Vice Admiral Nagumo faces his first problem

Vice Admiral Nagumo's first attack wave commander had reported at 0700 hours that the airfield at Midway was still operational and that anti-aircraft fire had been intense. This was bad news for the Japanese commander because one of his primary tasks was to knock out this airfield so that the transports of the Midway Invasion Force could approach safely and land Japanese troops on the American atoll. The attacks by Midway-based bombers on his carrier force from 0705 that morning convinced Nagumo that a second strike at Midway was essential to render the airfield unusable for attacks on Japanese troop transports. The Kate level bombers bombers held back from the first strike at Midway were still parked in their hangars below the flight decks of Akagi and Kaga, and these bombers were armed with torpedoes that were useless for a strike at land installations such as those on Midway. Nagumo now faced his first difficult decision of this day. Should he launch a second attack on Midway as soon as possible? That would involve replacement of all torpedoes on his level bombers with fragmentation bombs, and tie up his flight decks for about an hour while the aircraft of the second attack wave were rearmed, moved up to the flight decks, and prepared for launching at Midway.

Between 0705 hours and 0814 hours on the morning of 4 June 1942,five successive American air attacks from Midway Atoll put the commander of Japan's First Carrier Striking Force under pressure of a kind that he is unlikely to have experienced before.
Those five attacks formed part of a continuing sequence of eight American air attacks that combined to throw Japan's First Carrier Striking Force off balance, and keep it off balance and vulnerable from 0705 to 1022 when the Dauntless SBD dive-bombers from Enterprise and Yorktown were able to exploit that vulnerability.

Another alternative was to hold the Japanese bombers on their carriers in readiness to repel a possible American naval counter-attack, and await the return of the first attack wave. The aircraft of the first attack wave could then be refuelled and rearmed for a second strike at Midway. Although warships of the United States Pacific Fleet were not expected by Admiral Yamamoto to arrive at Midway in response to the Japanese attack before 6 June at the earliest, Nagumo was still concerned that Japanese intelligence had provided him with no information on the whereabouts of American aircraft carriers.

After weighing the alternatives, Vice Admiral Nagumo made a fateful decision to use the torpedo and dive-bombers held back on his four carriers for a second strike at Midway. At 0715, as the second American torpedo bomber attack from Midway was ending, Nagumo ordered the rearming of all torpedo bombers with fragmentation bombs. In the hangars of Akagi and Kaga, the sweating crewmen worked frantically to replace torpedoes with fragmentation bombs because Nagumo intended to launch his second attack wave at Midway before the first wave returned to the Japanese carriers. If normal Japanese practice was followed, the dive-bombers would have their fragmentation bombs fitted after they had been lifted to the flight decks and while their engines were being warmed for take-off.

Continuing American torpedo and bombing attacks prevent Nagumo "spotting" strike bombers on his flight decks

Although Nagumo intended to launch the bombers in his hangers in a second strike at Midway as soon as possible, there was a major impediment to those bombers being lifted to the flight decks and prepared for launching at Midway or anywhere else. On Japanese carriers in 1942, the process of moving fully armed strike bombers from hangar to flight deck and preparing them for take-off normally required a minimum of forty minutes. It was simply not possible for Nagumo to "spot" a bomber strike on his flight decks while the four Japanese carriers were under continuing attack by American aircraft. The flight decks had to be kept clear of strike bombers in order to allow the combat air patrol Zeros to be recovered, refuelled, rearmed, and relaunched to defend their carriers.

Author's Note

Assuming the Japanese carrier level bombers were already armed with torpedoes, preparation for a strike involved moving aircraft in their hangars to the lifts, "spotting" them on the flight deck, unfolding wings, warming up the engines, final briefings for pilots, and pre-flight checks. The dive and level bombers would be armed with bombs on the flight deck while their engines were warming up. The Midway volume Midowei Kaisen (1971) of the official Japanese war history Senshi sosho declares at page 289 that this procedure "would have taken no less than forty minutes.." Between five to ten minutes would have to be added for the launch of the full strike.

