Nazi Germany (1938)
Multi-role Fighter – 12 ~ 18 Built

The Ar 240 was designed as a possible replacement of the Me 110. While initially it seemed to have great potential, problems with handling and mechanical breakdowns proved to be too much for this aircraft. As it would not be accepted for service, only a small number were actually built. While a few were used by the Luftwaffe, their operational usage was limited.

History of Arado

Werft Warnemünde, later known as Arado, was an aircraft manufacturer that was founded during the Great War, in 1917, as a subsidiary of Flugzeugbau Friedrichshafen. In 1921, this company was purchased by an engineer, Heinrich Lübbe, who was more interested in designing and building ships. In 1924, it was once again engaged in development of aircraft designs, mainly intended for foreign markets. For the position of chief designer, Walter Rethel, who previously had worked for Fokker was chosen.

Werft Warnemünde would be renamed in 1925 to Arado Handelsgesellschaft and renamed again in March 1933 to Arado Flugzeugwerke GmbH. At this time, Walter Blume was appointed as the new chief designer. During his supervision, several projects that were later used by the Luftwaffe were built, including the Ar 66 trainer and the Ar 65 and Ar 68 fighter aircraft.

At the start of the Second World War, Arado was mostly engaged in licenced aircraft production for the Luftwaffe. But work on its own aircraft designs was not discarded. The most important of these upcoming designs were the Ar 96 trainer, Ar 196 reconnaissance plane and the Ar 234, which would become the first operational jet bomber in the world. While these proved a huge contribution to the German war efforts, the Ar 240 design proved to be a failure.

Development of the Ar 240

During 1938, the German Ministry of Aviation (Reichsluftfahrtministerium, RLM) was interested in the development of a new multi-purpose twin engine aircraft that would replace the Me 110. Besides Messerschmitt, which began development of the Me-210, the Arado company would also be involved. In early April 1939 or 1938, depending on the source, the Arado company received a contract for the construction of three prototypes of the new multi-purpose plane initially called E-240. The development of this new aircraft was carried out by an Arado team of designers and engineers led by Walther Blume and by Dipl.-Ing. Wilhelm van Nes.

Interestly, possibly for reasons such as good connections with the Nazi Party or Arado’s good reputation as an aircraft manufacturer, even before the completion of the first prototype, an order for 10 additional prototypes was given by the RLM. While these would be built, a number of problems were identified which would prove to be the downfall of the aircraft.

Technical Characteristics

The Arado 240 was designed as a two seater, twin-engined, mid wing monoplane. The fuselage had a monocoque design and stressed-skin. The fuselage was oval-shaped, with the rear part being more round shaped. The rear tail of the Ar 240 consisted of two fins and rudders, but also had dive brakes installed.

The central parts of the wings were rectangular, while the outer part was trapezoidal in shape. The wings were constructed using a two-part spar structure. The Ar 240 used Fowler type flaps, which covered the entire trailing edge. What is interesting is that the Ar 240 flaps were integrated with the ailerons and that this configuration was previously tested on the Ar 198. Another innovation was the use of automatic leading edge slats, but this system was used only on the first few prototypes and abandoned later on. The wings also housed four fuel tanks on each side, which had a total fuel load of 2,300 liters (600 US gallons). The fuel tanks were built using a new self-sealing system that used thinner tank liners, which enabled the aircraft to have a much increased fuel load.

The cockpit was initially positioned directly over the place where the wing root. After the third prototype, the cockpit was moved forward. The cockpit used a back to back seat configuration, with the pilot positioned on the front seat and the radio operator, who was also acting as the rear gunner, being positioned in the rear seat. The Ar 240 cockpit was completely pressurized. The cockpit was directly connected to the fuselage, but was provided with a jettisonable canopy in case of emergency. The well designed glazed canopy provided the pilot and crewman with an excellent all-around view.

The Ar 240 used a conventional retractable landing gear which consisted of two front wheels and one smaller tail wheel. The two front wheels retracted outward into the engine nacelles, while the third wheel retracted into the rear tail fuselage section.

