A House International Relations subcommittee yesterday agreed with the State Department that the Carter administration was not legally required to report to Congress on the U.S. military airlift to Zaire in May.

Accordingly, the international security subcommittee rejected a resolution offered by Rep. Paul Findley (R. Ill.) that would have charged the administration with a violation of the War Powers Act for failing to file a formal report on the Zairian operation.

The War Powers Act, a joint resolution passed over former president Richard Nixon's veto in 1973, requires the president to report to Congress within 48 hours when American troops "equipped for combat" have been sent into a foreign nation, or when any American soldier is sent to a spot where hastilities are "imminent".

The Carter administration did not make such a report last May when U.S. C141 transports, manned with Air Force crews carried military cargo and French and Belgian military personnel into Zaire to help defend against Katangan tribesmen who had invaded Zaire's Shaba province.

Nor was there a formal report in June when Air Force planes helped ferry Morrocan soldiers attached to an international peacekeeping force into Zaire.

On both occasions, however, the administration told congressional leaders beforehand of the proposed airlift operations.

Findley and Rep. James Leach (R-Iowa), wrote to the State and Defense departments questioning the decision not to file a formal report under the 1973 Act. The departments replied that the Zaire airlift was not covered by the war powers legislation.

In testimony before the international security subcommittee yesterday, State Department legal adviser Herbert J. Hansell said the May airlift was exempt because the Air Force crews were armed only with revolvers - and thus were not "equipped for combat" - and because the Americans never were nearer than 130 miles to the Shaba fighting.

The June airlift was exempt, Hansell said, because the Katangans had withdrawn by the end of May and Zaire was no longer a site of open war.

Findley, quoting Judge Learned Hand on the importance of following the spirit, as well as the letter, of legislation, called that an "incredibly narrow interpretation" of the incident which was "little more than a subterfuge of the law."

But the subcommittee members, including Chairman Clement Zablocki (D-Wis.), who was the chief sponsor of the 1973 Act, disagreed. All said they agreed that the Zaire operation was not covered by the act, although Rep. Ponathan Bingham (D-N.Y.), called the issue "a close question."

When Findley saw that he had no support on the subcommittee, he withdrew his proposed resolution.

The precedent established yesterday's subcommittee action is less clear.

"It is a very critical precedent for the War Powers Act". Findley said. "There's no doubt that a future president will take this very narrow interpretation to avoid reporting on something he doesn't want to talk about."