I think the Goodyear Blimp has shrouded propellers, and I can't remember if the whole engines are turned, or just the shrouds to steer the aircraft.
Ian S C Correction: the latest (2014) one uses 3 Lycoming IO-360 engines, 2 for thrust, 1 for steering, they have reverse thrust available with the variable pitch props, Max speed 75mph.
Edited By Ian S C on 22/03/2016 10:19:21