1. INTRODUCTION

The original German doctrine regarding the employment of German Air Force flak artillery in the field has steadily been undergoing modification. German manuals formerly described the responsibility of flak in the field as primarily, and almost exclusively, antiaircraft defense; the engagement of ground targets was regarded as secondary, and only to be undertaken in an emergency. Although the older manuals admitted the possibility of using light flak to reinforce the fire of heavy infantry weapons, and of using heavy flak to supplement antitank and other artillery, such employment was described as exceptional. There was nothing to suggest, for example, the now extensive use of the 88-mm antiaircraft gun in an antitank role.

The transition from the defensive doctrine of the earlier manuals to the more aggressive modern conception seems to date from the introduction of the Flak Corps—units of which first appeared during the Battle of France. The Flak Corps was created to perform the tasks described in the following enemy notes.

As these notes show, flak in the field is now intended to serve as a powerful and highly mobile striking force. The emphasis laid on its employment in the ground role, and in an offensive capacity in conjunction with spearhead formations, is most important. Experience has verified that these principles are actively practiced in the field.

2. HEAVY FLAK

a. General

In operations with the field army, the 88-mm gun, as a result of its great mobility, has become almost the universal weapon of heavy flak. Larger calibers are usually encountered only in areas where the defense is static.

The heavy flak battery consists either of four or six guns (usually 88's), with two light guns (20-mm) for close protection. Six-gun batteries are becoming increasingly common. In theory the heavy battery consists of two platoons, but in practice it is rarely divided in this manner. All the guns are generally fitted with shields, to protect the detachments against small-arms fire, and with two sights—a telescopic sight for the direct engagement of ground targets, and a panoramic sight for indirect laying. In the interests of mobility, the fire-control equipment is often left behind. In addition to time-fuze high-explosive ammunition, armor-piercing and percussion-fuze high-explosive ammunition is normally carried. To avoid the muzzle flashes which, at night, readily give away the gun positions, the Germans now make widespread use of a flashless propellant.

The 88-mm gun can be put into action in about 2 minutes. If necessary, it can be fired from its mount, but against ground targets only.¹ Since the normal mount is conspicuous because of its height, the gun is extremely vulnerable to artillery fire. Whenever possible, therefore, the gun is dug in so that only the barrel appears over the top of the emplacement. (Actually, the time factor and the frequent moves do not always permit the Germans to devise effective concealment.) Realizing that destruction of hostile observation posts constitutes an indirect method of protecting their heavy flak guns, the Germans try to accomplish this at every opportunity.

The 88-mm guns can open fire on armored vehicles at 2,500 yards with fair prospect of success, but are most effective at ranges of about 1,000 to 1,500 yards. They may fire at ranges of as much as 4,000 yards, if other and more inviting targets are not available. With the aid of a forward observation post, 88's sometimes engage such targets as troop concentrations at ranges of as much as 6,000 yards.² The following are examples of the penetration performance with the 88-mm Flak 36, the most common model of this gun:

Range (yards)	Thickness of armor
	30° angle of impact	Perpendicular (no angle of impact)
500	110 mm (4.33 in)	129 mm (5.07 in).
1,000	101 mm (3.97 in)	119 mm (4.68 in).
1,500	92 mm (3.62 in)	110 mm (4.33 in).
2,000	84 mm (3.30 in)	100 mm (3.93 in).

It is estimated that the following figures are correct for the 88-mm Flak 41:

Range (yards)	Thickness of armor
	30° angle of impact	Perpendicular (no angle of impact)
500	150 mm (5.91 in)	175 mm (6.89 in).
1,000	140 mm (5.51 in)	164 mm (6.46 in).
1,500	130 mm (5.12 in)	153 mm (6.02 in).
2,000	121 mm (4.76 in)	142 mm (5.59 in).

