The United States will soon send 12 F4E fighter-bombers to Egypt to train with the Egyptian air force in an attempt to dramatize how quickly the American military could come to the aid of countries in the Mideast.

The planes will be accompanied by 560 U.S. Air Force personnel, 400 of them to fly and service the aircraft and the rest to set up American housing and other facilities at an Egyptian air force base west of Cairo.

Administration officials said yesterday that the Air Force contingent would leave for Cairo next month and remain for about 90 days. It would be the largest such U.S. force sent to Egypt since President Anwar Sadat ejected his Soviet military advisers in 1972.

The U.S. airmen will take with them landing mats, barracks and other facilities to show how quickly the United States could establish a military base in a distant region, including the Persian Gulf.

Once in place at the Cairo West base, the U.S. pilots will train with Egyptian ones, who also fly F4s. Sadat has 35 F4s, the backbone of his otherwise crippled air force.

Although the United States has agreed to sell Sadat 40 new F16 light fighters, the first of those will not be delivered until April 1982 under the Pentagon's current timetable.

One government official predicted the presence of the American squadron will underscore the U.S. committment to Sadat at a time the fate of the Mideast peace treaty is in doubt and will have the practical benefit of training Eyptian pilots to greater proficiency.

The U.S. and Egyptian pilots will fly their F4s together, using the same ranges in live test firings. Presumbly there will be mock dog fights as well. r