|Role||6-passenger commercial transport|
The Avia 51 was a three-engined high-wing cantilever monoplane designed for the Czech national airlines CLS. It was built with a duraluminium monocoque fuselage and a fixed tailwheel landing gear. Powered by three Avia Rk.12 radial engine, two fitted into the leading edges of the wing and one nose-mounted. It had a two-man flightdeck and an enclosed luxury cabin for five or six passengers, it was not large enough to stand up (5 ft 1in) but did have a separate lavatory compartment, it also had three luggage and mail compartments.
The Avia 51 entered service on the Berlin-Prague-Vienna route but with only a small passenger capacity it proved uneconomical to operate. In 1937 the aircraft were sold to the Estonian government, one appeared operating for the Spanish Republican Air Force in the Spanish Civil War and it was reported the other two were lost at sea when the freighter carrying them to Bilbao was sunk.
- Crew: 2
- Capacity: 6
- Length: 10.75 m (35 ft 3 in)
- Wingspan: 15.10 m (49 ft 6 in)
- Height: 3.50 m (11 ft 6 in)
- Wing area: 38.00 m2 (409.0 sq ft)
- Empty weight: 2,990 kg (6,592 lb)
- Max takeoff weight: 3,750 kg (8,267 lb)
- Powerplant: 3 × Avia Rk.12 7-cylinder air-cooled radial engine, 150 kW (200 hp) each
- Maximum speed: 264 km/h (164 mph; 143 kn)
- Cruising speed: 230 km/h (143 mph; 124 kn)
- Range: 780 km (485 mi; 421 nmi)
- Service ceiling: 4,000 m (13,123 ft)
- Rate of climb: 4.2 m/s (820 ft/min)
- Lift-to-drag: 10.2
- Wing loading: 94 kg/m2 (19.3 lb/sq ft)
- Orbis 1985, p. 338
- "The Avia 51 - The Czech high-performance passenger plane". Flight International: 54–55. 18 January 1934.
- The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985). Orbis Publishing.