b. Employment in Rear Areas

In rear areas heavy flak has the normal task of providing antiaircraft protection for ports, airfields, dumps, headquarters, and points of importance on lines of communication. Predictors and/or auxiliary predictors are employed, and mobile radio-location equipment may also be allotted. Although flak units in rear areas primarily have the task of providing antiaircraft protection, even these units are normally provided with armor-piercing and percussion-fuze high-explosive ammunition, and therefore can operate against any hostile troops or armored vehicles which may break through. The heavy flak's degree of preparedness to meet such attacks naturally depends on the distance between the guns and the front.

c. Employment in Forward Areas

It is in the employment of heavy flak batteries attached to the Army, for operations in forward areas, that current German methods depart most noticeably from the doctrine expressed in earlier manuals. Formerly, German doctrine outlined a primary antiaircraft role, a secondary antitank role, and, under exceptional circumstances, employment in a field-artillery role. It may be said that the antitank role now has assumed virtual priority, for experience has shown that the 88-mm gun has become an indispensable complement to the German Army's antitank artillery. A certain proportion of heavy batteries in forward areas is still deployed in an antiaircraft role, chiefly to protect forward airfields, and during periods of inactivity or preparation the antiaircraft role still predominates. For example, an assembly prior to an attack will usually be protected by heavy guns, and under these conditions the ground role is assumed only in the event that the Germans are subjected to a surprise attack. However, once battle is joined, whether in attack or defense (and especially when armored forces are involved), the heavy flak guns are usually employed against ground targets only, and the antiaircraft role becomes the exception. If necessary, even guns originally deployed to give antiaircraft protection to forward airfields are sometimes pressed into service as antitank weapons.

The employment of heavy flak batteries naturally varies considerably, depending on the terrain and the nature of the fighting. In open country the 88-mm gun's long range gives it a distinct advantage as an antitank weapon. In North Africa, where so often there was no well-defined "line," heavy flak batteries often served as the nucleus of defensive "hedgehogs." In an advance the primary function of the batteries usually has been to provide antitank protection during the movement of German armored vehicles. The 88's have also been known to accompany tanks in an assault-gun role. Although the battery is the normal fire unit, large numbers of 88-mm guns have occasionally been employed under one command when the situation has required that maximum antitank strength be concentrated at a single point.

A striking example of the value of heavy flak in defense is afforded by the final phases of the Tunisian campaign, in which heavy flak units frequently provided the backbone of German resistance to the Allied advance. For this purpose several units were formed into mobile battle groups, a procedure which had been resorted to on previous occasions, and which presumably is dictated by the stress of circumstances. These flak battle groups are purely temporary units, formed for a specific purpose. They consist of a number of platoons, usually with two heavy and three light guns each, and may be employed either alone or in combination with other arms. They are used both in defense and in attack. Since they are mobile striking forces, there is always a possibility that they will be used by the Germans in attempts to repel landings on the European continent. They would afford a means of rapid counterattack in threatened sectors. The employment of these temporary units, which has become increasingly common, demonstrates the flexibility of flak organization in the field and the extent to which the Germans use heavy flak to complement antitank artillery.

The employment of a heavy flak battery is naturally governed by the type of operation that is being undertaken by the Army unit to which it is attached. Although the lessons learned from desert warfare are not necessarily applicable to other theaters, the activity of a heavy flak battery during the early stages of the German counteroffensive in Cyrenaica in May 1942 affords some very good tactical illustrations. During this action the battery accompanied the Army unit to which it was attached, and provided protection both against air attacks and tank attacks. The ground role predominated. Not only were tank engagements fought by day, but at night the battery was deployed in an antitank role to protect its "parent" Army unit. The battery was continually on the move during the day. More than once it detached some of its guns to strengthen another Army unit, and at other times it, in turn, was given added strength. When opposition was expected, the battery took up an antitank siting, generally on high ground and facing the probable line of attack. The choice of this position was not hard-and-fast. The battery moved to a different position when reconnaissance had established the location and course of the hostile tanks. When in position, the battery often had to site its guns so that they faced in two directions, because of uncertainty as to the exact line of attack.

