De Havilland Express

The de Havilland Express, also known as the de Havilland D.H.86, was a four-engined passenger aircraft manufactured by the de Havilland Aircraft Company between 1934 and 1937.

During 1933, talks between the governments of United Kingdom, India, Malaya, the Straits Settlements and Australia resulted in an agreement to establish an Empire Air Mail Service. The Australian Government called for tenders on 22 September 1933 for the Singapore-Australia legs of the route, continuing as far south as Tasmania. On the following day Qantas, anticipating success in contracting for the Singapore-Brisbane leg, placed an order with de Havilland for an as-yet non-existent aircraft to be designated the de Havilland 86, the prototype to fly by the end of January 1934. This order was soon followed by one from Holyman's Airways of Launceston, Tasmania to operate the Bass Strait leg of the service. The D.H.86 was initially styled the Express or Express Air Liner, although the name was soon discontinued.

The D.H.86 was conceptually a four-engined enlargement of the successful de Havilland Dragon, but of more streamlined appearance with tapered wings and extensive use of metal fairings around struts and undercarriage. The most powerful engine made by de Havilland, the new 200 hp (149 kW) Gipsy Six, was selected. For long-range work the aircraft was to carry a single pilot in the streamlined nose, with a wireless operator behind. Maximum seating for ten passengers was provided in the long-range type; however, the short-range Holyman aircraft were fitted with twelve seats.

The prototype D.H.86 first flew on 14 January 1934, but the Qantas representative Lester Brain immediately rejected the single-pilot layout because he anticipated pilot fatigue over long stretches, and the fuselage was promptly redesigned with a dual-pilot nose. Only four examples of the single-pilot D.H.86 were built, and of these the prototype was rebuilt as the dual-pilot prototype. When she entered service in October 1934 the first production aircraft, Holymans' single-pilot D.H.86 Miss Hobart, was the fastest British-built passenger aircraft operating anywhere in the world. Despite de Havilland's predictions to the contrary, the dual pilot type with its lengthened nose proved to be even faster.

Investigations in 1936 following a series of fatal crashes resulted in late production aircraft being built with additional fin area in the shape of vertical "Zulu Shield" extensions to the tail planes to improve lateral stability – these aircraft were designated D.H.86B.

Early proving flights were flown in 1934 by Railway Air Services which had three of the first four single-pilot aircraft built. The third aircraft built, G-ACVY Mercury, started flying between Croydon Airport, Castle Bromwich, Barton, Belfast and Renfrew on 20 August 1934. The third aircraft built was shipped to Australia for Holyman's Airways to operate the Empire air route between Melbourne and Hobart in Tasmania.

Dual-pilot D.H.86s were built for Imperial Airways and given the class name Diana. They were used on European and Empire air routes including the run from Khartoum to Lagos.

Railway Air Services (RAS) operated a fleet of seven Expresses between 1934 and 1946. RAS used the aircraft on their UK scheduled flight network including their trunk route from London Croydon via Birmingham, Manchester/Liverpool to Glasgow.