Drewry Hutcheson was still in a daze in the crumpled cab of his truck on the Capital Beltway yesterday morning when he realized that the driver of the truck that had slammed into him was in even more trouble.

"The whole world had lit up from the bright flames," said Hutcheson, a 64-year-old trucker from Alexandria who squeezed himself out of his own truck to attempt a daring predawn rescue near Annandale.

"I went around to his truck and his body was lying partially out of the left side," Hutcheson said. "The fire was flaming all over the right side, but hadn't ignited his clothes yet.".

With the help of three other men, Hutcheson struggled successfully to free 30-year-old Kenneth Fleming of Goochland, Va. The crash had wedged Fleming's leg in the cab and flames were licking the truck cab as the men frantically sought to free him before rescue units arrived.

"When I got there, the whole cabin was on fire," Hutcheson said.

"He was screaming, he was moaning," said one of the rescuers, Julian Flores, 21, of Mount Vernon.

Hutcheson said he believed the situation was critical. "The man was dying, he was going to burn up."

With burned hands, Hutcheson clambered onto the top of the concrete barrier that divides the outer and inner loops of the beltway near Annandale. He managed to kick Fleming's left leg free of the seat. "I kicked as hard as I could and, luckily, it got free," said Hutcheson.

The rescue averted what police said could have been another fatality in the series of tractor-trailer accidents that have plagued the Beltway. In the first six months of 1984 alone, according to the American Automobile Association, there were 198 Beltway accidents involving tractor-trailers.

Fairfax police said yesterday's accident occurred about 5:20 a.m. when Fleming fell asleep at the wheel of a contract mail truck he was driving on the inner loop just east of Braddock Road in Fairfax County. His truck crashed into the rear of Hutcheson's 18-wheeler, which was loaded with four concrete storm pipes, according to police. Both rigs smashed into into the concrete barrier. "He Fleming went into the retaining wall and all I could see is that I had no other place to go," said Hutcheson. One of the concrete pipes spilled onto the roadway, but did not strike any vehicles. Fleming's truck burst into flames on impact, police said.

Hutcheson quickly wiggled through a window. "That's when I knew I was alive."

Flores said he was amazed to find one of the rescuers was the other driver. "I thought it was pretty much a superhuman effort. I would have been in shock if I were him," he said.

The accident left Fleming in serious but stable condition at Fairfax Hospital with second degree burns on the arms and cuts on the legs. Police closed three lanes of traffic, backing up morning rush hour for five miles. It took workers four hours to clear the debris.

Staff writer Joseph E. Bouchard contributed to this story.