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         The DH.114 Heron is a 
         stretched, four engined development of de Havilland's successful DH.104 
         Dove.  
          
         Only a few years later in development than the Dove on which it was 
         based, design work on the Heron began in the late 1940s, resulting in 
         the prototype's first flight on May 10 1950 (the Dove first flew in 
         1945). In designing the Heron, de Havilland made as much use of Dove 
         components as possible, and so both types feature the distinctive 
         slightly raised cockpit and separate main cabin and metal construction. 
         Initial Heron production aircraft also featured fixed undercarriage 
         (unlike the retractable gear Dove). Major differences include the four 
         185kW (250hp) Gipsy Queen engines (as opposed to two 255 to 300kW/340 
         to 400hp Gipsy Queen 70s), greater span wings, a longer and taller 
         fuselage and greater seating capacity. The first Series 1 production 
         Herons were delivered to New Zealand National Airways in 1952.  
          
         Also in 1952 the first Series 2 Heron first flew on December 14. The 
         2's main improvement over the 1 was retractable undercarriage, which 
         for a weight penalty of 75kg (165lb) increased cruising speed by 32km/h 
         (17kt), while other standard and optional improvements were minor in 
         nature. The Heron 2A was certificated for use in the USA, and an 
         equivalent 2B executive version was also offered. The 2C and equivalent 
         executive 2D have greater weights.  
          
         The Heron has been the subject of numerous conversion programs. In the 
         USA Riley converted 20 to be powered by Lycoming IO540s (eight more 
         were converted in Australia), while Prinair converted a further 29 to 
         Lycoming power.  
          
         The most ambitious Heron conversions were performed by Saunders, whose 
         ST27 conversions feature two Pratt & Whitney Canada PT6 turboprops and 
         a stretched fuselage. In addition, Tawron converted six Series 1 Herons 
         with Continental engines.  
          
         The Year: 1952  
         Crew: 2  
         Engines: 4 of 186kW D.H. Gipsy Queen 30-2 
         Wing Span: 21.79m Length: 14.78m Height: 4.75m Wing Area: 46.36m2 
         Empty Weight: 3697kg  
         Max. Weight: 6123kg 
         Speed: 294km/h  
         Ceiling: 5640m  
         Range: 1473km 
         Load: 15-17 seats.  |