The project of the single long-range jet twin-engine reconnaissance aircraft Ar 234A was completed at the end of 1941 (the initial designation of the project was Ar E.370). The RLM technical assignment did not provide for a group launch of these aircraft, therefore, for the convenience of placing fuel and reducing the weight of the machine, the designers of the company abandoned the use of a normal chassis. Instead, a retractable ski was installed under the fuselage, and small supports were provided to ensure stability during landing under the engine nacelles. For take-off, the aircraft was mounted on a dumped launch cart, landing was carried out on a ventral ski.
The first eight prototypes of this series were prototypes (Ar 234V1 - Ar 234V8). The aircraft was first flown into the air by test pilot Captain Zelle on June 15, 1943, later the aircraft was lost. The second Ar 234V2 took off on July 27, 1943, but crashed during further tests. The third aircraft, Ar 234V3, was used to practice takeoff with additional HWK 501 launch boosters, the pressurized cockpit was equipped with a catapult cross, and the aircraft was severely damaged during testing. The fourth and fifth aircraft were in reserve. On the first four copies, the Jumo 004A turbojet engine with a thrust of 840 kgf was installed, the fifth car had Jumo 004B-0 engines with the same thrust, but lighter by 100 kg.
On the sixth and eighth machines, 4 turbojet engines BMW 003A with a thrust of 800 kgf were installed, which were tested for use on machines of the C series. On the sixth machine, the engines were located in separate nacelles, on the eighth - in paired nacelles.
The first flight of the sixth aircraft took place on April 8, 1944, later it passed
military trials at the front. The seventh car, which took off for the first time on July 10, 1944, Main technical characteristics of Ag 234A: crew - one person, takeoff weight - 7750 kg, [actual ceiling - 11,700 m, maximum speed at an altitude of 6,000 m - 765 km / h, range -1940 km. Dimensions: aircraft length - 12, 64 m, height - 4, 3 and, wingspan - 14.41 m. Small arms were not installed, in the rear of the fuselage there were compartments for photographic equipment and a brake parachute. In connection with the decision to build machines of the B series, further work on the A series was stopped.
Series B (prototype Ag 234V9) - the design of the aircraft of this series began in December 1942, i.e. even before the start of flight tests of series A machines, a change was made to the technical task: the aircraft was supposed to be multipurpose and take off from any airfield, including in a group. Therefore, instead of a launch cart and a ski, the designers provided for a normal tricycle chassis, which was used in all subsequent series, two Jumo 004B-2 engines were used as a power plant: Ag 234V-1 - a single-seat reconnaissance aircraft with photographic equipment, small arms were not installed, takeoff weight - 9200 kg, maximum speed - 780 km / h, range - 1950 km, service ceiling - 11,500 m.
A fighter version of this machine was also developed without photographic equipment, and two fixed MG 151 cannons were installed under the fuselage in special fairings.
Ag 234V-2 - the first single-seat serial jet bomber. Armament - two fixed MG 151 cannons firing parallel to the fuselage axis backwards, with 250 rounds of ammunition per barrel. The bomb load could be taken in three versions: one 1000 kg bomb under the fuselage, 2 bombs 500 kg each under the engine nacelles, one 500 kg bomb under the fuselage and two 250 kg bombs under the engine nacelles.
It became the first production aircraft with fixed weapons for firing backwards. This was caused by the appearance in the last years of the war of high-speed, but low-maneuverable jet fighters, in connection with which the line of pursuit in aerial combat was approaching a direct one and the most likely for the fighter was a bomber attack from the tail.
Aiming during firing was carried out through the PV-1B periscope sight, installed in the upper part of the pilot's cabin. The eyepiece of the sight was in front of the pilot's eyes, and the upper part with two lenses (front and rear) protruded beyond the dimensions of the lantern. To prevent icing, there were heaters under the protective glasses of the lenses. The front sight lens was used for dive bombing; the aiming direction (forward or backward) was switched by corresponding rearrangement of the sight's optical prism.
For aiming during bombing from horizontal flight, an automated synchronous bomber sight Lotfe-7k was used, into which data on the flight altitude and aircraft speed were entered. In addition, before departure, data on the speed and direction of the wind, as well as the ballistic coefficient of the bomb, were manually entered into the sight.
