German Explosives
HS 298
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V-1
Length Overall: 328 centimeters
Length of Fuselage: 180 centimeters
Span of Wings: 129 centimeters
Span of Horizontal Stabilizer: 53 centimeters
Height of Vertical Rudder: 29 centimeters
Diameter of Fuselage: 39 x 20 centimeters
V-2
Length Overall: 249 centimeters
Length of Fuselage: 191 centimeters
Span of Wings: 127 centimeters
Span of Horizontal Stabilizer: 53 centimeters
Height of Vertical Rudder: 31 centimeters
Diameter of Fuselage: 39 x 25 centimeters
Principal Weights
Launching Weight: 120 kilograms
Weight at Target: 98 kilograms
Weight of Propulsion Unit: 33 kilograms
Weight of Explosive: 48 kilograms
Performance
Average Horizontal Speed: 240 meters per second
Mach. No.: 0.75
Max. Range: 3.5 kilometers at 5,000 meters altitude (approx.)
Min. Range: 0.6 kilometers
Ceiling Above Launching Point: 1.3 kilometers
Max. Elevation for Attacks from Below: 50 degrees
Propulsion Motor
Total Rocket Motor Weight: 27 kilograms
Booster Charge Weight: 5 kilograms
Main Powder Charge: 6 kilograms
Weight (Empty): 16 kilograms
Total Propellant Weight: 11 kilograms
Duration of Burning of Main Rocket: 25 seconds
Duration of Burning of Booster: 5.5 seconds
Thrust of Launch with Booster: 150 seconds
Booster Impulse: 1,200 kilograms per second
In April 1944, production of 2,500 Hs. 298's was ordered by RIM with a peak production rate of 300 airframes per month. In July 1944, the RIM ordered the production of an additional 2,000.
Description: This missile was designed primarily as an air-to-air weapon to be carried on fighter aircraft as well as the bomber types. The fuselage is of the conventional type mounting twin vertical tail surfaces at the ends of the single horizontal tail surface, the horizontal tail surface being mounted high on the fuselage. The arrowhead wing is placed about the center of the fuselage. The nose, like the Hs 117, is symmetrical, the asymmetry on this missile being the vertical plane.
For the propulsion system this missile uses a two-stage powder rocket. Spoiler type of aerodynamic controls is used. This missile used a short length of launching track mounted underneath the parent aircraft.
The following detailed report is written around the Hs 298 V-2, as this model is considered the basic model of the series.
Airframe
Description: The fuselage is a stressed aluminum skin structure. The wing and tail are cast magnesium with an aluminum covering. The cast magnesium wing frame is extremely light in weight and rigid.
Aerodynamic Characteristics/Peculiarities: The missile is controlled in roll and yaw by trailing edge spoilers on the wings. It is controlled in elevation by spoilers on the horizontal stabilizer. Trailing edge spoilers were used because they gave an adequate and simple control as compared to other systems and produced less drag.
The forward part of the fuselage of this missile, like that of the Hs 117, is non-symmetrical; however, in this missile the asymmetry is in the vertical plane. The reason for this change is not known. The after section of the fuselage also has a peculiar shape in that it ends in two tubular shapes, placed one above the other. The top one is the smaller of the two and accommodates either a flare or a light for the purpose of recognition and enabling the pilot to follow it. The lower circular cross section accommodates the powder rocket motor.
Power Plant
Propulsion Motor Data: The power plant is a powder rocket with two combustion chambers exhausting through the same nozzle.
Fuel: The fuels of this motor are dry powder. The booster is a single perforated charge with a round hollow shaped charge having a very slow burning rate. In the hollow cavity of this charge are placed alternate slugs of material, first a slug of powder with a very high burning rate (apparently similar to black powder) followed by a slug of inert material. These slugs are packed one against another throughout the core of the main slow burning powder. This combination presented only few problems, the main one being the sensitivity of the fuel to temperature. For a time it was thought necessary to heat the projectile while still attached to the launching aircraft, but experiments in this direction had not been completed.
Operation: Apparently the powder available for the main charge burned too slowly to use the standard end burning technique, so a complicated procedure was worked out. In order to obtain sufficient area for burning, a conical burning surface is used. To prevent this surface from degenerating to a section of a sphere as the charge burns, the peculiar core construction was devised. This consists of alternate plugs of an inert material and a very rapid burning powder. With the proper geometry of these plugs, the speed of core burning can be maintained which will preserve the original core angle. The chamber pressure is lower during the burning of the main charge than during the boost. It was desired to decrease the throat diameter of the nozzle to compensate for this effect, but this was never achieved.
Intelligence and Control System
Description: The radio receiver and other electrical equipment of this missile was made as similar as possible to that of the Hs 117, the main difference being the arrangements to accommodate the two-wire control that is used for this missile. Since all radio directed missiles are subject to jamming, the Germans, including Wagner's group, have experimented extensively with this two-wire missile control. All Henschel missiles are adaptable to wire control.
It is interesting to note the crude form of air speed measuring device intended to control the throw of the spoilers in the same proportion to the missile speed. This device is mounted on the top of the tail portion. This restriction to the throw of the spoilers is probably done by inserted the spoiler solenoid circuits by means of a resistor on the pivoted, spring returned support of the pear-shaped speed measuring plug.
Power for the electrical system was obtained from a propeller-drive generator. This missile was limited to use against targets with a speed of 140 meters a second or less.
Warhead and Fuze
Warhead: This missile contains a 48kg thin case blast effect charge. It is reported to be placed around the outside of the propulsion unit, which appears necessary from space considerations and is desirable in that the C.G. of the propellant charge can be held nearer to the C.G. of the entire unit. A small amount of insulation protects the explosive from the heat of the propelling charge.
Fuze: The missile was designed for the C-98 "Abstandszunder" high-frequency proximity fuze; however, nearly any of the other proximity fuzes would work. This missile also incorporated a self-destroying fuze which operated at a certain time interval after launching.
Launching Device
This missile uses a rail-type launcher 60 cm in length hung on the carrier aircraft on the under side of the fuselage or wing of either bomb or fighter aircraft.
Next Time: Rockets (Part 5)
Source: German Explosive Ordnance Vol. 1: Bombs, Rockets, Grenades, Mines, Fuzes & Igniters
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