Federal investigators have found the identification badge of a fired USAir employe who is believed to have caused the Dec. 7 crash of Pacific Southwest Airlines Flight 1771 by shooting the pilots, the San Diego Union reported yesterday.

The badge, reported found in the wreckage from the plane, apparently provides further explanation of how David A. Burke bypassed the airline's security checkpoint and smuggled a .44-cal. handgun onto the plane. Burke was fired Nov. 19 for allegedly stealing $69 worth of liquor receipts.

The FBI refused comment on the report about the badge. The newspaper quoted an unidentified source as saying the badge "with a photo was definitely found" in the wreckage.

Investigators say they believe Burke, 35, carried the gun on board the plane after being waved through by security officers who recognized him as an airline employe. They contend that Burke may have killed the supervisor who fired him, Raymond F. Thomson, then entered the cockpit, where he may have killed one or both pilots.

The plane, with 43 people aboard, plummeted nose-first from an altitude of 22,000 feet and crashed in a hilly pasture 15 miles northwest of San Luis Obispo less than two minutes after the pilots radioed to air traffic controllers that they had heard gunfire in the cabin.

After the crash, USAir officials said Burke had surrendered his badge to the airline when he was fired. Dave Shipley, a USAir spokesman, said yesterday "it's not all that uncommon" for an employe to have a second badge if the first one is reported lost or misplaced.

"You're supposed to have a badge to bypass security," he said.

The FBI has recovered the gun and a final, unsigned note addressed to Ray, scrawled on the back of an airsickness bag, from the crash site.

In San Luis Obispo, a funeral service is planned today at the San Osos Cemetery for 28 victims of the crash, a PSA spokesman said.

"There will be 28 caskets and 28 graves," Sam Douglass, a local funeral director told the Associated Press. "It will not be a mass burial. The only difference is we don't know for now whose remains are inside the caskets."

The remaining victims of the 43 people on board the flight have been identified, said Bill Hastings, a spokesman for PSA. The airline will pay for the funeral and a granite and bronze marker with the names of the victims.

The remains of the victims are documented, Douglass said. If the victims are identified later, the remains can be retrieved and returned to relatives.