August 2nd 1944 saw Juvincourt aero- drome bustle with unusual activity. This was the day on which the Luftwaffe’s newest jet aircraft – the Arado 234 – would make its premier operational sortie. The machine sported the sleek, streamlined silhouette of a high-wing monoplane, with two engine nacelles suspended under wings.
It was the engines that aroused so much interest among those present at the airfield. Most of them had never before seen aviation engines devoid of propellers. Another extraordinary feature of the design was its undercarriage – the aircraft was resting on a tricycle trolley! A closer look revealed a sizable, retractable skid installed under the fuselage and two smaller, stabilizing skids mounted under the engine nacelles.
Several minutes later, the Arado Ar 234 V7 (WNr. 130 007, coded T9+MH), with Lt. Erich Sommer at the controls, was towed to the end of the east-west runway. Sommer re-checked his instruments and started the engines, then released the brakes and pushed the throttle levers. The ground crew watched with awe as spurts of red-hot air burst from the engine nozzles with a distinctive whizz. Meanwhile, the aircraft began to roll down the runway. After the first 200 meters the pilot started the auxiliary rocket engines, which promptly spat out billows of white smoke.
“It looks like a flying Nebelwerfer1 battery!” – commented Ofw. Nowitzki. He was a veteran of the eastern front and had had ample opportunity to watch rocket artilleries in action.
The aircraft accelerated rapidly. It appeared to suddenly lose weight and glide like a feather. Sommer jettisoned the trolley and with the Arado smoking profusely from its rocket engines, left the ground. After about 20 seconds the rocket booster units had exhausted their fuel and were extinguished. Immediately, Sommer pressed the release button and both rocket units fell away from the wings, automatically deploying small parachutes. They drifted off towards the edge of the airfield.
The pilot held the climb rate at 13 meters per second, whilst the speed indicator showed 410 kph. Since the aircraft had taken off in a westerly direction, there was no need to alter course, and after a few slight corrections the Arado was headed straight towards its target. Climbing constantly, it soon reached layers of thinner air, which allowed it to further increase its speed. Barely 20 minutes had passed before the machine topped 10,500 meters. Far below, the ground war continued. Sommer kept looking over his shoulder to make sure that his aircraft wasn’t pulling contrails, which would betray his presence to enemy interceptors. However, the sky behind him was clear. High above the Cotentin Peninsula, in the vicinity of Cherbourg, he turned east, dropping some 500 meters and speeding up to 740 kph. After a while he pulled out of the shallow dive and leveled out, getting ready for a photographic session. The lenses’ covers slid back and, as he pressed the shutter release button, the two cameras went to work. They took one set of pictures every 11 seconds, imaging a swathe of land almost ten kilometers wide across the direction of flight.
Weather conditions were perfect, a clear summer sky offering almost unlimited visibility. From such an altitude it was hard to perceive any evidence of the ruthless battles taking place on the ground. Sommer didn’t notice any interception attempts. He was too busy directing his aircraft along a route that would cover the greatest possible area, in order to photograph it with the modest reserve of films in both cameras. His first pass over the coast and the artificial harbour in the area of Asnelles-sur-Mer took ten minutes. Then Sommer turned around and carried out a second pass, photographing a stretch of land ten kilometers away from the beaches, including some airfields around St. Pierre. The third pass, on a parallel course, took him another ten kilometers inland and somewhat to the east of his previous pass. Shortly before he reached the end of the Peninsula, the image counters for both cameras showed zero, indicating that had run out of films.
Sommer continued to the east. His only concern was to deliver the precious images back to base. Carefully scanning the sky around him in search of enemy fighters, he kept descending toward Juvincourt, where he managed to drop the Arado smoothly onto the grass alongside the concrete runway. Before his machine had slowed to a halt, he saw ground personnel running towards him from all directions. As he climbed out of the cockpit, both cameras were extracted from the fuselage through hatches in its spine. The film boxes were secured in a special container and passed to messenger mounted on a motorcycle, who took them to a darkroom to be processed.
