Hello.reporting what seems to be a bug. dont know. but have experiensed it several time.speed drops down to 0, even with pitot heat on and anti ice on.have tried it on many aircrafts. so I wonder what caused it.I can assure that the pitot heat is real button and not a false.is it a fix for it? have build 470 ciaoAnders

Hi,Many threads, some recent, about this...Pitot heat by cockpit control only ocassionally works to prevent pitot icing.Sometimes an aircraft also must have all it's de-icing/anti-icing switches on.Sometimes Shift-H must be used.In either case, it does take time for ice to "melt" if its already iced. Best procedure is to ALWAYS turn on pitot heat for any IFR flight (before departure) and if icing is expected, turn on all the anti-ice equipment as well.We have reports that with some add-on aircraft, nothing can be done to prevent pitot icing even in lighter icing conditions. In this case we recommend turning off icing via AS options (prevent all icing) and turning off random icing in clouds via FSUIPC options (if registered).In addition, certain extreme icing conditions can prevent pitot heat/deicing from defeating the ice. This would include thunderstorms and freezing rain conditions. It is best to avoid penetrating thunderstorms at all costs, and you should maintain at least 20NM distance. To avoid freezing rain, examine your aloft forecast data for temperatures and compare it to the METAR cloud and precipitation information. Precip with warmer temperatures aloft, getting colder (freezing) down low (inversion) can indicate such freezing rain. Occasionally you'll get a FZRA or FZDZ (Freezing rain/freezing drizzle) code in the METAR string to alert you as well.Hope that helps,

heythank you very much for this quick answer. -Anders-