June 6, 200322 yr Yesterday morning I was operating a flight from Sydney to Perth (B767-300ER) at FL360.FSMeteo had forecast winds aloft at up to 123kts and this eventually, for a period, became a reality from dead ahead. The windspeed indicator was only showing 99 but it only has a 2 digit display.The flight plan was set at a speed of Mach.85 and this was being maintained. However, during the period when the wind was >100 the airspeed indications became inconsistent much of the time, jumping erratically from .85 to .88 down to .82 and even up to .89 occasionally with the result that the overspeed alarm was sounding quite a bit. Despite this the aircraft remained reasonably stable - just a bit of rocking and rolling. Later, the wind dropped to around 94 and serenity (and sanity) returned.So what I am asking is - was that erratic speed experience as real as it gets or a bit over the top?Pat
June 7, 200322 yr Hi. Well ive been flying real world for some time now and never seen anything that eratic. The only time ive gotten the chicken clucker because of changes in winds is when im up against the barber pole flying morale speed.Besides turbs the wind speed changes are very smooth..You glance at the ehsi and notice the winds are at 105. And then the next time you glance they are at 45 and you never noticed the change.Ive never seen the mach jump around. Maybe from .854 to .862...but smoothly.
June 7, 200322 yr Author This could theoretically happen only with during extremely sudden wind change speed (and aircraft needs a few secends to adjust to the new speed). I suspect the problem may lie in the way your weather program generates winds.Michael J. Michael J.
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