Собственно, на фото все написано...
Вопрос "зачем?!", естественно, не дает покоя.
F-4C "Phantom II" ВВС США с подвеской в общей сложности 15 пулеметов Миниган.
Дополнение от p_d_m
"An F-4C carrying clusters of GAU-2B/A Miniguns was being evaluated by McDonnell and the USAF at Eglin AFB. At the time this photo had been taken the aircraft had been flown in this configuration. Additional tests with 15 Miniguns were planned though the thinking was that in combat operations the aircraft would only carry up to 9 guns - allowing it to carry external tanks on the outer wing stations."