MacArthur to implement Rainbow 5, Brereton was ordered to have a strike in readiness for later approval.Correll, "Caught on the Ground". Through a series of disputed discussions and decisions, authorization for the first raid was not approved until 10:15 am local time for an attack just before sunset, with a follow-up raid at dawn the next day. In the meantime, Japanese plans to attack Clark and Iba Fields using land-based naval bombers and Zero fighters were delayed six hours by fog at its Formosa bases, so that only a small scale Japanese Army mission attacked targets in the northern tip of Luzon. At 08:00 am, Brereton received a phone call from Gen. Henry H. Arnold warning him not to allow his aircraft to be attacked while still on the ground. FEAF launched three squadron-sized fighter patrols and all of its serviceable bombers on Luzon between 08:00 and 08:30 am as a precautionary move. After MacArthur gave Brereton the authorization he sought at 10:15 am, the bombers were ordered to land and prepare for the afternoon raid on Formosa. All three pursuit squadrons began to run short on fuel and broke off their patrols at the same time. The 20th Pursuit Squadron's Curtiss P-40B interceptors patrolled the area while the bombers landed at Clark Field between 10:30 and 10:45, then dispersed to their revetments for servicing. The 17th Pursuit Squadron, based at Nichols Field, also landed at Clark and had its aircraft refueled while its pilots ate lunch, then put its pilots on alert shortly after 11:00. All but two of the Clark Field B-17s were on the ground. At 11:27 am and 11:29 am, the radar post at Iba Field detected two incoming raids while the closest was still 130 miles out. It alerted FEAF headquarters and the command post at Clark Field, a warning that reached only the pursuit group commander, Major Orrin L. Grover, who apparently became confused by multiple and conflicting reports. The 3rd Pursuit Squadron took off from Iba at 11:45 with instructions to intercept the western force, which was thought to have Manila as its target, but dust problems during its takeoff resulted in the fragmentation of its flights. Two flights of the 21st Pursuit Squadron (PS) at Nichols Field, six P-40Es, took off at 11:45, led by 1st Lt. William Dyess. They started for Clark but were diverted to Manila Bay as a second