(quoted from post at 23:12:08 03/21/14) If the transponders were active at all times it would create so much screen clutter that active flights could get lost in the mess, also in the rare event that a transponder is sending corrupted data ATC may request it be turned off, or mode C turned off, the flight will not disappear from primary radar with the transponder turned off, the radar return is still there, the numbers you see in the movies on the radar screens originate from the aircraft transponder, when the data disappeared someone dropped the ball, that information should have been passed on, but wasn"t.
When you go back to where the red flag went up, it could not have been an accident, it doesn"t make sense , ACARS sent data out for hours after, along with, CPDLC, Rolls Royce claim to have engine data for about 7 hours.
If you think about it they planned it out well and learned from their mistakes, they waited long enough so cell phones would not have a signal when they made their move, but I suspect the passengers tried to make contact, I believe there was a struggle for control, they did not have to climb to 45,000 feet to kill anyone they could have sadly done that at 32,000 feet, you could take one up to 45,000 and keep her there for a while but would not be easy would have to almost have to be at VNE, speed never exceed, and still barely be above a stall speed, the plane came back close enough so the smart phones logged the users into their social media sites until the batteries died, this aircraft easily could land in less than 10,000 feet and take off with much less after they emptied it out, this would be quite easy as these planes almost fly themselves, I still doubt it"s in the ocean, it very well may be, but they went through too much to ditch in the water, what could they do with it after they got it, you can"t sell it or any parts, all have serial numbers, god be with them, but trust me, this didn"t just happen by accident, and dropping the ball along the way didn"t help.