Blohm & Voss BV 141 The Blohm & Voss BV 141 was a World War II German tactical reconnaissance aircraft . It is notable for its uncommon structural asymmetry . Although the Blohm & Voss BV 141 performed well , it was never ordered into full scale production , for reasons that included the unavailability of the preferred engine and competition from another tactical reconnaissance aircraft , the Focke - Wulf Fw 189 . Design and development . In 1937 , the German Air Ministry – the " Reichsluftfahrtministerium " ( RLM ) – issued a specification for a single - engine reconnaissance aircraft with optimal visual characteristics . The preferred contractors were Arado with their Arado Ar 198 , but the prototype proved unsuccessful . The eventual winner was the Focke - Wulf Fw 189 " Uhu " , as much as its twin - boom design did not match the requirement of a single engined aircraft . Blohm & Voss ( Hamburger Flugzeugbau ) although not invited to participate , pursued as their private venture something far more radical . The proposal of chief designer Dr . Richard Vogt was the unique asymmetric BV 141 . Design . The perspex - glazed crew gondola on the starboard side strongly resembled that found on the Fw 189 , and housed the pilot , observer and rear gunner , while the fuselage on the port side led smoothly from the BMW 132 N radial engine to a tail unit . At first glance , the placement of weight would have induced tendency to roll , but the weight was evenly supported by lift from the wings . In terms of thrust vs drag asymmetry , the countering of induced yaw was a more complicated matter . At low airspeed , it was calculated to be mostly alleviated because of a phenomenon known as P - factor , while at normal airspeed it proved to be easily controlled with trimming . The tailplane was symmetrical at first , but in the 141B it became asymmetrical – starboard tailplane virtually removed – to improve the rear gunner ' s field of view and fire . Operational history . Three prototypes and an evaluation batch of five BV 141As were produced , backed personally by Ernst Udet , but the RLM decided on 4 April 1940 that they were underpowered , although it was also noted they otherwise exceeded the requirements . By the time a batch of 12 BV 141Bs were built with the more powerful BMW 801 engines , they were too late to make an impression , as RLM already decided to put the Fw 189 into production . Indeed , an urgent need for BMW 801 engines for use in the Fw 190 fighter aircraft reduced the chance of the BV 141B being produced in quantity . Vogt came up with several other asymmetric designs , including the piston - jet P . 194 . 01 , but none of those were actually built . Several wrecked BV 141s were found by advancing Allied forces . One was captured by British forces and sent to England for examination . No examples survive today . Variants . Contrary to much that has been written , all 20 BV 141Bs ordered were produced and delivered . The complete record of BV 141 production , either a German civil registration or pre - military , four letter " Stammkennzeichen " radio code : Pre - series BV 141 B - 0 . The first to have BMW 801 engine . About 2 m longer and 2 m wider than A - 05 .