Bally Heck:. .a bit harsh I feel, old bean. your 'facts':'..only dash capability..' and '...vast number..little or no time..' reveal you have only slight experience of the mil.not your fault but..... .I suggest there is a difference between sitting in the magnificent Concorde eating fois gras,working out one's expenses etc,etc, and being pursued by the enemy (real or exercise) whilst wearing a g-suit;oxy mask;air-vent suit;psp;bone-dome and/or immersion suit. then there is the matter of S+L vs max rate turning and the acquisiton of target(s)and escape.you properly mentioned the matter of fuel.I trust our magnificent men in big airways do not have to worry to the extent our lads do about fuel.. .it was a long time ago, my last adventure in that part of the envelope - as you call it,but being chased by two lightnings and a 104 at M1.8 does keep one on one's toes. and no fois gras either.... .by the way, the IR renewal was partly performed supersonic at medium level - about FL200. things change there. try it. <img src="tongue.gif" border="0">