Hey guys, I haven't heard of this before but I was taking an FAA course and it mentioned that airline pilots will back up their GPS/VOR navagation means by "Flying Green Data" which says that its basically a form a dead reckoning in the event of failure of the nav systems... By knowing your heading, altitude and distance to the next fix.

Flying the Green Data? I have never heard of this... You guys do this often? Would somebody elaborate? Is this just an airline version of pilotage and dead reckoning?

Why is it called "Green Data"?