The Wagner DOWA 81 (also known as the Pfeil 5) was an aircraft designed and built by Dr. Gerhard Wagner in order to escape East Germany. (DOWA being a contraction of “Doctor Wagner” and "81" referring to the year of the intended escape.)

East Germany, then part of the Eastern Bloc, was separated from West Germany in the Western Bloc by the inner German border and the Berlin Wall, which were heavily fortified with watchtowers, land mines, armed soldiers, and various other measures to prevent illegal crossings. East German border troops were instructed to prevent defection to West Germany by all means, including lethal force (Schießbefehl; "order to fire").

Gerhard Wagner (b. 1939) was a qualified aircraft engineer. While still a student, he had almost fled during construction of the Berlin Wall. However, he later accepted the situation. He married Ingeburg Hallbauer, and had three sons - Udo, Jörg, and Gerd. In 1961, the GDR abolished the aviation industry, leaving Wagner without any demand for his skills. He was also unable to pursue his passion of flying gliders, as the law allowed only those joining the Air Force to fly.

Wagner initially considered building a submarine to escape via the Baltic Sea, but doubted his skill in this area, and so turned to his strength: aircraft design. In order to prevent informants discovering the plan, he partitioned off the back area of his apartment kitchen using cupboards and curtains.

By mid-1979, Wagner had completed the designs for his airplane. He designed it with an enclosed cockpit and contra-rotating twin propellers in pusher configuration powered by two 19 hp engines taken from a pair of motorbikes. The motorbikes also provided the wheels for the undercarriage. He calculated the flight weight to be around 580 kilograms (himself, his wife, and his three sons), which necessitated adding landing flaps for the wings for better control. The aircraft, at just under six metres in length, was also designed to be easily disassembled into four parts, the largest of which did not exceed four metres in length, allowing it to be hidden and transported in a car trailer.

Wagner built the airplane in secret, using whatever materials he could acquire. Wagner's son Udo, who was seventeen at the time, was a motorbike enthusiast, playing for a Dresden Motoball club, and was able to secure the purchase of two heavily used MZ-ES-250/2 motorbikes for 4,500 Ostmarks. He then overhauled them, dismantled and removed the gearboxes in order to allow the crankshafts to turn the propellers, and reversed the polarity of one of the engines. The engine mufflers were rotated 90° due to the crankshaft being repositioned lengthways.

Several steps were taken to reduce the amount of noise produced by the aircraft. The propellers, designed according to plans from the 1930s, already set to rotate at around 800 kmh, were prevented from going faster than the speed of sound, and the air inlets on the carburetors were also rotated 90°, and hidden in the chassis nacelles with the mufflers. The front wheels of the motorbikes, along with their brakes and suspension, were positioned here too. Air channels were created for cooling the cylinders. Before they attached the motorbike engines, Udo and Jörg mounted one on the car trailer and used a spring balance between the car and the trailer to determine whether the thrust would be enough to power the aircraft.

Although the necessary materials (plywood, balsa wood, aluminium, plexiglass and polyester were in short supply in East Germany, the family was able to procure them from various hobby shops, which they visited in a wide area around Dresden to prevent drawing attention to themselves. Wagner's mother-in-law, who lived in the West, was brought in on the plan and smuggled in glass, silk, bearings, and saw blades for cutting the aluminium sheets. The instruments needed for flight and navigation (altimeter, airspeed indicator and compass) were either built by Wagner, smuggled from the West, or purchased on the black market.