DESCRIPTION. The Enzian was conceived as a ground to air flak weapon. Its secondary purpose was that an air-to-air missile. Models E-1, E-2, and E-3 were the test and ex-perimental articles. All flight tests were carried out with the E-1. The E-4 was the pro-duction design using an improved rocket motor, designed by Dr. Conrad instead of the Walter bi-liquid used in the earlier designs. As the foregoing is the only major difference in the four models, they will be discussed as one: however, there exists another type, E-5, which being a basically different type will be covered in a separate report to avoid confusion.

The E-4 is a flying wing design of striking similitary of the Me-163. Its total weight is 1,800 kg which includes the weight, 320 kg of the four assisted take-off units. The war heads weight is 500 kg. The airplane is constructed of wood, having an over-all length and span of four meters. It attained its velocity of 300 m/ sec with a main thrust unit delivering 2,000 kilograms initially decrasing to 1,000 kg during the flight. Duration range of 16,000 meters and a horizontal range of 25,000 meters.

The four assisted take off units deliver a combined thrust of 6,000 kilograms for 4 se-conds, giving the missile which attains an end speed of 24 m/sec and an acceleration of 3.6 g from a launching ramp 6.8 meters in length. The assisted take-off units are jettiso-ned after 5 seconds.

Although it was anticipated that E-4 would be used as an air-to-air weapon with slight modification, principally reduced fuel load, all experimental flight testing had been done from ground to air. A standard 88 mm gun carriage was adapted for use as a launching platform by the simple addition of two iron rails 6.8 meters long. A traverse of 360° and a vertical firing arc from 0° to 85° were obtained. Air launching of the device was routine; i.e., dropping free from underneath the parent aircraft flying in the direction of the tar-get.

The speed on leaving the launching rails is 24 m/sec; to aviod the possibility of stall no control is applied until the flying speed has reached approximately 55 m/ sec. For practi-cal purposes an elapsed time of 5 seconds is allowed between the triggering of the laun-ching mechanism and the first control signal. The Enzian, as were practically all German guided missiles, was directed to the target vicinity by radio control. When the target ap-proach was within the range of the homing device, the latter took charge of the missiles final run in. Coincidence or line of sight navigation was used under favorable conditions; however, several methods were accepted for night or reduced visibility use.

AIRFRAME. The Enzian E-4 airframe was a flying wing type having no horizontal stabili-zer and a fixed vertical fin. Control was effected through trailing edge flaps which act to-gether as elevators and differentually as ailerons. The basic dimensions are as follows:

Length: 4 meters.
Span: 4 meters.
Maximum diameter, fuselage (Circular cross section): 0.88 meters.
Root thickness: 20 percent root chord.
Tip thickness: 10 percent root chord.
Wing area: 5 square meters.
Airfoil: NACA symmetrical; no twist.
Dihedral: Zero.
Chord root: 1.25 meters.
Chord tip: 0.98 meters.
Sweepback: 30°.
Weight E-4 complete: 1,800 kg.
Empty (including Warhead): 833 kg.
Warhead: 500 kg.
Motor: 97 kg.
Fuel: 550 kg.
Assisted take-off units: 320 kg.
Airframe, Including Control Gear: 333 kg.

For the purposes of an air-to-air missile the fuel weight was reduced of 150 kg and the assisted take-off units discarded. (See fig. 202.)

The airframe was designed to be built of wood because of current metal short-age, but provisions were made for conversion to metal stampings. The production process was to use hot plate gluing methods for fabricating a pressed or plywood material.

Aerodynamically the E-4 appear normal. Its stability in flight tests was accepted as good. The E-48s design perfomance follows:

Maximum velocity (design): 300 m/sec.
   (Measured Walther motor): 240 m/sec.
End speed launching: 24 m/sec.
Minimum speed for safe control: 55 m/sec.
Vertical range: 16,000 meters.
   (Measured Walther motor): 7,000 meters.
Horizontal range: 25,000 meters.
Turning radius: 500 meters.

PROPULSION UNIT. Although the Walther power plant was originally intended for the Enzian and was used in the test flights, it was entirely unsatisfactory and replaced by the Conrad motor. A brief discussion of which is considered sufficient for the purpose of this report.

The bifuel liquid rocket motor uses Salbei (92% HNO₃ + 8% H₂SO₄) and Visol, the ratio of weights being 1.4 to 1. The total quantity of fuel, 550 kg, is ex-hausted in 72 seconds during which time the thrust is reduced from is initial 2,000 to 1,000 kg at end of burning. As pressure reduction between the air bootle and liquid tanks is through a simple orifice plate, the progressive reduction in the combustion chamber operating pressure is the di-rect result of the air bootle's gradual exhaustion. Equal pressure is applied to both liquids and metering is effected by the resistance of the connecting pipes and not that of the nozzles. The total impulse (108,000 - 110,000 kg sec) corresponds to a mean S.I. of 199; however, Wurster states that the mean propellant consumption 5.5 gm/kg sec rises to 5.6 at start and end of burning operation and that the S.I. is of consequence approxi-mately 182.

