[William_Rusher]

The turning of of the transponders is a mere flip of a switch. Transponders are almost always located on the center console of all planes and they are a simple knob with a built in stop that you have to lift up and turn to get to the emergency position( which was not done). Kinda like a dimmer switch on your dining room chandelier. To turn one off is as simple as moving it two positions, past standby to off. The plane in D.C. turned off its transponder after departing towards the west and then doubled back to D.C. It was still on the radar screens (just unidentified, since the t-ponder was off) and only dropped below radar coverage a mere seconds before impact. The planes that did go to emergency on the transponder like the Canada plane could either have turned the transponder to emergency or simply dialed in 7600 or 7700 if I remember correctly and hit ident and the radar operators would have known something was wrong as it would have dropped a box around the blip on the radar screen and made it flash. Squawking 76 or 7700 on a transponder with a hijacker in the cockpit is very unlikely, probably just flipped the tponder to emergency. Regardless of what happened with the tponder, it still is a relatively simple thing to learn, to turn it off that is. Sorry for the long ramble

[AntiTyrant]

it is not necessary to hid ident after entering in the xponder code for 'hijacking', which is not either of the codes you mentioned, btw. although they are not secrets, it's probably better to not discuss those codes to the point where they become common knowledge.