The Ar 240 was tested with a number of different engine types, as the designer had problems in finding an adequate one. The prototype series was powered by Daimler Benz DB 601A and DB 603 A. The later built A series would also be tested with a number of different engines, including the DB 601 A-1 and DB 603, BMW 801 TJ etc..

Different armaments were proposed for the AR 240, including a pair of remotely controlled defence turrets. The control of these turrets was hydraulic and they were equipped with periscope aiming sights. The bomb load would consist of around 1 to 1.8 tons, placed under the fuselage.

Development and Usage of the Ar 240 Prototype Series

Note: Due to differing information depending on the author, the following information was mostly taken from G. Lang. (1996), Arado Ar 240, A Schiffer Military History Book.

The first operational Ar 240 V1 prototype (markings DD+QL), powered by two 1,157 hp DB 601 engines, was completed in early 1940 and was flight tested on the 10th of May the same year. The next flight tests were made on 25th June and 17th July 1940. In May 1941, the engines were replaced with two DB 603 E. More tests were carried out until October 1941, when the prototype was removed from service for unknown reasons. According to M. Griehl, it was destroyed on the 18th April 1941. The test results of the Ar 240 V1 showed that this aircraft had huge problems with the controls and was difficult to fly, a trend which will be inherited on all Ar 240 planes.

The second prototype, V2, is somewhat shrouded in mystery, as the date of its first operational test flight is unknown. A possible date for the first test flight is 15th September 1940. While it is not clear, the V2 prototype probably received the DD+CE markings. Arado test pilots made several flight trials during September 1940. By the end of February 1941, the Ar 240 V2 prototype was relocated to Rechlin for future tests. By May 1941, the V2 prototype received new DB 603 engines. At the same time, it was also fitted with two 7.92 mm (0.311 in) MG 17 and two 20 mm (0.78 in) MG 151/20 cannons. In November 1941, this plane was modified to be used in dive bombing trials. An additional change was the installation of two DB 601 E engines. The final fate of the V2 prototype is not known precisely, but it was probably scrapped.

The Ar 240 V3 (KK+CD) prototype was first flight tested on 9th May 1941. In comparison to the earlier two prototypes, this model had the cockpit moved forward. The rear tail-positioned dive brakes were replaced with a cone and ventral fins. Numerous engines were tested on this aircraft, including two Jumo 203 and DB 601 E. In early 1942, a number of pressure cabin tests were conducted on the V3 prototype. This aircraft also served as a test bed for the new FA-9 remote controlled system developed in cooperation between Arado and the DVL (aviation research institute), but proved to be problematic. V3 would be used operationally as a reconnaissance aircraft over England. It was piloted by Oberst Siegfried Knemeyer, and while his plane was unarmed, thanks to its high speed, he managed to avoid any confrontation with British planes. The fate of this aircraft is not known, as (depending on the sources) it could have been lost in either April 1944 or May 1942.

The V4 prototype was to be tested as a dive-bomber variant. The first test flight was made on 19th June 1941. It was powered by two 1,750 hp DB 603 A engines. It was modified with added dive brakes and was capable of carrying up to eight 50 kg (110 lb) bombs under the fuselage. Its fuselage was also elongated to 13.05 m (42 ft 9 ¾ inches). Many detailed tests with the V4 were carried out in France and in the Mediterranean. The V4 prototype was lost in August 1941 in an air accident.

The V5 (GL+QA or T5+MH) prototype made its maiden flight test in September 1941. What is interesting is that it was not built by Arado but by AGO Flugzeugwerken from Oschersleben. It was powered by two 1,175 hp DB 601 E engines and was provided with a tail cone. It was armed with two wing root MG 17 machine guns and two same caliber MG 81 machine guns placed into two (one above and under the fuselage) FA-13 type remotely controlled turrets. In late March 1942, this aircraft was given to the Aufklärungsgruppe Oberbefehlshaber der Luftwaffe (reconnaissance unit/group belonging to the Commander in Chief of the Luftwaffe). It was then, possibly in late 1942, allocated to Versuchsstelle für Höhenflüge VfH (research station for high-altitude flight).

