7. GENERAL

In their campaigns to date, the Japanese have used bombers, fighters, and reconnaissance planes to assist the forward elements and to "soften" opposition. Targets for their aircraft include troops and installations in the lines of communication and exposed elements of the combatant forces such as roadbound congested transport columns, and command posts.

The Japanese air force not only protects the Japanese land forces, their bases, their lines of communication, and their concentrations, but in every operation it also gives prompt, close, and sustained support and cooperation to the ground forces.

The task force commanders have full control over all their weapons, and the necessary aircraft for the task are just additional weapons for the commander to employ. The commander is presumed to know the proper use of his air weapons even as he knows the use of his infantry or artillery. The Japanese regard the plane as an indispensable weapon with which to assist military operations. It might be said that they look on it as an airmobile battery, or, in its reconnaissance uses, as a pair of flying, long-range binoculars.

Before committing his forces to battle, the Japanese army commander has large air formations assigned to him and placed under his direct command (men, officers, and planes). He, in turn, often delegates command to smaller air units down to regimental commanders.

When not rendering close support to the ground forces, Japanese air units perform independent missions.

A Japanese manual says: "It is not cooperation we should seek—it is coordination we must make certain."

8. ATTACK TECHNIQUES

a. Fighter Planes

Practically all Japanese fighter planes have been equipped with an extra, detachable gasoline tank which enables them to fly long distances. The tank may be dropped during combat to lighten the plane load.

Besides strafing the airdromes of the opposition, the Japanese consistently and thoroughly ground-strafe the perimeter of airdromes to a depth of 30 to 50 yards inside any surrounding trees and generally with incendiary bullets. This ground-strafing is never done without thorough reconnaissance and careful planning. Runways are avoided so that they can be used later.

Japanese fighter squadrons, upon entering combat, frequently divide into two sections, one section flying low to tempt the opposing planes to dive and the other remaining high to dive on the opposition aircraft.

Diving out of clouds in the initial attack on the Philippines, Japanese fighters made a stern attack on the United States bombers and pulled out with a steep climbing turn, which offered the planes as good targets.

At Kota Bharu, four type 0 fighters, approaching in echelon formation at about 2,000 feet, peeled off into a steep dive to make an organized front-gun attack. The guns were fired from 1,500 feet and continued until the planes pulled out at low altitude. After the initial dive each plane appeared to act independently.

In another attack by 15 to 20 naval type 96 Mitsubishi seascouting fighters, some of the planes peeled off into a maneuver resembling a spin or aileron turn. They straightened out into a 70° dive with a very sharp pull out at about 1,000 feet. They dived a second time in a similar manner after gaining sufficient height.

In the Philippines, three Japanese 0 fighters used the following tactics on dispersed ground planes:

The fighters appeared from directly out of the sun at an altitude of not more than 300 feet. They opened fire immediately, dropping their noses a little and coming as low as 100 feet over the targets. After this first pass, the formation broke up and each plane selected a target and stayed with it, either circling after each run to come out of the sun or crisscrossing over the target. The attack lasted about 10 minutes.

The following tactics were used by nine Japanese 0 fighters against a formation of nine United States B-17E bombers:

Three of the Japanese fighters got on line in front of the bomber formation and made direct individual frontal attacks on the flight leader's ship while the remaining six attacked the rear ships of the formation. Throughout the attack, which lasted about 20 minutes, these tactics were repeated without variation. When the bomber formation leader was forced out of position, the three fighters continued the attack on the plane which replaced the leader. The Japanese pilots broke off frontal attacks in various ways, sometimes rising over the bombers and sometimes ducking underneath. Only once did they come in very close. Although four of the nine attacking planes were shot down, the remainder continued the attack until the bombers reached a thick cloud cover.

In Malaya, Japanese army fighters used a diamond of four planes as a basic unit, while naval fighters employed a narrow-angled, unsymmetrical V formation of three or five planes. Often the formation leader pulled out when encountering opposing aircraft and took no part in the actual combat. Presumably he directed the other fighters by radio, with which most recent Japanese planes are equipped.

A common fighter-plane formation used for ground attack is a V of three planes flanked by echelons of two planes each—a total of seven planes. When no opposition is encountered from fighter aircraft, three of the four planes constituting the flanking echelons close in and form a second V behind the first, and the extra plane follows in a position of high-covering protection. If fighter opposition is encountered, it is met by one or both echelon pairs, while the V formation of three planes executes the planned attack against ground forces.

b. Bomber Planes

(1) Horizontal bombing.—The tactical unit for horizontal bombing consists of nine planes. This type of attack usually precedes torpedo bombing. The aircraft attack at a height of about 12,000 feet, in close line abreast, and drop their bombs simultaneously on signal.

(2) Torpedo bombing.—The tactical unit for this type of bombing also consists of nine planes. The usual tactics are for the formation to lose altitude gradually, out of gun range, and approach the target in a loose column, deploying into a wedge or ragged diamond formation for the attack. The torpedoes are loosed at an average distance of 1,500 yards from the target, although some were dropped at 300 yards. Altitudes at the time of dropping the torpedoes varied up to 300 feet. Only individual attacks were made and always with complete disregard for antiaircraft fire.

