A Lockheed SR-71 of the 9th RW creates fireballs in the sky as it starts its afterburners at the RAF Mildenhall Air Fete in 1986. The thick, low viscosity, high flashpoint fuel used by the Blackbiord often made it difficult to light the reheat. Here the aicraft came in fast but with power off straight into a hi-g turn causing copious amount of vapour as the vortices wrung out the humid air. Opening the throttles and selecting reheat resulted in unburnt fuel being ejected and vapourised behind the aircraft. This eventually ignited when the afterburners fired resulting in spectacular fireballs. Notice that the two afterburners did not ignite at the same time. This is what causes a “head banger”. The small canopy is only big enough for the pilot’s head and when the ’burners do not ignite together his bone-dome is banged first on one side of the canopy and then the other.
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