The critical impact of the continuing American torpedo and bombing attacks in frustrating Nagumo's ability to "spot" strike bombers on his flight decks between 0705 and 1022 hours has been acknowledged by Jon Parshall, an internationally recognised expert on Imperial Japanese Navy operational doctrine:

"Taken together, it is apparent that spotting a twenty-one plane strike for launch would take around forty minutes total, and another five to ten minutes would be required for the launch....Thus if Nagumo was to attack the American strike force, he needed to find an unbroken forty-five minute window of opportunity on all four flight decks during which to spot and then launch his strike".

"Doctrine Matters: Why the Japanese Lost at Midway", published in the Naval War College Review 2001 (at pages 2-3 of the web version).

First news from the cruiserTone's scout seaplane

While the Japanese Kate level bombers were being rearmed with fragmentation bombs in their hangars, the following signal was received at 0728 from scout seaplane Number 4 from the cruiser Tone:

"Sight what appears to be ten enemy surface ships, in position 10 degrees distance 240 miles from Midway. Course 150 degrees, speed over 20 knots".

The Tone scout seaplane had located a fleet of warships about 240 miles (384 km) north of Midway Atoll and heading in a south-easterly direction. Vice Admiral Nagumo had no doubt that the warships were American and he was alarmed to learn that enemy warships were positioned so close to his carriers. He discussed with his staff officers the best course of action. Lieutenant Commander Ono, the staff intelligence officer, plotted the position of the enemy fleet and placed it only 200 miles (320 km) from the Japanese carriers. The neutralisation of Midway Atoll had been fixed by Admiral Yamamoto as being Nagumo's top priority, and the continuing attacks by Midway-based aircraft reinforced that priority. The second wave attack on Midway had to go forward as planned, but it was decided that the First Carrier Striking Force should also prepare to meet a threat from an American fleet. At 0745, Nagumo issued the following order to his carriers:

"Prepare to carry out attacks on enemy fleet units. Leave torpedoes on those attack planes which have not as yet changed to bombs."

This compromise would leave about half of the Kates in the hangars of Akagi and Kaga equipped with torpedoes and the rest of the Kates in those hangars equipped with fragmentation bombs for the second wave attack on Midway. At 0747, Nagumo tersely ordered the Tone scout to identify the American warship types and maintain contact.

At 0748, Soryu signalled the arrival of another attack wave from Midway. This attack was launched by Major Lofton R. Henderson's Dauntless SBD-2 dive-bombers of VMSB-241. Again, the Japanese carriers were forced to scatter and take their protective Zero screen with them.

At 0758, Nagumo received the following message from the Tone scout:

"...the enemy is on course 80 degrees, speed 20 knots".

At 0809, the Tone scout reported:

"Enemy ships are five cruisers and five destroyers".

American cruisers and destroyers posed no significant threat to the powerful carriers and battleships of the First Carrier Striking Force, and Nagumo's fears were eased.

The B-17 heavy bombers from Midway had arrived over the Japanese carrier fleet at 0814, and dropped their bombs on Hiryu and Soryu. During the B-17 attack, returning aircraft from the first Midway attack wave began arriving over the Japanese carriers and were waved off as the carriers undertook frantic evasive manoeuvres. Both Hiryu and Soryu had been bracketed by the B-17 bombs, but emerged unscathed from the attack. Vice Admiral Nagumo was feeling more confident as each attack from Midway was repulsed. They had easily fended off several attack waves by American bombers from Midway, and his ships had suffered no significant damage. However, other matters were beginning to trouble the commander of the First Carrier Striking Force at this moment.

Vice Admiral Nagumo finds himself under pressure

The resolute American counter-attacks from Midway had placed the powerful First Carrier Striking Force and its commander under pressure of a kind that they were unlikely to have experienced before when slaughtering poorly trained Chinese pilots in Japan's unprovoked and brutal war against China. To Japanese Navy officers, the American torpedo pilots were not behaving as they were suppose to. It had been drilled into them that Americans were poor fighters and lacked discipline. And yet, the American torpedo pilots had attacked them, and pressed home their attacks resolutely without fighter protection. It must have seemed to them that the American torpedo pilots had sacrificed themselves with the selfless courage of samurai. This was extraordinary behaviour from a despised enemy, and likely to be very unsettling for the Japanese.

