 At 04 : 30 on 4 June , Nagumo launched his initial attack on Midway itself , consisting of 36 Aichi D3A dive bombers and 36 Nakajima B5N torpedo bombers , escorted by 36 Mitsubishi A6M Zero fighters . At the same time he launched his 8 search aircraft ( one from the heavy cruiser Tone launched 30 minutes late ) . Japanese reconnaissance arrangements were flimsy , with too few aircraft to adequately cover the assigned search areas , laboring under poor weather conditions to the northeast and east of the task force . As Nagumo 's bombers and fighters were taking off , 11 PBYs were leaving Midway to run their search patterns . At 05 : 34 , a PBY reported sighting 2 Japanese carriers and another spotted the inbound airstrike 10 minutes later . 
