Source:Avro 771 Announced in September, the Avro 771 is a 45/60-seater "Viscount replacement"-type powered by two Bristol Siddeley BS.75 ducted-fans and intended for short-range regional networks. Faster than the contemporary BAC-107 project (cruise Mach number is 0.81) the wing loading, at 651b/sq ft, is slightly higher but the Avro design will have leading-edge lift devices to reduce field length. First cost and operating costs should be less than those of the Viscount 810, i.e., basic price will, according to Avro in September last, be less than £1/2m.
Powerplant: Two Bristol Siddeley BS.75 turbofans of 7,3501b static thrust.
Dimensions: Span, 77ft 5 1/2in; length, 80ft 4 1/2in; height empty, 24ft 3in; wing area, 800 sq ft; sweepback at quarter chord, 30°.
Weights: Max take-off, 52,0001b, max landing, 50,2001b; zero fuel, 42,1001b; capacity payload, 12,0001b; weight less fuel and payload, 30,1001b.
Payload accommodation: Cabin volume (less flight deck), 2,460 cu ft; baggage and freight volume, 310 cu ft; cabin length, 44ft 4in; max internal width, 9ft 11in; headroom, 6ft 6in; max usable floor area, 413 sq ft; dimensions of largest door, 63in x 30in; max number of seats, 60 at 32in pitch.
Fuel capacity: 2,000 Imp gal (2,400 US gal).
Water capacity: 105 Imp gal (126 US gal).
Performance: Optimum-cost cruising speed, 486kt (560 m.p.h. at 25,000ft and 50,0001b); corres fuel consumption, 0.8371b/lb thrust/hr; balanced field length (max take-off weight, SL, ISA), 4,800ft; landing field length at 47,0001b, 4,500ft; range A (max payload), 1,214 n.m. (1,398 st.m.); range B (max fuel), 1,830 n.m. (2,110 st.m.); corres payload, 6,5001b; cruise Mach number, 0.81.