The Arado Ar 66 was a two-seat biplane trainer that became the Luftwaffe's most numerous primary training aircraft.
Work on the Arado Ar 66 began in 1930 under the direction of Ing Walter Rethel, Arado's main designer since the Arado SD I and a former Fokker employee. After carrying out the initial design Rethel moved to Messerschmitt, and was replaced at Arado by Dipl Ing Walter Blume, who in turn moved from the bankrupt Albatros company.
The Ar 66 was a conventional aircraft for its period, with a mixed wood and metal fuselage and wing structure and fabric covering. The instructor and trainee sat in tandem open cockpits. Unlike most contemporary Arado aircraft, the Ar 66 had wings of equal size, with the lower wing staggered back. The aircraft's only distinctive feature was its tail, which had a fully movable rudder with no fixed vertical fin. The horizontal control surfaces were mounted on a raised fairing just in front of the rudder.
The first prototype, Ar 66a, made its maiden flight in 1932. It was powered by a 240hp Argus As 10C eight-cylinder liquid cooled engine. It was followed by the Ar 66b, a twin-float aircraft with the rudder extended below the fuselage. Both of these prototypes were tested at Rechlin.
Ten production Ar 66B float-planes were produced, but the main production version was the Ar 66C, which was produced in large numbers. It was very similar to the Ar 66a, and was a reliable if uninspiring training aircraft, serving with most of the initial A/B training schools.
The Ar 66C found an entirely unexpected combat role late in the Second World War. The Russians had been carrying out night-time nuisance raids using the Polikarpov U-2 biplane. This inspired the Germans to form Night-harassing squadrons (Störkampfstaffeln), before in October 1943 a larger scale effort was put in place with the creation of the Night Ground Attack Groups (Nachtschlacht Gruppen). Around 2,000 Arado Ar 66Cs were modified to carry 4lb and 8lb anti-personnel bombs, and served with most of the sixteen squadrons within the new groups, in particular with NSGr 2, 3 and 5 over the Soviet Union, NSGr 8 in Finland and NSGr 12 in Latvia.
Engine: Argus As 10c inline piston engine
Wing span: 32ft 9 3/4in
Length: 27ft 2 3/4in
Height: 9ft 7 1/2in
Empty Weight: 1,996lb
Loaded Weight: 2,933lb
Max Speed: 130mph at sea level
Cruising Speed: 109mph
Service Ceiling: 14,764ft
Range: 445 miles