The Dornier Do 335 Pfeil was a heavy fighter built by Dornier for Germany during World War II.The Pfeil’s performance was predicted to be better than other twin-engine designs due to its unique push-pull configuration and the lower aerodynamic drag of the in-line alignment of the two engines.
It was Nazi Germany’s fastest piston-engined aircraft of World War II.There are many advantages to this design over the more traditional system of placing one engine on each wing, the most important being power from two engines with the frontal area (and thus drag) of a single-engine design, allowing for higher performance.
It also keeps the weight of the twin powerplants near, or on, the aircraft centerline, increasing the roll rate compared to a traditional twin. In addition, a single engine failure does not lead to asymmetric thrust, and in normal flight there is no net torque, so the plane is easy to handle.
The four-surface set of cruciform tail surfaces in the Do 335’s rear fuselage design included a ventral vertical fin–rudder assembly that projected downwards from the extreme rear of the fuselage, to protect the rear propeller from an accidental ground strike on takeoff. The airplane was powered by 2 × Daimler-Benz DB 603E-1 V-12 inverted liquid-cooled piston engines powering the 3-bladed VDM, 3.5 m (11 ft 6 in) diameter constant-speed tractor and pusher propellers.