During his first flight Sommer gathered more intelligence data than all the other German reconaissance units had managed to collect during the past two months. It took him an hour and a half to photograph nearly the entire Allied beachhead in Normandy. The 380 photographs taken by the Arado cameras proved a sensation. By that time the Allies had transported to France over 1.5 million soldiers, nearly as many tons of supplies and close to a million vehicles. The initial analysis of the photographs, conducted by a team of twelve specialists, took two days. Further work on them continued for several weeks. As Sommer recalled: After my first operational mission many high-ranking officers of the Wehrmacht came to Juvincourt to have a look at our new machine. Nevertheless, since the entire project was classified top secret, they were simply refused entry to the hangar with the Arado.
Design and development of the Arado Ar 234A variant In the latter part of the ‘thirties Germany became the birthplace of the first jet engines reliable enough to be used as a means of propulsion for aircraft. The RLM (Reichsluftfahrtministerium – Reich Air Ministry) became interested in the potential of this new propulsion system and invited tenders for the design of a jet powered high-speed fighter and reconnaissance aircraft. The bid for the fighter design was won by the Messerschmitt factory and resulted in the creation of the Messerschmitt Me 262 Schwalbe. The task of creating a high-altitude jet-powered reconnaissance machine was, in turn, bestowed upon the Arado company.
The Arado Flugzeugwerke G.m.b.H. was created in 1925 from Flugzeugbau Friedrichshafen G.m.b.H. at Warnemünde, a company that had manufactured aircraft since 1917. Initially, the new company specialized in trainers, but by the end of the ‘twenties it had also begun to work on military projects. When the National Socialist Party seized power in Germany, the company received several lucrative contracts. It took upon producing the Arado Ar 64 and Ar 65 fighters, as well as Ar 66 trainers. The chief designer of the company at that time was Dipl.-lng. Walter Blume, who replaced Walter Rethel. Blume was born on 10th October 1896 in Hirschberg (presently Jelenia Góra in Poland) at the foot of the Riesengebirge (now Karkonosze) mountain range. When the Great War broke out, he volunteered for military service, quickly attaining the rank of Oberjäger. He was subsequently transferred to the air force and, on 30th March 1916, gained his pilot’s license. In June 1916 he was posted to join Feldfliegerabteilung No 65. At the beginning of 1917 he was promoted to the rank of Leutnant and served with Jagdstaffel 26. The deputy CO of the squadron at that time was the future Reichsmarschall, Hermann Göring. On 10th May 1917, Walter Blume achieved his first aerial victory. After several more, on 14th August 1917, he was awarded the Iron Cross First Class. On 2nd October 1918 he received the highly coveted Order Pour le Mérite. He scored his last victory on 28th October 1918.
After the war he studied engineering, graduating in the autumn of 1922. Thanks to his acquaintance with Göring he was given a job at Arado. (After the Second World War he formed his own company and worked with the Focke-Wulf-Werke in Bremen on production of a licensed version of the Italian Piaggio P-149Ds. Later, he was involved in producing the C-160 Transall. He died on 27th May 1964, after a long illness).
Due to its reliance on government subsidies the Arado company was, in effect, directly controlled by the RLM. Hence, besides producing its own aircraft, Arado also manufactured Heinkel, Messerschmitt, Junkers and Focke-Wulf designs under license. The most successful of Arado’s own products was the Ar 96 trainer and its development versions, the Ar 296 and Ar 396, together with a reconnaissance hydroplane design, the Ar 196. By the end of 1944, the Arado factory and its subordinated plants formed a huge military-aviation industrial complex, employing 15,786 workers. A further 16,260 worked for Arado’s exclusive sub-contractors.
The RLM’s order for a high-speed jet reconnaissance aircraft was issued in the autumn of 1940 and inspired little interest in Dr. Walter Blume. Blume had no experience with jet propulsion and was somewhat skeptical about it. Moreover, Luftwaffe officials had informed him that no more than 50 serial machines of this new type would be produced. Such a small number was of little benefit to his company.
