[5] The 20th began to fly combat missions in the Philippines from the morning of 8 December 1941, when Japanese aircraft were erroneously reported to be approaching Luzon.

As part of the purchase, an agreement was made between the West German government and the United States for the USAF to conduct basic F-4 transition and instructor training.

[6][1] Under this agreement, the USAF reactivated the 20th as the 20th Tactical Fighter Training Squadron (20th TFTS) at George AFB, California on 1 December 1972.

It also supported members of the Luftwaffe 1st Training Squadron, under which German Air Force personnel were assigned while in the United States.

Later, as the F-4F was put into production by McDonnell, the F-4Es were replaced with twelve West German F-4Fs were that were given the unofficial designation of TF-4F while they were being used to train Luftwaffe crews in the United States.

The 20th was inactivated, and the training was reassigned to the 9th Fighter Squadron, 49th Operations Group at Holloman Air Force Base, New Mexico.

By the early 2000s, the German Air Force was phasing out the Phantoms in favor of the Panavia Tornado IDS and Eurofighter Typhoon interceptors.

The F-4F/ICEs were retired and the program at Holloman was officially ended on 20 December 2004[9] and its aircraft were transferred to the Aerospace Maintenance and Regeneration Center.

[12] The last of the Luftwaffe F-4F Phantom IIs in Germany were retired on 30 June 2013 by JG 71, although four aircraft remain in service for aerial demonstrations.