title: Akaflieg Berlin B4 F.F.
text: # Akaflieg Berlin B4 F.F.
  
  The Akaflieg Berlin B4 F.F. was a single-seat aircraft built in Germany in the early 1930s. It was a high-wing monoplane of all-wood construction with fabric-covered foldable wings
  
  ## Design and development
  
  In 1931 the Deutsche Luftfahrt-Verband e.V. (DLV) opened a competition for an inexpensive light aircraft. Two entries were put forward; Akaflieg Berlin's B4 F.F. (D-2229) and Dipl.-Ing. Hermann Mayer's MM-1 (D-2230), with both aircraft exhibited at the 1932 Deutschen Luftsport-Ausstellung (DELA) in Berlin.
  
  Like the Mayer MM-1 the B4 F.F. was constructed at the DLV workshops in Adlershof. Design took eight months and construction a further nine.
  
  ## Specifications (B4 F.F.)
  
  Data from
  
  General characteristics
  
  * Length: 5.7 m (18 ft 8 in)
  * Wingspan: 9 m (29 ft 6 in)
  * Height: 2.4 m (7 ft 10 in)
  * Wing area: 10 $m^2$ (110 sq ft)
  * Aspect ratio: 8
  * Empty weight: 185 kg (408 lb)
  * Gross weight: 285 kg (628 lb)
  * Powerplant: 1 × Daimler F7502 , 15 kW (20 hp)
  * Propellers: 2-bladed fixed-pitch propeller
  
  Performance
  
  * Maximum speed: 125 km/h (78 mph, 67 kn)
  * Service ceiling: 3,500 m (11,500 ft)
  * g limits: +8 (ultimate load factor)
  * Wing loading: 28.5 $kg/m^2$ (5.8 lb/sq ft)
  * Power/mass: 19.18 kg/kW (31.53 lb/hp)
  