Gerald E. Smallwood still has the first plane he ever flew--a tiny toy model he piloted around the house at the age of 4.

Today, the 53-year-old Smallwood is hoping to do a lot more flying, thanks to the Supreme Court. The court let stand this week a ruling that United Air Lines had subjected Smallwood to age discrimination when it refused to hire him as a pilot because he exceeded the company's age limit for pilot trainees.

"When I heard about it the court decision , my brain went relatively numb," said Smallwood, a Fairfax County lawyer who is hoping that the decision will bring him up to $400,000 in back pay and damages, along with a return to the cockpit. "It was probably not until five or six hours later that the excitement really hit."

Aviation and legal experts said the court's action in the Smallwood case won't affect most pilot applicants because the recession-plagued industry has hired few pilots in recent years. Instead, it marks a personal victory for a stubborn Air Force veteran who was willing to battle for almost five years to get back in the cockpit.

Smallwood was furloughed when Overseas National Airline stopped operating in the mid-1970s, and was determined to find another pilot's job. "I always said what I wanted to be was a pilot," said Smallwood. "I can't explain it. It's exciting. I guess you could call it an obsession."

Although Smallwood hopes the decision will force United to hire him, a spokesman for United said yesterday that the corporation had not yet decided what to do.

"We're going to review the whole matter," said Joseph P. Hopkins, adding that the case has been remanded to U.S. District Court in Alexandria for further hearings on Smallwood's demands for a job, back pay and monetary damages. "We don't have to be hasty in making decisions on this."

Smallwood's crusade began when he filed an job application with United in 1977 after 10 years with Overseas. United informed Smallwood by letter that he possessed "fine qualifications," but that the airline had a policy of considering applications only from people between the ages of 21 and 35.

"I didn't want to get back at anybody or prove anything," said Smallwood, who spent almost a thousand hours working on the case with his attorney, Wyatt Durette, and taught school part time to finance his endeavor. "I just wanted to fly for United."

United argued in court that the hiring policy minimizes pilot training expenses and promotes maximum safety to its passengers. "It all has to do with the investment that goes into training a pilot," said Hopkins. "If you train a person at a younger age, you recoup that investment at a younger age."

U.S. District Judge Albert Bryan of Alexandria ruled in United's favor, but the 4th U.S. Circuit Court of Appeals in Richmond reversed that decision, concluding that the safety argument and "economic considerations" do not justify age bias. The Supreme Court's decision allows the 4th Circuit's ruling to stand.

Exuberant at his victory, Smallwood said he is already thinking about how to spend his expected winnings--invest it in a money market fund, perhaps, or buy a hang-glider, or replace his 1963 Chevy. "I'm the happiest now that I've ever been in my life," he said. "My wife and I are happy. We don't feel old. We just do the things we want to do."