Attack on Pearl Harbor (14 page)

There simply were too few fighters for the first wave to employ fighter sweep tactics.

Close Escort

A second option would be to have the fighters remain with the bombers in a close escort role. In China, Japanese fighter pilots preferred to range freely and dogfight with the enemy, rather than to stick with a bomber formation. Close escort was simply not available in their doctrine or their mindset.

The Plan

The decision was to have the fighters accompany groups of bombers en route to the targets. The fighters would engage enemy fighters in the air or, in the absence of aerial opposition, strafe enemy airfields.

As the first wave flew south, groups would break off and head to their individual objectives.

The specific orders for the fighters are particularly noteworthy: “The targets of Fighter Combat Units will be enemy aircraft in the air and on the ground.” That wording reflects the Japanese belief in the superiority of the offensive. The order did not say, “Protect the bombers from enemy fighters.” Indeed, it directed the opposite: “In the event that no enemy aircraft are encountered in the air, the (Fighter Combat) units will immediately shift to the strafing of parked aircraft…”
³⁶

The fundamental Japanese fighter organization was a
shotai
of three aircraft, with three
shotais
combining into a
chutai
of nine aircraft. All the fighter formations assigned to each of the groups were from a single carrier, with the exception of the Kaneohe Field strike group that consisted of a mixture of
Shokaku
and
Zuikaku
fighters. This allocation preserved unit integrity, but maintaining unit integrity imposed a nearly even distribution of fighters across the formations that were disproportionate to the value of each formation.

For example, the torpedo bombers were expected to deliver 27 torpedo hits, enough to sink six battleships. The B5N Kates carrying AP bombs expected eight hits and perhaps to cripple one or two battleships. In other words, the torpedo bombers were three to six times as valuable as the high-altitude bombers. In addition, the torpedo bombers would be the most vulnerable. During their final run to target they would be flying singly, low and slow, in four long strings of bombers with each aircraft separated by hundreds of yards, beyond where their defensive machine guns could provide mutual support. The level bombers would be in five-ship elements with some degree of mutual protection.

These considerations should have caught the attention of the planners. Fighter cover should have been allocated to the torpedo bombers in proportion to their vulnerability and value. The torpedo bombers should have been wrapped in cotton wool and protected at all costs. Instead, the torpedo bombers, with 85% of the killing power, were protected by 20% of the fighters.

Even more inexplicably, the fighter
chutai
accompanying the torpedo bombers was to split off to attack the Marine Corps Air Field at Ewa, seven miles from Pearl Harbor. The torpedo bombers would make their final approach and attack
without any fighter protection over the harbor whatsoever
. While the Zeros were absent strafing airfields, the torpedo bombers could have been slaughtered.

This all was exacerbated by the fact that the fighters trained independently. They had not practiced with the bombers, so coordinated support was impossible.

The largest fighter unit was assigned to attack Kaneohe Field. This is inexplicable. Twelve of the available first-wave fighters (27%) were sent against an airfield fifteen miles from Pearl Harbor, to attack a PBY patrol wing. Granted, the “B” in PBY stood for “bomber,” and pre-war aviation theorists actually thought these large, slow, poorly defended aircraft could be a threat to surface ships. Even if they constituted a threat, the PBYs at Kaneohe were not an
immediate
threat. It would have taken hours to locate the Japanese carriers and load bombs for an attack. A first-wave attack on Kaneohe could not be considered as an anti-reconnaissance measure, since the Japanese fighters were to arrive well after the Americans’ dawn reconnaissance patrols were in the air. This target could have been deferred to the second wave. The primary concern of the first-wave fighters ought to have been enemy fighters, not reconnaissance aircraft.

In a plan featuring many unusual decisions, the most bizarre was that
more fighters were assigned to strike a wing of seaplanes than were assigned to ensure that the torpedo bombers reached their target
.

The primary mission of the fighters ought to have been to escort the B5N Kate torpedo bombers to the target and provide cover against enemy fighters, along with suppression of enemy air defense (SEAD) if the AA proved formidable (as it did). This was Japanese doctrine for attacking a fleet at sea—there is no reason why it should not have applied to attacking a fleet in port. After the torpedo bombers had successfully attacked, a process of only a few minutes if executed as planned, the fighters could have shifted to strafing airfields. But Japanese offensive propensities, along with their experiences in China, blinded them to the need to provide direct fighter support to the torpedo bombers.

The air groups from
Zuikaku
and
Shokaku
assigned to the Kaneohe strike were not held in high regard. Their air groups had only been recently formed out of the scrapings of available A6M Zero pilots. Much of their training in the months before the attack was in flying fundamentals, such as formation flying. It could be that they were shuffled off to the side and trusted to do little more than create some confusion, and delay the American reconnaissance effort.

No fighters (or bombers) were allocated for SEAD. It was as if the concept did not exist, or that the fighters had their own missions and would not be bothered to help the bombers along the way. “Combined arms” and “mutual support” were concepts absent from the Japanese lexicon.

