It also became the home of the Manila Air Depot, which provided maintenance support for all Army and Navy aircraft in the Philippines.
Due to its proximity to Manila, it also was the primary command and control base for the Philippine Department Air Force.
On 24 October 1940, President Franklin Roosevelt signed an executive order requisitioning all the undelivered P-35s sold to Sweden and impressing them into the USAAC.
[4] In September, the 17th was moved to the still uncompleted Nichols Field when word was received that space at Clark was needed for B-17 Flying Fortresses of the incoming 19th Bombardment Group.
[4] With the large number of units being deployed to the Philippines during the buildup of forces in the summer and fall of 1941, the 3rd, 17th and 20th Squadrons were reassigned to the new 24th Pursuit Group, which was activated at Clark Field.
From 30 November to 6 December all squadrons underwent intensive training in day and night enemy interception and air-to-air gunnery.
[4] On 8 December at about 03:30 the commercial radio station at Clark Field intercepted a message from Pearl Harbor, Hawaii about the Japanese attack there.
[4] At approximately 09:30, a large formation of Japanese bombers was spotted over Lingayen Gulf reported heading towards Manila.
The interception was not successful, as the bombers turned to the northeast and attacked Baguio and Tagagarau then headed north off the radar.
P-40 Warhawks took off from Nichols Field to intercept enemy aircraft spotted on radar, but failed to make contact.
The planes would be employed mainly as reconnaissance aircraft to replace the 2d Observation Squadron, which was made inoperable after being mostly destroyed on the ground.
[7] On the morning of 23 December the Japanese made a landing in San Miguel Bay along the east coast of Lingayen Gulf.
[9] After their defeat in the Battle of Leyte Gulf, the Japanese Navy reconstituted itself as a land force and positioned their naval guns in Fort Mckinley to halt the Allied advance on Luzon.
During the Battle of Luzon, Nichols Field was recaptured by elements of the Sixth United States Army when paratroopers of the 11th Airborne Division attacked the base on 4 February.
Four days' effort had effected little reduction in the amount of Japanese fire originating from the Nichols Field defenses.
In fact, the volume of fire from Japanese naval guns of various types was still so great that one infantry company commander requested: "Tell Halsey to stop looking for the Jap Fleet.
[12] When direct communication began, the 11th Airborne Division and the XIV Corps quickly co-ordinated artillery fire plans and established a limit of fire line to demark their support zones about midway between Nichols Field and the Manila city limits.
For the time being, Griswold directed Swing, the 11th Airborne Division would continue to exert pressure against the Japanese at Nichols Field but would mount no general assault.
On 19 August 1945, a sixteen-man Japanese delegation led by Japanese Lt. General Kanabe secretly left Kazarazu air base, Japan, in two Mitsubishi G4M "Betty" bombers, painted white with green crosses, as ordered by General MacArthur, to comply with the surrender of the Philippines at Manila.
During the initial meeting, the Japanese were instructed to have 400 trucks and 100 sedans at Atsugi Airfield, Japan, in readiness to receive the 11th Airborne as occupation forces.
There were also 300,000 well-trained troops on the Kanto Plain of Tokyo, so MacArthur moved the landing for the 11th A/B to 28 August; five days later than originally planned.