B Shoe,. .. .Sorry mate but for 757/767 you are wrong. There is an airspeed switch (80 Kts) in the deploy circuit to prevent inadvertant deployment (see Rivets post) . Also prior to simulating air mode (or jacking the a/c) there is a huge list of cb's that have to be tripped to prevent various circuits activating when they shouldn't, including the auto RAT cb. further more pulling the speed card cb does not simulate a dead donk 'cos if your in the hangar its already dead (I hope, gulp). What needs to be done is simulate engines running for which there is a switch on the speed cards themselves (or an earthing point). . .. .Finally, ATPL, provided the RAT is extended and the a/c has a forward speed of more than 150 kts the RAT will supply enough pressure to light the press lt and power the centre hydraulic system. Landing speed may of course be a little lower than this, but then that's the pilots problem!!?. .. .Cheers <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" />. . . . <small>[ 24 March 2002, 03:38: Message edited by: mono ]</small>