The planners spread the available fighters nearly evenly over all the formations, regardless of the numbers or importance of those planes in the mission plan. The military proverb, “He who protects everything, protects nothing,” applies. If the American forces at Hawaii had been in their usual readiness and detected the approach of the strike, and if the US fighters had massed over Pearl Harbor to protect the fleet (as was their responsibility), it is likely that the torpedo bombers’ attack would have been thwarted.

One capability of their new fighter that the Japanese did not exploit was its incredible endurance. In the months before the beginning of the war the Japanese developed techniques to stretch the range of the A6M Zero to unheard-of lengths. Cruising at 115 knots at 12,000 feet, an A6M Zero with an average pilot at the controls could consume as little as 18 gallons per hour out of a normal fuel load of 182 gallons, giving ten hours in the air.
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First-wave fighters launched at 0600 could have remained over Oahu for hours after the second wave had departed, if asked to do so. First-wave fighters could have been posted over each of the airfields and remained for the duration of the attack, ensuring that nothing got off the ground until after the second wave had come and gone. On US carriers this was known as “double cycling,” and was usually done only with scout bombers on inner and outer AS patrols. US Fighters could be double-cycled after drop tanks were developed.

Evidently no thought was given to taking advantage of the A6M Zero’s endurance. Instead, the fighters went in to the attack, expended their ammunition immediately, and joined up at the strike rendezvous point so the bombers could navigate them back to the carriers. The plan allowed the Americans a hiatus in the attack, time to recuperate from the effects of the first wave, recover and rearm what fighters they had gotten aloft, and prepare for the next wave.

Bomber Allocation for the Main Effort

The Intelligence Foundation

The Japanese were blessed with extraordinarily good intelligence for their attack. The Japanese Navy assigned a reserve naval officer, Yoshikawa Takeo, a graduate of the Japanese naval academy who had been medically disqualified from active duty, as a member of the Japanese legation on Oahu. While posing as a diplomat, his true role was kept secret from the legation staff. His neglecting of his “duties” at the legation scandalized the regular diplomatic staff, as he traveled about Oahu under the guise of a gadabout.

Almost daily he traveled to a tourist overlook surveying the beauties of Pearl Harbor and counted the fleet, noting mooring locations. He recorded the fleet’s operating patterns. He determined the day of the week when most ships would be in port. He took tourist flights over the harbor, one on the 5th of December accompanied by two young ladies of questionable repute, a rather ingenious and amiable way to conceal intelligence activities. He attended open house events staged at the various bases, where he was allowed to wander about unsupervised. He worked in the kitchen at the Pearl Harbor Officer’s Club, with access to the base and the officers’ gossip. Attending a “Galaday” at Wheeler Field in August when the airdrome was dedicated, he inspected the facilities thoroughly.

Planners from the Naval General Staff also traveled to Hawaii aboard the civilian liner
Taiyo Maru
. This ship traveled along
Kido Butai’s
intended route to take weather observations, gauge the density of traffic (no ships sighted), and observe American reconnaissance (ineffective). At Honolulu they delivered an extensive list of questions to Yoshikawa regarding Pearl Harbor and its defenses.

Yoshikawa divided Pearl Harbor into numbered squares and transmitted the locations of ships. Periodic messages to the Naval General Staff in Tokyo, sent through diplomatic channels, included the specific anchorages and moorings occupied by the ships, along with listings of daily arrivals and departures.
Kido Butai
received one of these messages the day before that attack, with the information a day late due to being retransmitted from Tokyo. As
Kido Butai
approached Hawaii, Yoshikawa provided last minute tactical intelligence on anti-submarine nets at the entrance to the harbor (yes), anti-torpedo nets around the battleships (no), and barrage balloons (no).

The aviators had nearly exact information on the locations of moorings and berths and, more importantly, which normally hosted battleships and carriers. Each pilot was provided a map with the locations of their targets and the location of ground AA positions. They also were given aerial “Souvenir of Honolulu” photographs of the naval base. Copies would be found in aircraft shot down during the battle.
³⁸

The Japanese had a firm intelligence foundation upon which to plan and execute the attack.
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Operational Approach

Some of the most important decisions involved the overall concept of how the operation was to be executed, including the manner in which targets would be allocated to specific attackers, the attack order and timing, ingress and egress routes, and coordination.

Targets could be allocated in several ways. Under one option, specific aircraft could have been directed to hit specific targets. Alternately, a prioritization scheme could be used where the pilots were given general instructions regarding the types of targets to hit and in what order, with the aviators selecting their specific targets upon arrival. A compromise between the two would be for attackers to select specific targets out of an assigned area.

Each method has advantages and disadvantages.

Assigning aircraft to specific targets would give a better distribution of weapons over the intended targets, and would not require the aviators to make difficult target selection decisions when stress would be high. However, weapons could be wasted and confusion could result if the intelligence was inaccurate or if ships had moved since the last update. Pilots would still be required to recognize appropriate targets and avoid wasting weapons on inappropriate targets, something more difficult to achieve under combat conditions than might be suspected. Alternate targets could be pre-assigned, or the aviators could be given the freedom to independently find a target, or they could be directed to a marshalling area to serve as a reserve to be directed to a new target by the strike commander.