Although nominally head of the design team, Blume delegated the entire project to Rüdiger Kosin, chief of the company’s aerodynamics department. His team included Hans Rebeski, Hugo Wenzel, Franz Meyer and Walter Lehmann. Since they were simultaneously involved in developing the Ar 232 transport and Ar 240 ‘destroyer’ aircraft, it took almost a year to complete the initial studies. In October 1941, they presented a project designated E.370/IV, for a single-seat, cantilever high-wing monoplane of monocoque construction, with straight wings and single-fin tail unit. The aircraft was to be propelled by two BMW P 3302 jet engines located in underwing nacelles. The fuselage, of cylindrical cross-section, was to house a pressurized cockpit, three fuel tanks and two Rb 50/30 (or Rb 70/30) photographic cameras. Defensive armament was to consist of one fixed 13 mm MG 131 machine gun mounted in the aft fuselage. Total fuel capacity was 4000 liters.
The design of the aircraft’s landing gear changed several times. The team worked on several solutions: a single retractable fuselage skid; a bogie of small auxiliary wheels mounted underneath the fuselage (as in the Ar 232 transport) with skids beneath the engine nacelles; and a tricycle take-off trolley combined with retractable landing skids mounted beneath the fuselage and engine nacelles. Eventually, the last variant was chosen. The rather basic landing gear had its advantages – it constituted only 3% of the aircraft’s take-off weight.
In late October 1941, Obstlt. Theodor Rowehl, the commander of Aufklärungsgruppe Oberkommando der Luftwaffe (the German Air Force HQ reconnaissance unit) joined a meeting held by the Arado engineering team. His unit, hitherto flying twin-engined Junkers Ju 86Rs as high-altitude reconnaissance machines, was to be the main recipient of the new design. Rowehl, well aware that the Ju 86R’s weakness was its lack of speed, was keenly interested in the new aircraft and expressed a favorable opinion about the project. His views were instrumental in persuading the Technisches Amt of the Reich Air Ministry to approve the E.370/IV for production, on 24th October 1941.
On 17th November 1941, Ernst Udet, the Generalluftzeugmeister and head of the RLM’s T‑Amt, committed suicide. It had seemed likely that the Arado project would be shelved, but events were to take another course. On 4th February 1941, Udet’s successor, Generalfeldmarschall Erhard Milch visited the Arado plant in Brandenburg and was shown the E.370/IV project. Milch was greatly impressed by it and ordered a full-scale wooden mock-up to be built, designated 8-234 by the RLM. In April the RLM ordered six prototypes, designated Arado Ar 234. The RLM requested that the new design have a range of 2150 km, a maximum speed of over 770 kph at 6000 meters and a service ceiling of up to 11,000 meters.
Throughout 1942 the Ar 234 was submitted to many tests in the aerodynamic tunnel of the Arado plant. They proved very satisfactory. However, the BMW 109003 engines, which were to become the aircraft’s powerplants, were still under-developed. As they grew in diameter, new, wider engine nacelles became necessary, which affected the aerodynamics of the aircraft. Even worse, the BMW engines’ thrust turned out to be lower than predicted. Hence, the design team was left with little option but look for an alternative powerplant for their aircraft. They decided to employ the Junkers Jumo 109004 turbojet.
Since this engine was even bigger than the BMW 109003, the aircraft’s wings had to be re-designed. Wing area was slightly increased and the flaps and ailerons re-shaped; the wings’ leading and trailing edges were also re-worked. Fuel load was split among three fuselage cells with a total capacity of 3700 liters. Defensive armament was deleted; only a 15 mm armored plate mounted behind the pilot’s headrest remained as passive protection.
On 28th December 1942 the T-Amt ordered an additional 14 prototypes, increasing the overall number to 20. However, the RLM’s representatives were dissatisfied with the aircraft’s unconventional undercarriage system, consisting of a take-off trolley and landing skids. In order to meet their demands, the Arado design bureau prepared another Ar 234 variant in January 1943, designated E.371. It was equipped with a classic tricycle landing gear with front wheel. The fuselage had to be widened by 21 cm in order to accommodate the retractable undercarriage. Wheel well bays were installed in place of the 775-liter central fuel tank. The project was approved by the T-Amt and on 9th February 1943 it ordered two prototypes. The new variant, designated Ar 234B, was to be a bomber version of the basic reconnaissance design.
