Of the four types designed to replace the Ju 52, perhaps the most radical was the Arado Ar 232, an ugly box-like design with several novel features. Early in 1940, the Arado design team at Warnemünde began detailed design work on the new transport, which was allocated the designation Ar 232. The machine featured a pod and boom type fuselage, angular wing surfaces and twin tail fins. It was fitted with a specially-designed hydraulically-operated door in the rear of the fuselage pod which enabled large cargoes to he loaded. A maximum load of 9,920 lb (4,500 kg) could be carried, including such items as two Kübelwagen (four-seat scout cars) with their crews.
Perhaps the Ar 232's most unusual feature however was its multi-wheel static landing gear on to which the aircraft was lowered during loading and unloading. The system originally comprised eleven separate idler wheels with low-pressure tires on independently-sprung legs mounted in a row beneath the fuselage. The aircraft was provided with a conventional retractable nose wheel landing gear which could he lowered by two hydraulic rams to clear the small wheels during take off, and raised to enable the aircraft to rest on the idler wheels during loading.
The Ar 232 V1, which appeared early in 1941, and the generally-similar Ar 232 V2, were each powered by two 1,600 hp BMW 801MA radials as the forerunners of the proposed A-series. No less than 10 different subtypes of the basic Ar 232 A were projected, although they differed only in internal equipment. Originally, two BMW 801 radials had been proposed as the power plant for all Ar 232s, but following the large-scale introduction of the similarly-powered Focke-Wulf Fw 190 fighter into service, these engines became scarce, and Arado was forced to consider a substitute.
Eventually it was decided to replace the two BMW 801s with four 1,200 hp BMW-Bramo 323R-2 radials, but this decision came too late to influence the first two prototypes, the Ar 232 V3 being the first to have the BMW 323 engines. The third prototype, which received the alternative designation Ar 232 B-01, had a 5 ft 7 in (1.7 m) increase in the span of the wing center section to accommodate the extra pair of engines. The Ar 232 V3, with ten instead of eleven idler wheels, was otherwise similar to the first two prototypes. Armament comprised a 0.511 in (13 mm) MG 131 machine gun in the nose, a similar weapon in the rear of the fuselage pod above the loading door and a 0.787 in (20 mm) MG 151/20 cannon in a power-operated dorsal turret behind the cockpit transparency. These weapons could be supplemented by up to eight 0.311 in (7.9 mm) MG 34 infantry machine guns firing through the side windows.
The third prototype was the first of a batch of twenty Ar 232 B-0s which received the alternative designations Ar 232 V3 to V22. Several of these aircraft were used for experimental purposes. One was fitted with a boundary layer control system, air being sucked from the leading edge of the wing and blown over the trailing edge. The pump for this system ran on hydrogen peroxide but was never tested because all such fuel was diverted to the Messerschmitt Me 163 program. The Ar 232 V8 was fitted with four Gnome & Rhône 14M radial engines with fuel tankage increased by 606 gal (2,295 l). The Ar 232 V11 (B-09) was fitted with a non-retractable landing gear and with skis for operation in northern latitudes, and it eventually crashed in Norway.
Late in 1943, the Ar 232 V1 and V2, plus a batch of four Ar 232 B-0s, were delivered to a Staffel (squadron) commanded by Major Pelz of the Ergänzungstransportgeschwader (supplementary transport wing) under Oberstleutnant (Lieutenant Colonel) Fabiunke based on the Eastern Front. In March 1944, a second unit was equipped with the Ar 232, when a small number of aircraft were delivered to I./TG 5 (Transportgeschwader, (transport wing) based at Odessa under Major Günther Mauss. I/TG 5, which had been formed in May 1943 from the Me 323 Gruppe, was equipped in the main with the huge Messerschmitt Gigant (Giant) and a few captured Savoia-Marchetti SM.82 transports.
In Luftwaffe service, the Ar 232s were appropriately nicknamed "Tausendfüssler" ("Millipedes"), but only a small proportion of the 22 aircraft constructed saw operational service. One was retained by Arado for transporting urgently-needed supplies in connection with the Ar 234 program and was eventually flown to Britain after the war. In May 1943, the Ar 232 V8 (B-06) was used to carry meteorological equipment to Spitzbergen and subsequently saw operational service with Wekusta 5 (Wettererkundungsstaffeln, weather reconnaissance squadrons) at Banak in Norway.
Late in March 1944, an Ar 232 B-0 was delivered to 1./KG 200 (Kampfgeschwader, combat wing) and the machine was used in very small numbers by both 1. and 3. Staffel of the unit. Towards the end of 1944, the Ar 232 equipped Ergänzungsstaffel was disbanded and its aircraft transferred to Transportstaffel 5 based at Mühldorf under Hauptman (Captain) Wasserkampf. I./KG 200 and Transportstaffel 5 often operated in close co-operation and during one notable mission on September 5, 1944, an Ar 232 B-0 carrying saboteurs for Operation Zeppelin (an attempt to destroy strategically important targets around Moscow) hit a tree and caught fire near the Soviet capital.
In March 1945, Transportstaffel 5 was redesignated 14./TG 4 and possessed three Focke-Wulf Fw 200 Cs, three Junkers Ju 90s, three Piaggio P.108Ts, four Ar 232 B-0s and the Ar 232 V2; later in March, the unit was disbanded and its aircraft transferred to I./KG 200, all but one Ar 232 being destroyed on 8 May, 1945. The remaining aircraft was flown to the United Kingdom by Feldwebel (sergeant) Funk, and exhibited at the display of captured German aircraft held at Farnborough in October and November 1945.
Although only 21 Ar 232s were completed, it had been planned to switch production to the Ar 432. This was basically an Ar 232 B-0 in which wood and steel were used in place of the strategically-important aluminum and duralumin alloys. Although several sub-assemblies were completed, the Ar 432 was abandoned before it could make its first flight. The following data relate to the Ar 232 B-0."