June 1921 RAF D.H.10s opened an air-mail route across the desert between
Cairo and Baghdad, but the RAF was seeking a replacement for this type and
placed an order for the Avro 561, later named Andover. This was a large
aircraft to be powered by a single engine, with an empty weight about 25
per cent higher than that of the twin-engined D.H.10. When Imperial
Airways took over the route, the RAF requirement disappeared, and the
military order was cut to just three aircraft, which served at RAF Halton
in the ambulance role.
Using the wings, landing gear and tail unit of the Avro 549 Aldershot, the
Andover had a new fuselage to accommodate 12 passengers, or six stretcher
cases. The pilot, as was usual at that period, was in an open cockpit; the
navigator, who was alongside, had access to the cabin.
The Air Ministry ordered a fourth Andover, the Avro 563, in 1925. This was
configured as a 12 passenger airliner. Some cross-Channel proving flights
were undertaken when the 563 was loaned to Imperial Air ways and operated
under civil markings, but it subsequently reverted to its service serial
number, and joined the other three Andovers.
Power Plant: One 650 h.p. Rolls-Royce Condor III
Span: 68 ft 0 in
Span (folded): 27 ft 6 in
Length: 51 ft 7 in
Height: 16 ft 1½ in
Weight (All-Up): 10,685 lb
Max Speed: 110 m.p.h.
Cruise: 90 m.p.h.