SPOKANE, WASH., JUNE 2 -- The Strategic Air Command waived restrictions on aerobatics to allow the sort of maneuvers being rehearsed by a KC135 tanker jet just before it crashed March 13, killing seven crew members, according to a published report.

The waiver was granted in January by SAC headquarters at Offutt Air Force Base in Nebraska and applied to crews at Fairchild Air Force Base here and at four other bases, according to Air Force documents obtained under the Freedom of Information Act.

Details of the documents were disclosed today in the Spokesman-Review.

All SAC demonstration teams have been grounded pending investigations into the tanker crash.

According to the documents, the waiver allowed the crews to perform low-altitude refueling simulations, fly two aircraft closer than two miles from the path of another plane and fly demonstrations lower than 500 feet.

Since the crash of the Thunderhawks demonstration team at Fairchild, SAC and Fairchild officials have stressed that the air show they were developing involved no maneuvers beyond the planes' capabilities.

Gen. John T. Chain Jr., head of SAC, said SAC wants to resume the air demonstrations if investigators determine that the maneuvers can be done without causing another accident.

Plans for Fairchild's air demonstration required a four-engine KC135, designed as a high-altitude, high-speed refueling plane, and a B52 bomber to perform banks up to 60 degrees at low altitude, according to the documents.