Good day,During flight all of a sudden speed indicator stops (displays 000).When set to true airspeed it gives a reading, back to indicated airspeed again 000. Due to this auto trottle goes to full trottle. Flight deck companion starts extending flaps and lowering gear.Only option is to kick the Flight Deck Companion Crew out of the cockpit and adjust trottle manual. All the time GPS gives ground speed and sometimes there is a mach reading.It sometimes works to go to "select aircraft"and choose the same aircraft.I am running fs2002 pro, fsmeteo (update every 6 minutes) Radar Contact and Flight Deck Companion. Reality level to maximum, all instruments 100% reliable. Aircraft used 747 and 737.Has anybody encountered the above problem, is there anything I can do to solve this problem.Thanks in advanceMans Pfeiffer

Just out of curiosity. Did you turn your pitot heaters on? ;-)Regards

Thinking they might be frozen, yes I did try that too.Mans

However, is there a special rule during which period the heaters should be switched on, it only happens during climbing and descent.Mans

I used to have the same thing happen. It was always on a climb and generally occurred around 27,000' or higher. I got the same advice about turning on the pitot heaters during climb or descent. It worked for me. Give it a try.Good luck,Cheers,Bob

That used to happen to me all of the time during climbout or descent. Adding the PITOT HEAT ON entry to my pre-takeoff and descent checklists has resolved the problem for me as well.http://www.expedia.com/pubspec/images/airlines/smNW.gifAlex ChristoffN562ZMinneapolis, MN

Dear responders,Many thanks, I've used pitot heat occasionally so I can't say I've used it sufficiently.Will make sure it is added to my checklists rather than "ooh let's switch this one on too"Its going to be a wonderfull weekend flying from Houston to San Francisco and onwards to Anchorage with a reliable aircraft (better handling of the aircraft by the pilot).Many thanks and happy landingsMans