The V6 (GL+QA or T5+KH) prototype was also built by AGO, and while most parts were ready during November 1941, the aircraft was only completed in early 1942. It was flight tested in January 1942, but if this was its first test flight is not clear. It was given to the Luftwaffe in early March 1942 and moved to Oranienburg for future tests. It was similar in appearance and equipment with the previous V5 aircraft. While it was used mostly for testing, it saw front line service during the winter of 1942/43 around the Kharkov area. The plane is listed as destroyed but under which circumstances is not known.

The V7 (DM+ZU) prototype made its first test flight in October or December 1942. It was designed to be used as the basis for the Ar 240 B high-altitude reconnaissance aircraft. It was to be provided with a pressurized cockpit and a heating system. V7 was powered by two 1,475 hp DB 605 A engines, which were specially designed to use a methanol-water injection in order to increase the engine overall performance and output. Armament consisted of two wing mounted MG 17s and a rear mounted remotely-controlled turret armed with the MG 151/20, and two 50 kg (110 lb) bombs. Operational range was 1,900 km (1,180 mi) and it a was capable of climbing to 6 km (19,685 ft) in 10 minutes and 6 seconds.

The V8 prototype was a direct copy of the V7 and possibly made its first test flight in December 1942 or March 1943 depending on the sources. The final fate of this and the previous aircraft is not known.

The V9 (BO+RC) prototype was designed as a Zerstörer (heavy fighter) aircraft. It was to be used as a test base for the planned Ar 240 C version. The V9 had redesigned longer wings and fuselage. It was powered by two DB 603 A engines which were also equipped with a methanol-water injection system. The main armament consisted of four forward and two rear MG 151/20. While this version had a great priority and was even considered for acceptance for production. This was never achieved, mostly due to a lack of necessary equipment and parts. The final fate of this aircraft is not clear, as it was possibly never even fully completed, but some sources also mention that it was lost in a landing accident.

The V10 prototype was designed as a night fighter aircraft, powered by two Jumo 213 engines. The first test flight was made in September of 1943, while more tests would be carried out up to late 1944. Arado reused this aircraft for the new improved version called Ar 440.

The V11 prototype was tested as a heavy fighter-bomber and was to be used as the base of the Ar 240 F aircraft. Due to many delays, it was actually never fully completed. It had the heaviest armament, which included a mix of MG 151 and 30 mm (1.18 inch) MK 103 cannons forward mounted, rear mounted MG 151 and 13 mm (0.5 inch) MG 131 and a bomb load of 1,800 kg (3,970 lbs). V12 was a direct copy of V11 and, as these two aircraft were never completed, both were scrapped. V13 was to be used as a test base of the Ar 240 D equipped with two 2,020 hp DB 614 engines, but none were built.

V14 was probably never fully constructed. It was to be used as a base for the Ar 240 E project and powered by two DB 627 engines. V15 was to be used in a reconnaissance role and equipped with the FuG 202 Lichtenstein radar. The V15 prototype was probably never built.

There are two more Ar 240 aircraft only known by their serial numbers (240009 and 2400010). While the usage and fate of the first aircraft is generally unknown, the second was used by the Luftwaffe operationally in the Soviet Union during 1943. It was damaged during a landing in August the same year. Its final fate is unknown.

Development of the ‘A’ Version

After a series of prototypes were built, work on the first Ar 240 A version was also undertaken by Arado. Initially, the Ar 240 A aircraft were to be powered by two 1.750 hp DB 603 A-1 engines equipped with four blade metal propellers. Armament chosen for this version consisted of two MG 151/20 (with 300 rounds of ammunition for each gun) placed in the fuselage floor and two more MG 151/20 (with same ammunition load) placed in the wings roots. There was an option for increasing the fire power by adding two more MG 151/20. For rear defence, two defense turrets equipped with MG 131 machine guns could be placed under and above the fuselage. The bomb load could have different configurations, like: One 1,000 kg (2,220 lbs) or 1,800 kg (3,930 lbs) bomb, two 500 kg (1,100 lbs) bombs, eight 50 kg (110 lbs) bombs or even 288 smaller 2.5 kg (5 lbs) incendiary and fragmentation bombs. As the Ar 240 was never accepted for service, only few of the A version aircraft were ever built.

