title: Beneš-Mráz Be-150 Beta-Junior
text: # Beneš-Mráz Be-150 Beta-Junior
  
  The Beneš-Mráz Be-150 Beta-Junior was a light aerobatic trainer and racing aircraft, designed and built in Czechoslovakia in the late 1930s.
  
  ## Design and development
  
  With the success of the Beneš-Mráz Be-50 Beta-Minor Beneš decided to produce a smaller version with better performance for sport flying. A major incentive was the availability of five spare 78 kW (105 hp) Walter Junior engines, which would imbue the Be-150 with much improved vertical performance compared to the Be-50.
  
  Beneš shortened the fuselage and fitted the short-span wings of the Be-52, retaining the open cockpits and fixed, trousered, tailwheel undercarriage of the Be-50.
  
  ## Operational history
  
  The Be-150 was first flown on 5 January 1937, but was rejected by the MNO (Czechoslovak Ministry of Defense) and the three production aircraft were used for general flying club use and for air racing.
  
  ## Specifications (Be-150)
  
  Data from
  
  General characteristics
  
  * Crew: 2
  * Length: 7.55 m (24 ft 9 in)
  * Wingspan: 10.66 m (35 ft 0 in)
  * Wing area: 14 $m^2$ (150 sq ft)
  * Gross weight: 790 kg (1,742 lb)
  * Powerplant: 1 × Walter Junior 4-cyl. Air-cooled inverted in-line piston engine, 78 kW (105 hp)
  
  Performance
  
  * Maximum speed: 215 km/h (134 mph, 116 kn)
  * Cruise speed: 185 km/h (115 mph, 100 kn)
  * Range: 750 km (470 mi, 400 nmi)
  * Service ceiling: 5,500 m (18,000 ft)
  