(Aeromotor Gustav Otto) 70 hp engine was developed from the preceding four-cylinder 50 hp type by Hans Geisenhof at the Gustav Otto Flugmaschinenwerke.

They were grouped together to a single block, joined at their cooling jackets by means of flanges and bolts.

The conjoined cylinder block incorporated a single intake duct running through the water jackets.

The intake pipe and the carburettors were enclosed by heating jackets, which were integrated into the coolant circulation.

There was a single spark plug per cylinder, with the magneto located at the control side of the engine, driven from the crankshaft via an intermediate spur gear.