Anton Flettner, Flugzeugbau GmbH was a German

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 helicopter

Helicopter

A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

 and autogyro

Autogyro

An autogyro , also known as gyroplane, gyrocopter, or rotaplane, is a type of rotorcraft which uses an unpowered rotor in autorotation to develop lift, and an engine-powered propeller, similar to that of a fixed-wing aircraft, to provide thrust...

 manufacturer during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, founded by Anton Flettner

Anton Flettner

Anton Flettner was a German aviation engineer and inventor. He made important contributions to airplane and helicopter design...

.

Flettner aircraft

Aircraft

An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

 included:

• Flettner Fl 184
  Flettner Fl 184
  The Flettner 184 was a German night reconnaissance and anti-submarine autogyro developed during the 1930s.- Design :Its designer, Anton Flettner, designed the Fl 184 to have a single, torqueless rotor. This was done with two 30 hp engines that drove small propellers attached to the rotor...
  
   reconnaissance autogyro
  Autogyro
  An autogyro , also known as gyroplane, gyrocopter, or rotaplane, is a type of rotorcraft which uses an unpowered rotor in autorotation to develop lift, and an engine-powered propeller, similar to that of a fixed-wing aircraft, to provide thrust...
  
  , prototype
• Flettner Fl 185
  Flettner Fl 185
  The Flettner Fl 185 was an experimental German helicopter developed by Anton Flettner.This helicopter was developed in 1936 with support of the German Navy. It was powered by a BMW-Bramo Sh 14 A radial piston engine with forced-air cooling, mounted at the nose...
  
   reconnaissance helicopter, prototype
• Flettner Fl 265
  Flettner Fl 265
  -References: Nowarra, Heinz J.: Die Deutsche Luftrüstung 1933-1945, Bernard & Graeffe Verlag, Koblenz 1993, ISBN 3-7637-5464-4-External links:*...
  
   reconnaissance helicopter, prototype
• Flettner Fl 282
  Flettner Fl 282
  |- References :NotesBibliography* Coates, Steve and Jean-Christophe Carbonel. Helicopters of the Third Reich. Crowborough, UK: Classic Publications Ltd., 2002. ISBN 1-903223-24-5....
  
   Kolibri (Hummingbird), reconnaissance helicopter
• Flettner Fl 339 reconnaissance helicopter, project

Flettner's interest in aerodynamics

Aerodynamics

Aerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with...

 (specifically the Magnus effect

Magnus effect

The Magnus effect is the phenomenon whereby a spinning object flying in a fluid creates a whirlpool of fluid around itself, and experiences a force perpendicular to the line of motion...

, which produces a force from a cylinder rotating in a fluid flow) also led him to invent the Flettner rotor which he used to power a Flettner ship

Flettner ship

A rotor ship, or Flettner ship, is a ship designed to use the Magnus effect for propulsion. To take advantage of this effect, it uses rotorsails which are powered by an engine. The Magnus effect is a force acting on a spinning body in a moving airstream, which acts perpendicularly to the direction...

which crossed the Atlantic, and the Flettner ventilator which is still widely used as a cooling device for buses, vans and other commercial vehicles and which is based upon the Savonius principle.