3. LIGHT FLAK

a. General

Light flak units operating in the field are generally equipped with 20-mm guns (single- or four-barreled), sometimes with 37-mm (1.45 in.) guns, and once in a great while with 50-mm (1.97 in.) guns. A light battery normally consists of four platoons of 20-mm guns, or three platoons of the larger caliber light guns, with three guns to each platoon.

Light flak guns are especially useful in combatting surprise attacks, because of the rapidity with which these pieces can be put into action. The 20-mm Flak 30, for example, can be put into action in about half a minute, and in extreme emergencies all light flak guns can be fired (although with a limited traverse) from their mounts. In addition, it is known that self-propelled models of the 20-mm and 37-mm calibers exist and can engage both air and ground targets. Like the heavy guns, the light guns in the field are usually fitted with shields for protection against small-arms fire. They are also fitted with flak sights and/or telescopic or linear sights, and carry armor-piercing ammunition in addition to percussion-fuze high-explosive ammunition. Light flak guns may engage ground targets, especially "soft-skinned" vehicles, at ranges of as much as 800 yards, but are most effective at ranges up to about 300 yards. The following are examples of the penetration performance of the 20-mm Flak 30 firing armor-piercing projectiles:

Range (yards)	Thickness of armor
	30° angle of impact	Perpendicular
100	31 mm (1.22 in)	48 mm (1.89 in).
200	29 mm (1.14 in)	44 mm (1.73 in).
300	27 mm (1.06 in)	41 mm (1.61 in).
400	25 mm (0.98 in)	38 mm (1.50 in).

b. Employment in Rear Areas

In rear areas light flak batteries have the normal task of giving antiaircraft protection to such vital points as airfields, bridges, railroad stations and junctions, headquarters, and depots. For this purpose batteries are generally deployed as a whole, with the guns sited by platoons. Although the antiaircraft role predominates, these batteries constitute an important element in the ground defense plan for the vital rear points they are protecting, and are prepared to engage any armored or other forces which may succeed in penetrating to that depth.

c. Employment in Forward Areas

Light batteries attached to Army units in forward areas may also operate as a whole, but platoons are usually detached to perform special tasks.

On the march, platoons are generally spaced at intervals along the column, or are sited at particularly vulnerable points along the route—such as bridges, defiles, or crossroads—and subsequently "leapfrog" forward. Their principal task is to protect the column against attack by low-flying aircraft; their secondary task is to engage ground forces.

In battle light flak units afford protection for headquarters, field artillery concentrations, infantry concentrations, engineer units, motor parks, and so on. Also, it is sometimes considered necessary to assign a light platoon (three guns) to a heavy flak battery engaged in antitank work—presumably because, under certain circumstances, the two light guns belonging to the two batteries do not afford enough protection. In all these tasks the antiaircraft role predominates, but engagement of personnel and armored vehicles is also regarded as highly important and often takes place. Experience has shown that during tank attacks, light guns, as well as heavy guns, have ignored air targets and have concentrated on hostile armored vehicles, leaving German ground units to defend themselves against air attack by means of rifle and light machine-gun fire. (As previous issues of the Intelligence Bulletin have explained, German Army training stresses the importance of small-arms fire in defense against low-flying aircraft.)

It will be seen that whereas heavy flak—which is well suited to combat ground targets, partly because of its penetration performance—is now being given wide tactical employment in a ground role, light flak with the Army still clings pretty much to the principles outlined in German pre-war manuals. Although the capability of light flak in a ground role is always something to take into account, this type of employment seems to be the exception, rather than the rule.

NOTE.—This section has dealt solely with German Air Force flak. There are also (1) Army flak (Heeresflak) units, which include "mixed" battalions (containing both heavy and light batteries) as part of the artillery, and (2) light companies (Fla), which have light guns only, as part of the infantry. These other types are not numerous, however. As a rule, they are GHQ troops, and are attached to army units in much the same way that German Air Force flak units are attached. Recent enemy documents show that an Army flak battalion, consisting of two heavy batteries and one light battery, is now included in the tables of organization of armored and motorized divisions.