(3) Dive bombing.—The dive is shallow—to date the Japanese have made no vertical dives. In the attack on Hawaii, the angle of glide was between 45° and 50°. The bombers begin the glide at a height of 3,000 to 5,000 feet and follow each other until near the target before releasing their bombs and climbing steeply immediately afterwards. Targets are struck from all directions almost simultaneously. After releasing their bombs, the planes employ their machine guns against ground installations.

(4) Heavy bombers.—These operate in multiples of nine, divided into subflights of three. Generally, station-keeping is good, although outside flights lose distance on turns. Sometimes the formation commander is in one of the extreme outside planes.

In approaching a target, twin-engined bombers usually have made a long straight run in close formation. Despite heavy losses from fighter or antiaircraft opposition, they have been persistent in attacks.

Type 96 twin-engined heavy bombers used 500 to 1,000-pound bombs in high-level attacks on United States ships in the Netherlands East Indies area. Each plane dropped one and frequently two bombs on each run.

(5) Medium bombers.—These bombers, which fly at high altitudes, move in a V formation, each plane being separated by the width of two aircraft. Bombs are released at altitudes of 8,000 to 12,000 feet. High-altitude attacks are well synchronized with those of dive bombers.

(6) Bomb delivery.—In the Philippines, bombing attacks usually were made by nine planes in a V of V's formation with No. 2 and No. 3 V's 50 to 100 feet above the leading V. When the planes were within 7 to 10 miles of the bomb-release line, they changed to a slightly staggered formation of 1 V. Because of air superiority, the Japanese usually tested the wind drift with a parachute dropped from an observation plane, and made two or three practice runs before the actual bombing. On the bombing run the leader rocked his plane just before reaching the point of bomb release, and all planes usually released their bombs simultaneously. The bombers were believed to be equipped with a mechanical device which opened the bomb racks at regularly-spaced intervals. The course of flight was changed immediately after delivery of bombs.

Japanese bombers began bombing Corregidor at a height of about 17,000 feet, but accurate antiaircraft fire forced them to a height of 27,000 feet.

(7) Use of lights.—In several instances, Japanese bomber formations have been observed to turn on lights during the approach and to turn them off at the bomb-release point. Why this was done has not been determined.

c. Destruction of Fallen Planes

The Japanese apparently seek to destroy completely any of their planes which have been shot down so that United Nations' experts will not be able to study construction details. Australian pilots at Port Moresby report that in each raiding formation the Japanese apparently detail one plane to dive-bomb and destroy planes which have been forced down. On one occasion a fallen plane was blasted with incendiary bombs.

9. PURSUIT

The Japanese use spectacular and unrelenting pursuit tactics against opposition aircraft as well as the ground forces. When the Royal Air Force planes retired from Singapore to Jambi and Palembang in Sumatra, they were followed closely by Japanese air raiders who destroyed or crippled considerable opposing aircraft on the ground. When R.A.F. planes survived an enemy attack on the airdrome at Magwe, Burma, and then retired to Akyab, Burma, the Japanese again pursued relentlessly, destroying the planes on the ground.

10. NIGHT OPERATIONS

Thus far, Japanese night operations in the air have been negligible. The Japanese have done some bombing on moonlight nights and an occasional report has mentioned night-fighter interceptions. Currently, the enemy air force is to all purposes effective only in daylight, although it is believed that training for night flying has been, or will be, undertaken.

11. DECEPTIONS

(a) In Malaya, Japanese bombers blasted airdromes while accompanying fighters engaged numerically-inferior British fighters. The bombers flew out of sight until the British and Japanese fighters broke off their engagement and then returned to catch the British fighters on the ground refueling.

(b) In several instances Japanese planes flew high over airdromes to draw searchlights and antiaircraft fire, whereupon almost immediately a single fighter came in at low altitude with navigation lights on and wheels down to strafe the airdromes. The strafing plane then climbed fast into the nearest cloud.

(c) A Netherlands East Indies plane flew low to investigate some Japanese launches being towed along the northeast coast by "natives" who were waving a white flag. When the plane appeared close, it was shot down by light antiaircraft concealed under the awnings of some of the boats.

12. AIRCRAFT DISPERSAL

a. General

According to reports of most observers, the Japanese generally are vulnerable in their dispersal of planes on the ground. Reports from the American Volunteer Group in China are unanimous that the Japanese crowd their planes on their main air bases, such as Hanoi, Bangkok, Shieng-mai, and Rangoon. Planes have been observed along the runways of these bases almost wing tip to wing tip, bombers on one side and fighters on the other.

b. In the Philippines

At one field in the vicinity of Manila the Japanese used a unique system of dispersing planes on the ground and protecting airdrome installations. They constructed over 40 landing strips (with hand labor and graders) some distance from the central field. Two or three planes and a minimum number of oil drums and other servicing facilities were allotted to each strip. Some of the strips were located as far as 2 miles apart, and hangers and repair facilities were located a considerable distance from runways at main fields. Such a dispersion permitted large numbers of Japanese fighters to take off easily while opposition bombers were concentrating on two or three planes located on one particular strip.