From some time I have this problem: after some minutes from takeoff (about 15.000 feet) the IAS drops to 0 so I can't use autothrottle and also using manual controls I can't have any idea about my speed. The instruments return magically to work again when I descend to a certain altitude. Does anybody have an idea about this malfuction?TIA

Are you remembering to turn on your Pitot heat? If the Pitot tube freezes up, you'll lose your airspeed indication. If the aircraft you're flying doesn't have a switch on the panel for Pitot heat, press shift-H and that will turn it on.KP

Also, if one uses certain add-on weather programs can cause some add-on aircraft issues which IAS happens to be one. Best Wishes,[h4]Randy J. Smith[/h4][h3]P M D G's 747-400[/h3][h4]coming to a runway near you[/h4][/font color]Caution! Not a real pilot, but do play one on TV ;-)AMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro | Windows Xp Pro 64 |