In the early 1960s, the German Army had an interest in a small helicopter for observation and communications duties that could be folded up compactly enough to be carried in a trailer pulled by a jeep. The Do 32, like several other light helicopters of the time such as the
Fairey Ultra-light Helicopter and the
Sud-Ouest Djinn, used rotor
tip jets to drive the rotor blades. The advantage of tip drive is the absence of torque reaction, making a tail rotor unnecessary, saving weight and simplifying control of the aircraft. Dornier used a small gas turbine to drive a compressor, which fed air out through tubes in the rotors to the tips. The Do 32 was structurally very simple, with a square section, tapering fuselage behind the pilot. The
BMW 6012L turbine and compressor were placed on top of the fuselage, immediately behind the rotor pylon. Its exhaust impinged upon a large rectangular rudder, built to resist thermal stresses, for yaw control. The horizontal tailplane was swept. The pilot sat in front of the rotor pylon, on a simple seat, carried on the lower longerons. He controlled the plane of the two-bladed rotor directly with a long curved hanging arm, and its pitch with a conventional collective pitch lever by his left side. The rudder pedals were almost straight out in front of him on a strut that also carried, beyond his feet, some simple instruments. This member also formed part of the simple three-legged undercarriage, each strut ending with an unsprung foot. All three were eventually lost in accidents with different causes. Though Dornier had hopes of large Army orders, none followed. Agricultural applications were considered, and there was a design project for the
Do 32Z, a two-seat version with a bigger engine, but no more manned Do 32s flew. The unflown fourth prototype is on display at the
Deutsches Museum, painted as the first prototype
D-HOPA. The
Do 32U was a pilotless version of the Do 32E, very similar, apart from the missing seat. The
Do 32K, developed into the
Do 34, was also an unmanned drone with compressed air-driven rotors, but without a fuselage. ==Operator==