Ar 240 A-01 (GL+QA possible marking) made its first test flight on 28th June 1942. The test flights were carried out until September 1942, when this aircraft was to be given to the Luftwaffe. After a series of further flight and weapon tests conducted at Rechlin and Tarnewitz, the Ar 240 A-01 was to be allocated to the front. It was used around Kharkov in late 1942. On 16th February 1943, Ar 240 A-01 was lost during a flight due to mechanical failure. Both crew members lost their lives during the fall.

The second Ar 240, A-02 (GL+QB), was completed by September 1942. On 13th September, the first test flight was made. The aircraft was damaged in a landing accident in late January 1943. The final fate of this aircraft is not known.

Ar 240 A-03 (DI+CY) was initially powered by two DB 601 engines, but these were replaced with BMW 801 TJ. This aircraft had a change in the cockpit configuration, with the radio operator/observer facing forward. This aircraft was stationed at Rechlin, where it was tested from May to June 1943. During testing, Ar 240 A-03 showed to have better stability and handling during flight in contrast to previous built aircrafts. From June to late July, it was tested at Brandenburg. After these tests were completed, the aircraft was allocated for operational front use. It was given to the Aufklärungsgruppe 122, a reconnaissance unit stationed in Italy at that time. This aircraft had the same fate as most previous Ar 240, as it was heavily damaged in a crash. As the damage was extensive, it was never repaired.

Ar 240 A-04 (DI+CG) was initially equipped with two DB 601 E engines, but these would be later replaced with DB 603. It made its first flight test in late September 1942. Ar 240 A-04 was allocated to the Aufklärungsgruppe 122 as a replacement for the previous aircraft. Ironically, it suffered the same fate, but it was repaired and sent back to Arado.

Ar 240 A-05 was powered by two 1880 hp BMW 801 TJ engines equipped with a Rateau type turbo supercharger. It was possibly allocated to Aufklärungsgruppe 10 stationed in the Soviet Union.

Proposed Versions

During the Ar 240’s development, the Arado officials proposed several different variants of this aircraft, but as the whole project was not going well beside a few experimental attempts, nothing came from most of them.

Ar 240 B

This was a high-altitude reconnaissance aircraft version that was to be equipped with a pressurized cockpit and a heating system. Nothing came from this project.

Ar 240 C

On 10th March 1942, Arado officials proposed that the Ar 240 should be modified for the bomber role. For this reason, the wings were modified and its size increased. The tail design was also changed, with added tail dive brakes. As the attempt to increase the size of the internal fuel tanks proved a failure, external tanks were to be used instead. The armament consisted of two MG 151/20 and two rear mounted MG 81. It is not clear, but it is possible that at least one aircraft was built.

Ar 240 D

A proposed paper project version powered by two DB 614 engines.

Ar 240 E

A proposed version with reinforced fuselage, added bomb rack for two 500 kg (1,100 lbs) bombs and increased fuel load. Different engines were also proposed for this version, including DB 603 G, DB 627 or BMW 801 J.

Ar 240 F

A proposed heavy fighter/bomber version to be powered by two DB 603 G engines.

Ar 240 mit 7.5 cm Bordwaffen

During the war, Arado and Rheinmetall discussed the installation of a 7.5 cm gun in the Ar 240. In September 1944, it appears that one plane was actually equipped with this weapon, but was probably never operationally flight tested.

Ar 240 TL

In 1942, Dr. Ing. Walther Blume proposed a heavy fighter and night-fighter version of the Ar 240. This version was designated as Ar 240 TL, which stands for Turbinen-Luftstrahltriebwerk (turbojet). This plane was to be powered by two jet engines placed in the fuselage. It remained only a paper project.

