From his Biography on his webpage :

I utilised an “enthusiastic” approach to combat flying and it soon led to trouble when my use of landing flap in the tight corners of ACM (air combat manoeuvres or dogfighting) resulted in over-stressing two sets of Sea Vixen flaps. Apart from gaining me the nick name “FLAPS”, my then Commanding Officer, the late “Dusty” Milner, ensured that I became an expert on the installation and mechanical operation of the Sea Vixen Flap system!