Although failing to inflict any significant damage on the Japanese carriers, the attacks pressed home by successive waves of American bombers from Midway had forced the Japanese carriers to undertake evasive manoeuvres that broke up their tight battle formation and scattered the Japanese warships and their protective fighter patrols. With his fleet now in disarray, Vice Admiral Nagumo needed time to regroup his scattered carriers and their protective fighter patrols. He needed time to prepare and launch a second attack wave at Midway to put the airfield out of action. The aircraft from his first attack wave were returning. Many of these aircraft were low on fuel and some were badly damaged. Nagumo needed time to recover these aircraft, and that was impossible while the Japanese carriers were manoeuvring wildly to avoid American air attacks. Nagumo and his staff officers were off balance and unsure of the direction from which the next attack might come.

Alarming news from the cruiserTone's scout aircraft

At 0820, the Tone scout reported again, and this time the news was electrifying for those on Akagi's bridge:

"Enemy force accompanied by what appears to be aircraft carrier bringing up the rear".

Deeply alarmed by the presence of an American carrier so close to his own force, Nagumo ordered the arming of all bombers with torpedoes and armour-piercing bombs. Being crammed with torpedoes, bombs, and aircraft fuel, carriers were highly combustible. A quick first strike against the American carrier was imperative. However, protecting the bombers in that strike from American carrier fighters had become a problem. To protect his four carriers against a succession of attacks from Midway, Nagumo had allowed a massive combat air patrol of almost fifty Zero fighters to be placed above his widely dispersed fleet. Nagumo had started with eighty-four Zeros on his four carriers, and now he had none in reserve to escort bombers on an immediate strike at the American carrier reported by the Tone scout. He could recover some of the Zeros defending the carriers, but they would have to be refuelled and rearmed before they could escort bombers.

Vice Admiral Nagumo faces a second difficult decision

Vice Admiral Nagumo's next difficult decision on this day was whether to launch a strike at the American carrier force as soon as all bombers aboard his carriers had been rearmed and were ready to attack warships, or delay the launch until the aircraft from the first Midway strike had returned to his carriers and been recovered. While considering these alternative courses of action, Nagumo's deliberations were interrupted by Rear Admiral Tamon Yamaguchi, the aggressive commander of Carrier Division Two, comprising carriers Hiryu and Soryu. Yamaguchi had followed closely the reports from the Tone scout seaplane. He had thirty-six Type-99 Val dive-bombers in his hangars and he believed that it was extremely dangerous to delay launching an attack on the American carrier sighted by the Tone scout. Yamaguchi signalled Nagumo:

"Consider it advisable to launch attack force immediately."

Nagumo was under pressure to make a decision quickly. Some aircraft from his first attack wave had returned from Midway, and were circling their carriers. The fighters were running low on fuel and some of the planes were badly damaged. To permit the returning attack wave to be recovered, he would have to keep his flight decks clear. It would take him at least forty-five minutes to "spot" a bomber strike on his flight decks and launch it at the American carrier. During that time, many of his first attack wave aircraft would run out of fuel and have to ditch in the sea. For Nagumo, the clinching argument against an immediate bomber strike was the lack of any readily available Zero fighters to escort them to the American carrier. The heavy toll inflicted by his fighters on the unescorted American bombers from Midway convinced Nagumo that sending out strike bombers without a fighter escort was unacceptable.

Vice Admiral Nagumo now made a second fateful decision, which was to delay launching an attack on the American carrier task force until he had recovered his aircraft from the first Midway strike.

When all of the aircraft of the first attack wave had been recovered, Nagumo intended to retire northwards to avoid further air attacks from Midway. This would enable him to regroup his scattered carriers and prepare a massive attack to destroy the American carrier and its escort warships. At 0837, Akagi began to recover aircraft from the first Midway attack wave. When the last returning aircraft from Midway had touched down on its carrier at 0917, the First Carrier Striking Force immediately made a 70-degree change in course to the north-east. On all four Japanese carriers frantic preparations were under way to launch a massive strike at the American carrier force discovered by the Tone scout seaplane. Those preparations were fated never to be completed. At 0920, preparations for the Japanese strike were interrupted by the arrival of fifteen American Navy torpedo bombers that had been launched from the carrier USS Hornet. Torpedo Squadron Eight (VT-8) was led by Lieutenant Commander John C. Waldron, USN.