in 1973--when, during a warm-up for a qualifying run, he overcorrected on a slight spin-out and crashed head-on into a concrete wall.

McCluskey blamed the accident on the speed at which the cars enter turns. Mears said the angle at which Smiley hit the wall nullified the question of speed--he would have had no chance at any speed. Andretti also mentioned the angle, but said if Smiley had gone into a full spin instead of trying to correct it, the consequences might have been less severe.

But they were all in agreement that it was a tragedy.

Just as they were all in agreement a month later, when Riccardo Paletti, driving in the Canadian Grand Prix in only his second Formula 1 start, drove into the rear of Pironi's stalled Ferrari and his car burst into flames. Paletti, 24, died later that day.

They were all in agreement when Mass drove into the crowd at the French Grand Prix, seriously injuring two spectators.

And again when Hickman's throttle stuck on the first turn of a practice run for the Tony Bettenhausen 200 and he crashed.

And finally when Pironi, driving in the rain in a practice run for the West German Grand Prix, apparently did not see the car in front of him, touched wheels and somersaulted three times in his Ferrari before hitting the ground.

"You can say that if Villeneuve didn't have qualifying tires, he wouldn't have had that pressure to pass," says Andretti, 1978 Formula 1 champion.

The International Auto Sports Federation, which governs Grand Prix/Formula 1 racing, has been meeting periodically this summer to consider changes that would make racing safer. So far, it is a case of many concerns, but no specific solutions.

In Indy racing, the problem doesn't exist. A driver must race on the same type of tires he qualifies on, and these tires wear much better than the qualifying tires used in Grand Prix racing.

Paletti's accident probably occurred because of the standing start rule of Grand Prix racing. He drove up from his back-of-the-pack starting position, unaware that Pironi, the pole-sitter, had stalled. No lights could warn him.

"It's a difficult start mechanically--for the drivers, the officials and for the machines," said George Couzins, who organizes Grand Prix events in this country.

"If a car stalls and an engine isn't working, a driver should be able to immediately put up his hands and a caution light should go on," said Biro.

Andretti acknowledges the problems in standing starts--"burned out clutches, nervous starters"--but points to the problems of the moving start at this year's Indy 500. Kevin Cogan, driving in front of Andretti, lost control of his car and forced Andretti out of the race before it began.

The problem of cornering speed, which McCluskey feels was partly responsible for Smiley's accident, is easier to recognize than to deal with.

"What we need to do is to reduce ground effect somewhat where we can slow the point of speed a driver enters a turn at," says McCluskey, competition director for the United States Auto Club (USAC).

"Coming into the corner is the point you begin to lose control. But then the trouble doesn't actually happen until the next straightaway. That's what happened with Smiley."

Dallenbach adamantly disagrees: "To limit corner speed is impossible . . . The only thing you can put limits on, which we do, is horsepower."

Mears says cornering speeds "might as well be kept at a limit. But there is no safety problem in the high speeds per se."

"If there was any common thing with these accidents we could take concrete action," says Couzins. "But they were all different."

"For sure, cars today are faster than yester- day's, but they're also safer," Andretti says. "You're never going to have a 100 percent safe race car. But we used to lose three, four, five drivers a year. It was an accepted situation."

Officials and drivers point to the absence of fires as one major safety improvement during the last decade. Protective cells guard the fuel tank so that most crashes will not turn into infernos.

On the stock car circuit, NASCAR has not experienced the plethora of accidents that Formula 1, USAC and CART have. The last death in a Grand National Division NASCAR race was that of Larry Smith at Talladega in 1973, according to a spokesman for the organization.

"We've taken great strides to make our cars safer," says Chip Williams, a spokesman for NASCAR. "We have an inner liner in the tire so no blowouts will result from a flat. Three thick metal bars surround the driver compartment, and we also have roll cages to prevent the driver from getting crushed in case he turns over."

"Accidents take place on the road every day, but you still drive," Andretti says.

Dallenbach says it is the same for a driver as for "a guy who gets knocked out in a ring, or the guy who walks on the moon. You're going to have close calls and injuries. That's the attitude you have to take."

Adopting an attitude is easy. Specific rule changes are harder to formulate.

"If you slow the cars down to 60, maybe there will be no accidents," Mears says. "But there has to be skill involved. The average person has gone 100 miles per hour, but 200, that's the magic number. Nobody can comprehend going that fast. That's the entertainment."

"We are supposed to be the best," Andretti says. "You can't always blame the accidents on outside elements. Our expertise should take over."

But until it does, the accidents will get the attention.