Although the mixture, Salbei and Visol, is spontaneously inflammable, the Enzian motor used an electrically ignited powder starter in the combustion chamber to effect ignition. This system had the advantages of smoother ignition and less risk of explosion than spontaneous combustion. A further pre-caution against explosion was taken by starting the salbei feed first by shortening its supply pipes and setting its bursting disks at slight-ly lower pressure than those of the Visol system.

The propulsion unit's arrangement, dictated by C.G. considerations, as follows: (1) Air bootle; (2) visol tank; (3) salbei tank; (4) combustion chamber. The air flask was origi-nally inflated to a pressure of 200 atmos. (See fig. 202.)

The liquids are retained in their tanks by means of bursting disks selected to rupture at 15 atmospheres at entry and 36 atmospheres at exit. All tanks are made of mil steel 2 mm thick and no corrosion treatment, enamel, or protective coating was employed as the only General Staff requirement was that the containers should withstand 6 months stora-ge after being filled with salbei and fuel.

Combustion chamber: 24 kg.
Air bootle: 19 kg.
Spherical tank: 30 kg.
Spherical tank: 24 kg; 97 kg.
Fuel weight: 550 kg.

550

Relative to use of an air pressure fuel feed system versus a turbine-pump system, Wurs-ter states that according German figures the former is lighter up to impulse of 200,000 kg/secs and has the additional important advantage of requiring no time for running up to speed. He cited the Me 163 which requires 4 - 5 seconds to run the turbine up to its operational speed of 30,000 pointing out that such delay is prohibitive for a flak rocket.

INTELLIGENCE AND CONTROL SYSTEMS. Operationally it was expected to use the En-zian in the following manner: Launch it toward and direct it to the target vicinity under radio control using the new German equipment Kogge and either line of sight or radar na-vigation. When the missile's approach to the target came within the operating range of the particular selfseeking head employed the latter would assume control and direct the Enzian to the target's proximity on a modified homing course. The proximity fuze at pre-determined distance activates the warhead which as designed to ensure maximum cover-age and effective damage to the target from 45 meters. (See par. on warhead below.) It is considered pertinent to note here that the Germans were doing extensive research work on the theory of homing courses. Their principal investigations appeared to be ba-sed on compromises lying between a pure chaser or homing course and a straight inter-ception route produced by interjecting self navigation into the intelligence system.

Initial planning provided for the Enzian's use of one of several type homing devices and proximity fuzes currently being developed or combinations of the above. Tests had not progressed beyond operation with the standard German radio control, the 6-meter "Strassburg-Kehl", developed by Telefunken and Strassfurt Rundfunk. The "Kogge" desig-ned by Telefunken to operate on a 24-cm wave length was destined for use in the pro-duction Enzians.

The I.R. device, "Madrid", developed by Kepka of Vienna, an acoustic device developed by Telefunken and Messerschmidt, or an electronic device were projected for use as ho-ming heads. These articles had been laboratory tested by their manufacturers only as separate entities.

Metamorphosis of the internal control system from two axis stabilization involving the use of four gyros to acceptance of one axis stabilization using a Horn gyro having two gym-bal rings is outlined above under experimental testing. Standard Siemens electric servos are used to actuate the control surfaces.

WARHEAD AND FUZING. Three types of warhead of equal weight, 500 kilograms, were projected for the E-4. The type which seemed to have accured the most favor among the Messerschmidt engineers and the local flak officiers was built up of a metal shell or container 1 1/2 mm thick. The shell was lined with cylindrical pellets cast of mild steel 20 by 30 mm containing an incendiary core! The explosive cast into the resulting cavity contained a booster charge and fuze in its forward end on the longitudinal axis.

Tests of the above type warhead showed that it could be expected to put 1.5 pellets in an area of 1 square meter at a range of 65 meters.

The second type of warhead incorporated 550 small rockets driven by gun- powder (see sketch below) which had been developed by on of the SS laboratories and were to be used as part of the armament of the Me 262. The rockets were mounted in the warhead to fire forward in a 30° cone from a maximum range of 300 meters; their effective range, however, was 550 meters and at that range each rocket was considered capable of des-troying a bomber.

The third type warhead was straight explosive dependet only on concussion to destroy the target.

Both proximity and self-destruction fuzes were provided. The proximity fuzes were pro-jected on the I.R., Electronic, and Acoustic principals; however, the latter had essenti-ally been dropped by the designers as the maximum range at which the actuating impulse was of sufficient magnitude was too small to derive most effective results from the war-head.

AUXILIARY EQUIPMENT. Four powder jets assisted take-off units delivering a total of 6,000 kilograms thrust for 4 seconds are used to launch the Enzian. The JATO's produced by Rheinmetal-Borsing weigh 80 pounds each. They are attached by explosive bolts which release the cases by firing at the end of burning. Small wings fitted to the JATO's assist in the jettisoning.