Ar 440

With the cancellation of the Ar 240 project, Arado tried to improve the Ar 240’s overall performance by building a new version, named Ar 440. The Ar 240 V10 prototype served as a base for this modification. Beside this prototype, three more were built using already existing Ar 240 components. After some time in testing, the Ar 440 was officially rejected in October 1943 by the RLM.

Overall Performance and Cancellation of the Ar 240 Project

The Ar 240 possessed several advanced characteristics like a pressurized cockpit, remote-controlled defensive turrets, traveling flaps which provided this aircraft with good low-speed overall lift performance and fuel tanks with a new self-sealing system that used thinner tank liners. But, almost from the start of first flight testing, things turned from bad to worse for this aircraft. Almost from the start, the Ar 240 was plagued with extremely bad handling on all three axes. There were also huge problems with the controls during landing, with most aircraft being lost due to this. As the aircraft proved to be dangerous to fly, it was never adopted and the initial orders for production of 40 aircraft were never materialized.

Allied Examination After the War

Strangely, despite being a rare aircraft, the Allies managed to capture at least one Ar 240 during their advance in the West in 1944/45. This aircraft was tested by Allied pilot Captain Eric Brown. He was Chief test pilot of the Royal Aircraft Establishment at Farnborough. He was involved in a British project of taking over of German war research installations and interrogating technical personnel after the war. After the war, he managed to find the single surviving Ar 240 and, after a flight on it, made a report on its performance. The source for this account is Wings Of The Luftwaffe Flying The Captured German Aircraft of World War II by Eric Brown. This aircraft would be given by the Allies to the French and its fate is unknown.

In his report, he stated. “When the Ar 240 was wheeled out of the hangar, I was struck by its angular appearance. The wings, fuselage, and tail unit all seemed to be straight-edged, with very few curves to be seen. The engines looked very large, the airscrew spinners being level with the nose of the cockpit and well ahead of the wing leading edge, while the nacelles protruded well aft of the trailing edge. I had the feeling that, if this aeroplane was as fast as it was reputed to be, then brute engine force must be the answer … The cockpit layout was neat and the instruments were quite logically arranged, while the view was good all around except downwards on either side, where the engines interfered. Take-off was quite long, even with using 20 degrees of flap, and the initial climb rate was just over 600 m/min (2,000 ft/min). Longitudinal stability was poor, lateral stability neutral, and directional stability positive. The rate of climb fell off very little as I climbed to 6,096 m (20,000 ft), where I levelled out and settled into the cruise at what I calculated was a true airspeed of 580 km/h (360 mph). In the cruise, the aeroplane could not be flown hands-off because it diverged quickly both longitudinally and laterally, and would be tiring to fly for a long time. An autopilot was fitted, although not serviceable in my case, but I believe it would have been essential for instrument flying in bad weather. On opening up to full power, I estimated that after three minutes I was hitting an impressive true airspeed of 628 km/h (390 mph), but it was obvious that the Ar 240 was a poor weapons platform. The harmony of control was terrible, with heavy ailerons, light elevators. and moderately light rudders. ….

My assessment of the Arado Ar 240 is that it was an aircraft of outstanding performance for its class and era, but it could not capitalise on this because of inferior, and indeed dangerous, handling characteristics. According to German information, it had a service ceiling of 10,500 m (34,450 ft) and a maximum range of 1,186 miles, so it had great potential as a reconnaissance intruder, and indeed it is claimed that it made such sorties over Great Britain in 1941 and 1944. Be that as it may, there can be little doubt that the Ar 240 was a failure ..”

Production Numbers

While the Ar 240 production was initially to begin in 1941, due to many problems and delays, this was not possible. While there were attempts to start production, by the end of 1942, the RLM officially terminated the program.