The sight was linked to the autopilot. When approaching the target, the pilot turned on the autopilot and turned the sight, directing the vertical axis of the reticle to the target. The turn of the sight was transmitted to the autopilot, and the plane lay down on a combat course. After that, the pilot turned the tracking prism of the sight, throwing the sighting beam forward and directing the crosshair of the sight reticle to the target, and turned on the synchronous mechanism. The synchronous mechanism turned the sighting beam (sight prism) back with an angular velocity equal to the angular velocity of the aircraft relative to the target, due to which the crosshairs of the grid continued to cover the target until the bombs were dropped. The sight was also associated with the ASK-234 electric release device, so the bomb release (salvo or single) was automatic when the sighting beam of the sight made up the required aiming angle with the vertical.
The aircraft cabin was heated with air taken from the power plants. On the day of entering the cockpit, on the left side of the fuselage there was a retractable ladder, steps and handles. The cover of the entrance hatch to the cab in emergency cases could be dumped using a special mechanism. The main advantage of the cockpit layout is a good view of the pilot forward, to the sides and downward, since most of the cockpit was sheathed with plexiglass.
To facilitate the takeoff of a heavily loaded machine under the wing, starting boosters with a thrust of 500 kgf each could be suspended from the outer sides of the engines, which almost halved the takeoff run.
The fuel was placed in two flexible tanks: the front with a capacity of 1800 liters and the rear with a capacity of 2000 liters. For each engine, the Ag 234 and Pi 103 coupling test provided the ability to supply fuel from any tank using cross feed valves.
If necessary, two outboard tanks of 300 liters each could be installed, which were suspended under the engines. In flight, fuel was pumped from the left outboard tank to the rear main tank, and from the right outboard tank to the front main tank.
In total, 210 B-series aircraft were built by the end of the war, and they were used for the reconnaissance "Sonderkommando" "Hecht" and "Sperling" (Ag 234V-1) and the bomber squadron KG 76 (Ag 234V-2). It was supposed to use the Ag 234V as a towing vehicle for the Fi 103 cruise missile, which was equipped with a drop two-wheeled chassis and a tug mount, such tests were carried out in Rechlin.
Series C (prototype Ag 234V19) - bomber, could simultaneously carry up to 1500 kg of bombs, to achieve higher speeds, instead of two Jumo 004B-2 turbojet engines, four BMW 003A turbojet engines were installed, doubled under each wing console. Overall dimensions of the machines of this series are analog-2 ™ (similar to series B. Ag 234S-1) - single-seat reconnaissance aircraft, armament - four stationary MG 151 cannons (two in the forward fuselage for firing forward and two in the rear fuselage, directed backward), takeoff weight - 9900 kg, maximum speed - 870 km / h, range - 1475 km, service ceiling - 11 530 m;
Ag 234S-2 - single-seat bomber, similar to the previous version, take-off weight - 10 100 kg, maximum speed - 895 km / h, range - 1600 km, service ceiling - 11 530 m. Ag 234S-3 - single bomber and night fighter with four MG 151 cannons (in the fighter version, two guns were located in the nose of the fuselage, and two in fairings under the fuselage, trunks forward), takeoff weight - 11 555 kg, maximum speed - 892 km / h, range - 1230 km, practical ceiling - 11 530 m, a FuG 218 "Neptun" radar was to be installed in the nose of the fuselage.
Ag 234S-4 - single-seat reconnaissance aircraft with BMW 003C engines, armament - four MG 151 cannons (two in the nose of the fuselage, two in fairings under the fuselage for firing backwards - with the barrels to the tail), takeoff weight - 9Y0 kg, maximum speed - 880 km / h, practical ceiling - 11 530 m.
Ag 234S-5 is a two-seater bomber with BMW 003S engines.
Ag 234S-6 is a single-seat reconnaissance aircraft based on the previous version.
Ag 234S-7 is a two-seater night fighter equipped with four HeS 011A engines with a thrust of 1350 kgf and a FuG 245 "Bremen" radar in the forward fuselage, armament - two MK 108 cannons of 30 mm caliber and two MG 151 cannons, takeoff weight - 11555 kg …
Ag 234S-8 is a single-seat bomber with two Jumo 004D engines with a thrust of 1050 kgf each, take-off weight - 9800 kg, maximum speed - 755 km / h.
In total, by the end of the war, 10 experimental vehicles and 14 serial ones were built from this series.
The Ag 234S was also tested as a towing vehicle for the Hs 294 missile, in addition to this, the method of launching the Fi 103 cruise missile from the back of the Ag 234S was worked out, for which MG 151 was used, takeoff weight - 11,700 kg, maximum speed - 850 km / h, range - 1125 km
