In 1937, the German Air Ministry – the Reichsluftfahrtministerium (RLM) – issued a specification for a single-engine reconnaissance aircraft with optimal visual characteristics. The preferred contractor was Arado with the Ar 198, but the prototype proved unsuccessful. The eventual winner was the Focke-Wulf Fw 189 Uhu; even though its twin-boom design using two smaller engines did not match the requirement of a single engined aircraft. Blohm & Voss (Hamburger Flugzeugbau) although not invited to participate, pursued as a private venture something far more radical. The proposal of chief designer Dr. Richard Vogt was the uniquely asymmetric Ha 141 (later changed to Bv 141).

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 132N 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 Bv 141B it became asymmetrical – starboard tailplane virtually removed – to improve the rear gunner's field of view and fire.

Sources:
Brown, Eric, Captain - Wings of the Luftwaffe , 1979, Airlife Publishing Ltd., Shrewsbury
Gunston, Bill & Wood, Tony - Hitler's Luftwaffe , 1977, Salamander Books Ltd., London
The Complete Encyclodepia of World Aircraft, 1997, Barnes & Nobles Books, ISBN: 0 7607 0592 5
Wikipedia - Blohm & Voss Bv 141