The Airspeed Courier was a wooden low-wing cantilever cabin monoplane, incorporating numerous advanced features for the era.
One such novelty was its use of a retractable undercarriage, this was a patented innovation internally developed by Airspeed, to which the company would subsequently earn revenue from when it was adopted upon other aircraft such as the Airspeed Oxford.
It was estimated that the additional weight of the mechanism for retracting and deploying the undercarriage amounted to 30lb, while an increase in cruising speed of 20 MPH was achieved via reduced drag.
Actuation was performed by the pilot via a hand-driven hydraulic pump.
According to Taylor, the undercarriage generated considerable attention amongst the aviation press early on.
Other aspects of the aircraft, such as its structural design, were relatively conventional.
The wing’s centre section was integral with the fuselage, while the outer wing’s structure comprised a pair of spruce box spurs joined with ply former ribs.
The wing had a fabric covering, aside from the leading edge, while the fuselage comprised a plywood exterior supported by welded tubes.
The tailplane featured a cantilever fin, and was adjustable via a screw jack mechanism.
The Courier was designed to be customized for both long-distance and short-distance operations, customers were offered two alternative fuel tankage arrangements, one accommodated 28 gallons between a tank in the wing’s centre section while the other spread a total of 66 gallons across a pair of centre section tanks and a header tank.
However, the prototype was equipped with an even-greater fuel capacity of 275 gallons, although the aircraft couldn’t take off with so much fuel due to being significantly overweight, thus this expanding capacity could only ever be fully exploited mid-flight via aerial refuelling.
Multiple power plants were also offered, while the Armstrong Siddeley Lynx engine was promoted for domestic use, the Armstrong Siddeley Cheetah radial engine was also used upon most Couriers.
Owing to its advanced aerodynamics, two Couriers were used as research aircraft, one by the Royal Aircraft Establishment (RAE) and one by Napier’s, who used it for development of the Napier Rapier engine.
The RAE aircraft was modified by Airspeed via the addition of high-lift devices and drag inducers, along with modified controls, for testing purposes.
At the outbreak of the Second World War, the majority of the surviving Couriers were impressed into the Royal Air Force (RAF), where they were typically used for communications purposes.
Only a single Courier survived the conflict, and was briefly used for joyriding flights at ‘Southend on Sea’ prior to being scrapped during December 1947.
Capacity: Five passengers
Length: 28 ft 6 in (8.69 m)
Wingspan: 47 ft 0 in (14.33 m)
Height: 8 ft 9 in (2.67 m)
Wing area: 250 sq ft (23 m2)
Empty weight: 2,344 lb (1,063 kg)
Gross weight: 3,900 lb (1,769 kg)
Power plant: 1 × Armstrong Siddeley Lynx IVC air-cooled seven-cylinder radial engine, 240 hp (180 kW)
Maximum speed: 153 mph (246 km/h, 133 kn)
Cruise speed: 132 mph (212 km/h, 115 kn)
Range: 635 mi (1,022 km, 552 nmi)
Service ceiling: 13,500 ft (4,100 m)
Rate of climb: 730 ft/min (3.7 m/s)
Airspeed Aircraft since 1931-H.A. Taylor.
Aircraft of the Royal Air Force 1918-58-Owen Thetford.