United A320 took off and lost ALL instrumentation... couldn't even locate the airport. Had to be talked down by Air Traffic... Ended up with a wheel off the pavement. http://www.businessweek.com/news/2011-04-04/united-jet-nose-gear-veers-off-runway-after-smoke-in-cockpit.html This seems to be different than pitot icing, or vertical stabilizers falling off...
ATC Chatter http://www.liveatc.net/forums/atcaviation-audio-clips/ual-497-msy-sfo-emergency-landing-at-msy/
Things happen.... remember something similar happened with a 787 a few months ago? There was also the 777 that had both engines quit just short of the airport not too long ago. Sometimes systems just like to lie..... Please note that even in the unlikely event of altitude winds of 017 / 999 knots the ground speed would not be 999 with a TAS of 256. Usually the TAS will be lying and the W/V will give you some wacky number to make it work with the GS but this was a special case..... in a Lockheed product: Image Unavailable, Please Login
Lengthy discussion/banter in this thread: United Airlines jet landed after losing primary flight instruments
