1st pre-production aircraft with two dorsal aerial pillars. When disposed of it was reportedly acquired by Donald Campbell to use the engine for his record-breaking Bluebird K7 boat. The Gnat's fin was also incorporated into a rework of the boat's design. On 4th January 1967 Donald achieved 297 mph on his first run of the day on Coniston Water. Sadly on the required return run, K7's nose reared up, she became briefly airborne and somersaulted backwards, smashing into the lake. Donald was killed instantly and the boat was torn apart, sinking to the bottom.