In 1965 Bolkow Apparatebau's technical director, Dr. Hermann Mylius, began work on the design of a light all-metal two-seater training, aerobatics and glider towing aircraft, under the designation MHK-101. Clearly owing much to be Bo 208 Junior, with some commonality of components new wing and a winder fuselage to provide more room in the cabin. The prototype took off on its maiden flight on 22 December 1967, powered by a 115-hp (86-kW) Lycoming, developed as the Bolkow 209 Monsun and manufacturing of a wider fuselage to provide more room in the cabin. The prototype took off on its maiden flight on 22 December 1967 Powered by a 115-hp (86 kW) Lycoming O-235-C2A engine. It was developed as the Bolkow 209 Monsun and Manufacturing of a prototype began in January 1969, this making its first flight on 28 of May.

The main production variants were the Bo 209-150, powered  by a 150 hp (112 kW) Avco Lycoming )-320-E1C engine driving a McCauley fixed pitch or optional Hartzell constant speed propeller, and the Bo 209-160 with a 160-hp (119-kW) AVCO Lycoming IO-320-DIA fuel injection equipped engine fitted with the Hartzell propeller as standard. Both models had folding wings to reduce hangar space requirements and to facilitate towing of the aircraft behind a car; they also had retractable nosewheels and fixed main wheels. The Monsun was also available as the Bo 209S two-seat trainer, with non-folding wings and non-retraceable landing gear. Production of all models totalling 102. creasing in 1971.

Specification

Type: two-seater light monoplane

Powerplant: one 160-hp (119-kW) Avco Lycoming IQ-320-D1A flat four piston engine.

Performance: Maximum speed 170mph (127 km/h) at sea level; economic cruising speed 151 mph (113 km/h) at 8,100 ft (2440 m); service ceiling 18,100 ft (556 km/h)

Weights: empty 1,067 lb (484 kg); maximum take-off 1,807 lb (820 kg)

The MBB Bo 209 Monsun is an interesting design, of which relatively few were built in three versions. The Two Lycoming-engine models featured an optionally retractable nosewheel leg.