De Havilland Heron

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The correct title of this article is de Havilland Heron. The initial letter is shown capitalized due to technical restrictions.

DeHavilland Heron

DeHavilland Heron Instrument Panel

The de Havilland DH.114 Heron was a small, propeller-driven British airliner that first flew on May 10 1950. It was a development of the de Havilland Dove, with a stretched fuselage and two more engines, for a total of four. The first deliveries were to NAC, (later part of Air New Zealand).

The Heron was of all-metal construction, and was laid out as a conventional, low-wing monoplane with tricycle undercarriage. One hundred fifty were built, exported to around 30 countries. Herons later formed the basis for various conversions, such as the Riley Turbo Skyliner and the Saunders ST-27 and ST-28.

Immediately after World War II, the aircraft manufacturer De Havilland developed the DH.104 Dove, a small, two-engined passenger aircraft intended as a replacement for the earlier Dragon Rapide, and which soon proved to be successful. As a further development, they basically enlarged the Dove; lengthened the fuselage in order to provide room for more passengers or freight, and increased the wingspan to make room for two additional engines. The resulting aircraft was supposed to be able to use many of the parts originally designed for the Dove, thus simplifying logistics for airlines employing both types.

The first Heron, model 1A suffered from a number of deficencies, as NAC soon discovered. First of all, the aircraft was generally underpowered. It was powered by four quite heavy engines (weighing approximately 400 kg each), providing as little as 250 hp. By comparison, later modifications or rebuilt aircraft (such as the Saunders ST27) had more power in one engine than the Heron had in total! Also, and contrary to the Dove, the Heron came with a fixed undercarriage, and no nosewheel steering, which simplified maintenance, but reduced the top speed.

After 51 aircraft had been built of models 1A-D, production switched to the model 2, featuring retractable landing gear, which reduced drag, and fuel consumption, and increased the top speed somewhat. Model 2A was the equivalent of 1A, the basic passenger aircraft; 1B/2B with higher maximum takeoff weight, 2C featured fully-feathering propellers, 2D had an even higher maximum takeoff weight, while the 2E was a VIP version.

After production ceased in 1963, several companies offered various conversions, with the most extreme being the Saunders ST27/28, that basically changed the look of the whole aircraft; it was reduced to two engines, the easily recognisable 'hump' over the cockpit disappeared, the shape of the windows were changed, and the wingtips were squared instead of rounded.