How many aircraft were built depends on the source. According to author G. Lang, the problem with identification of the production numbers is complicated by the fact that some prototype aircraft were allegedly modified and used for the few A-series aircraft built. Another issue, according to Lang, is that the highest known serial number production was 240018 (starting from 240000), which suggests that at least 18 were built, but it is not completely clear. Authors Ferenc A. and P. Dancey mention that at least 15 were built by 1944. Eric Brown claims that 12 prototypes were built.

Main Production and Prototypes

• Ar 240 V1-V14 – Prototypes series used to test different equipment, armament and engines.
• Ar 240 A – Was to be main production version, but only few aircraft were actually built
• Ar 240 B – High-altitude reconnaissance version, possibly few built.
• Ar 240 C – A bomber version, unknown if any were built.
• Ar 240 D – Proposed version powered by two DB 614 engines.
• Ar 240 E – Proposed modified Ar 240 version.
• Ar 240 F – Proposed heavy fighter/bomber version to be powered by two DB 603 G engines.
• Ar 440 – An improved version of the Ar 240. Only a few were built. The project was cancelled in 1943.
• Ar 240 mit 7.5 cm Bordwaffen – A proposed version armed with a 7.5 cm gun, possibly one built, but its fate is unknown.
• Ar 240TL – A jet-powered paper project.

Operators

• Germany – Operated small numbers of these aircraft, mostly for testing and reconnaissance operations.
• France – Captured one, but the fate is not known.

Conclusion

While the Ar 240 was, on paper, an excellent design with many innovations and advanced technology, in reality it did not live up to expectations. The plane proved to be dangerous during flight and many were damaged during landing, with fatal outcomes. Because the Ar 240 proved to be difficult to control, the RLM simply decided to stop the project, as it was probably unwilling to waste more time and resources on it.

Arado Ar 240 A-0 Specifications
Wingspan	14.3 m (47 ft)
Length	12.8 m (42 ft)
Height	3.95 m (13 ft)
Wing Area	31 m² (333 ft²)
Engine	Two liquid cooled twelve-cylinder 1,750 hp DB 603 A-1
Empty Weight	6,350 kg (14.000 lbs)
Maximum Takeoff Weight	10,500 kg (23,150 lbs)
Fuel Capacity	2,300 liters (607.6 US gallons)
Maximum Speed at 6 km	670 km/h (415 mph)
Cruising Speed	600 km/h (370 mph)
Range	2,200 km (1,370 mi)
Maximum Service Ceiling	11,500 m (37,730 ft)
Climb speed	Climb to 6,000 m in 9.7 minutes
Crew	Two pilot and the rear radio operator/gunner
Armament	Four 2 0mm (0.78 inch) MG 151/20 Two 13 mm (0.5 inch) MG 131 One 1,000 kg (2,220 lbs) or one 1,800 kg (3,930 lbs) bomb Or two 500 kg (1,000 lbs) bombs, Or eight 50 kg (110 lbs) bombs, Or 288 2.5 kg (5 lbs) incendiary and fragmentation bombs

Gallery

Illustrations by Ed Jackson

Credits

• Vajda, F. & Dancey, P. (1998). German aircraft industry and production, 1933-1945. Warrendale, Pa: SAE International.
• D. Nešić. (2008). Naoružanje Drugog Svetskog Rata Nemačka Beograd
• Herwig, D. & Rode, H. (2003). Luftwaffe secret projects : ground attack & special purpose aircraft. Hinckley, England: Midland Pub.
• Griehl, M. (2012). X-planes : German Luftwaffe prototypes 1930-1945. London: Frontline Books.
• Wilson, J. (2007). Propaganda postcards of the Luftwaffe. Barnsley: Pen & Sword Military.
• G. Lang. (1996) Arado AR 240, A Schiffer Military History Book.
• Brown, E. (2010). Wings of the Luftwaffe. Ottringham: Hikoki.
• Images: Luftnachrictenhelferin.blogspot.com
• Images: WarBird Photos
• Images: Luftwaffe Resource Center
• Written by Marko P.
• Edited by Stan Lucian & Captain Nemo
• Illustrations by Ed Jackson
• Colorization by Michael Jucan