UK calls incident ‘unacceptable’ after Su-27 jet comes within six metres of unarmed RAF plane over Black Sea A Russian jet flew within six metres of an RAF spy plane flying at 500mph over the Black Sea, one of two mid-air incidents last month described as “dangerous and unacceptable” by the defence secretary, John Healey. An Su-27 jet conducted six passes in front of an unarmed RAF Rivet Joint flying close to its nose, risking a collision that could have caused a diplomatic crisis between the tw