U.S. involvement in the fighting in Zaire is apparently moving beyond the very limited boundaries announced by the White House on Friday.

A Pentagon spokesman said yesterday there are now "considerably less than 100" Americans on the ground at three airports in Zaire, coordinating landlings of 18 C141 Air Force transport planes and one huge Lockheed C5, the world's largest plane.

White House press secretary Jody Powell said on Friday that "the only place we wil be putting people on the ground will be a dozen or less people in Kamina (Airport) to maintain communications facilities and equipment to offload fuel."

There was no indication that U.S. personnel are involved in any actual fighting, and the Pentagon spokesman stressed that there is no U.S. combat role.

He said the dozen men Powell referred to Friday were fuel unloaders. Other personnel in Zaire now include airplanes unloaders, crews, and an aircraft landing and control teams, he said.

Despite the administration's expressed intentions not to become involved in the fighting on Zaire, there is great sensitivity in Congress and elsewhere to the possibility of being drawn incrementally, and without any formal decision, into foreign conflicts.

"Vietnam showed the unwisdom of getting deeply involved in a conflict thousands of miles from our own shores without our own U.S. security interests being involved," Senate Majority Leader Robert C. Byrd (D W. Va,) commented at his regular Saturday press conference.

There was some confusion yesterday about the actual extent of American involvement. When a Pentagon spokesman was asked to reconfirm that there are "less than 100" Americans in Zaire, the spokesman spent more than an hour calling back and forth to administration officials.

He eventually said that he did not want to get into a "numbers game," but that there are "considerably less than 100" Americans there.

As of midday yesterday, the C141s had flown 21 missions in support of French and Belgian operations to rescue Europeans trapped in the Kolwezi mining region, the Pentagon said.

The cargoes included light vehicles, fuel supplies, communications equipment, and general military supplies, according to the Pentagon.

The 'planes flew from Brussels and Corsica to airports at Kamna, Kinshasa, said Lumumbashi, the spokesman said.

The giant C5 is transporting to French troops a fuel truck too large for a C141, a spokesman said.

Meanwhile, the two battalions of the 82nd Airborne Division placed on alert Thursday were returned to normal duty yesterday.