Beneš-Mráz Be-150 Beta-Junior

Be-150 Beta Junior
Role	Light aerobatic trainer and racing aircraft
National origin	Czechoslovakia
Manufacturer	Beneš-Mráz (Pavel Beneš and Jaroslav Mráz)
Designer	Ing. Pavel Beneš
First flight	5 January 1937
Number built	3
Developed from	Beneš-Mráz Be-50 Beta-Minor

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 m² (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)

References

• Marjánek, Pavel (1979). "Monografie: Beneš-Mraz Be-150 Beta Junior". Letectivi a Kosmonautika (in Czech). Vol. 55, no. 13. pp. 512–514.