Three members of the air traffic controllers union in Northern Virginia received 10-day jail terms yesterday from a federal judge for encouraging union members to stay off the job in last August's nationwide strike.

"The government has made its point, but the court's point is a little different: the integrity of its orders," said District Judge Albert V. Bryan Jr. Bryan accepted pleas of no contest from all three last month to charges of criminal contempt for disobeying an Aug. 3 back-to-work order.

In a related development, District Judge Oren R. Lewis reduced fines for civil contempt yesterday against individual leaders of the Professional Air Traffic Controllers Organization in eastern Virginia, but left standing $250,000 fines imposed on each of five union locals in the state.

A PATCO lawyer, Washington attorney Kenneth Conklin, later characterized the fines against the locals as "almost ludicrous."

Conklin argued earlier before Bryan that all three who pleaded no contest to criminal contempt were "pillars of the community" who already had punished themselves and their families by giving up their $40,000-a-year jobs as controllers.

"They made one mistake -- maybe they were overwhelmed by what they believed -- but they made one mistake: They didn't go back to work," Conklin said.

Conklin said several former controllers have taken part-time jobs in service stations, department stores and teaching positions to make ends meet since being frozen out of employment as controllers by President Reagan.

All three men sentenced by Bryan -- John F. Thornton, president of the PATCO local at National Airport; Thomas S. Galloway, union head at the Air Traffic Control Center in Leesburg, and William Lombardi Jr., a former controller at Leesburg -- were led away later in handcuffs and leg shackles by federal marshals.

They will serve their sentences at the Fairfax County jail.

In yesterday's second hearing, Judge Lewis reduced $5,000 fines sought by the government against Galloway and Thornton to $1,000. Lewis also cut a proposed $5,000 fine against William Sly, head of PATCO at Dulles International Airport, to $3,000.

A $4,000 penalty proposed for Gene Bragg, PATCO head at Newport News, who followed Lewis' suggestion last summer to return to work, was reduced to $500. "Bragg did do what I wanted 'em all to do," Lewis said.

A fifth union leader, Stephen Wallaert of Norfolk, was jailed by Lewis for a week in August on contempt charges and was not fined.

The outspoken Lewis referred several times yesterday to the former controllers' employment contracts with the federal government -- which included a no-strike clause -- as a "solemn oath."

"They did everything they could to encourage others not to go back to work," Lewis said.