The Napier Javelin was a British six-cylinder inline air-cooled engine designed by Frank Halford and built by D. Napier & Son. First flown in March 1934 in the prototype of the Percival Mew Gull racing aircraft, the engine was also used in the Spartan Arrow biplane and the Percival Gull.
|Manufacturer||D. Napier & Son|
|Major applications||Martin-Baker M.B.1 (one aircraft only)|
Percival Gull Four Mk IIA
In 1930 D. Napier & Son identified a market for light aircraft engines, noting that light aircraft cost much the same as their cars used to and were being purchased by much the same class of gentleman. Frank Halford had been engaged as consultant designer and now began work on an air-cooled inverted six-cylinder design. Following a change of personnel, the engine was given the go-ahead in 1932, with aircraft manufacturer de Havilland identified as a likely customer.
Development continued but only a few were sold for experimental and prototype aircraft.
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