As a matter of fact, a bomber version of the Arado Ar 234 had been discussed long before the first prototype had flown. On 9th July 1943, at a conference held by Erhard Milch in the Reich Air Ministry, the Inspector of the Bomber Force, Obst. Dietrich Peltz talked about the high losses sustained by his subordinates at the hands of the ever more powerful Allied fighter arm. He concluded that the only solution to this problem would be the re-arming of the Luftwaffe with jet bombers:
Milch (jokingly): ‘So, we have a request for a jet bomber. A modest one, typical of Peltz. He expressed his little wish to have several hundreds of them, and that by the end of November!’
Pasewaldt (on Milch’s staff): ‘We have taken some steps already, increasing the initial order of 20 Ar 234, a type of aircraft which has been of considerable interest to us for some time, up to 100 machines, and that of experimental variants only. However, the design has not been test-flown so far. When can we expect that?’
Friever (the Arado company representative): ‘Within a week.’
Milch: ‘The Ar 234?’
Pasewaldt: ‘The Ar 234 looks very promising. We expect it to fulfill all our expectations. It has to be taken into account, however, that the Arado 234 was designed to be a reconnaissance aircraft. The question of re-designing it into a bomber has recently been investigated. The Arado 234 has much greater potential for this than the Me 262, which should be unconditionally restricted to the fighter role.’
In the latter part of February 1943 the sixth and seventh specimens of the Jumo 004A-0 engine were delivered to the Arado company. In the spring of the same year the Brandenburg plant assembled a further four prototypes. Tests of the delivered Jumo 004 showed that the expected thrust of 850 kG (8.3 kN) was unattainable. The demand for more thrust necessitated the use of auxiliary external Rauchgerät Walter HWK 109 500 rocket boosters, which provided an additional 500 kG (4,6 kN) of thrust for 30 seconds. Once their fuel was consumed, the boosters were parachuted to the ground. Another alternative proposed by Arado was the installation of four BMW 003A-0 engines, instead of two Jumo 004 engines. Although the BMW engine’s thrust was smaller by 50 kG, it was 250 kg lighter than its Junkers counterpart. Nevertheless, this project had to be shelved until the BMW powerplants were reliable enough to be mass-produced.
On Sunday 18th July 1943 the dismantled prototype Arado Ar 234 V1 (WNr. 130 001, coded TG+KB) was delivered to Rheine aerodrome, where it was re-assembled the following day. By 21st July 1943, the Junkers Jumo 004A-0 engines had been installed and taxiing tests were conducted with the aircraft resting on its take-off trolley. On 26th July 1943, during another ground test, a loose cowling caused the port engine to catch fire as it revved up to 3000 rpm. The Arado plant quickly overhauled the damaged engine and, on Friday 30th July 1943, at 20:10 hrs, the Ar 234 V1 took to the air for the first time. Arado’s chief test pilot, Flugkapitän Heinz Selle, flew the machine. Before the maiden flight took place the aircraft’s take-off weight had been reduced to 5695 kg (6330 kg with take-off trolley), so there was no need to employ the Walter HWK rocket boosters. After a 750-meter take-off run the Ar 234 V1 finally got off the ground. At 500 meters the pilot released the trolley successfully – only for it to smash into the ground due to a faulty parachute deployment. The first flight took 14 minutes. Selle sped the machine up to 650 kph and recorded:
The engines worked faultlessly. They were surprisingly quiet in comparison to piston engines. Their noise was barely audible in the cockpit and the vibration of the airframe minimal.
The only problem encountered during the flight concerned the auxiliary landing skids mounted under the engine nacelles. Selle recalled:
The retraction mechanism of the main landing skid worked as intended. However, neither of the two stabilizing skids snapped up into the locked position. During the flight they constantly “pumped” up and down. When I turned or climbed, they extended fully down and jammed in that position.