It is unsurprising, then, that MacArthur excluded USAF aircraft from the airspace over the Inchon Landing in September 1950, instead relying on Marine Aircraft Group 33 for CAS. In December 1951, Lt. Gen. James Van Fleet, commander of the Eighth U.S. Army, formally requested the United Nations Commander, Gen. Mark Clark, to permanently attach an attack squadron to each of the four army corps in Korea. Though the request was denied, Clark allocated many more Navy and Air Force aircraft to CAS. Despite the rocky start, the USAF would also work to improve its coordination efforts. It eventually required pilots to serve 80 days as forward air controllers (FACs), which gave them an understanding of the difficulties from the ground perspective and helped cooperation when they returned to the cockpit. The USAF also provided airborne FACs in critical locations. The Army also learned to assist, by suppressing anti-aircraft fire prior to air strikes.