Twice now I've had the samme problem. I'm setup for final, A/T set with SPEED, APP, and three AP'S ON. as I try to reduce speed to VREF I've got 144 set in the speed window. Then the speed tape goes haywire, it drops all the way to 30kts then pops back to normal. It will do this a few times, but I can't get the airspeed bellow 190kts.I thought it must be icing, but even narcell heat has no effect.Any ideas?Dave FisherCYYZP4 Prescott 3.2e 478p 800mhz 1mg CPUP4P800SE Asus Motherboard1.5 gig PC3200 DDR RAM 400MHZGeforce Ti 4200/128Maxtor 80 Gig ATA 133 HD x2WDC WD800 80 Gig HDhttp://www.precisionmanuals.com/images/forum/ng_driver.jpghttp://fs2crew.com/linepilot.jpg

What is your airspeed when you enter the final? Are you deploying your flaps on schedule? Just hazarding a guess, it sounds like you are going below stall speed and the aircraft is trying to get you back to a speed above stall. But that is all I can guess at at the moment without knowing all else.

I wish it was that simple, flaps were deployed at the right time followed by speed reductions to current config. Just before GS CAPTURE I had flap 25, gear down and VREF selected. If it happens again I take a screenie.Dave FisherCYYZP4 Prescott 3.2e 478p 800mhz 1mg CPUP4P800SE Asus Motherboard1.5 gig PC3200 DDR RAM 400MHZGeforce Ti 4200/128Maxtor 80 Gig ATA 133 HD x2WDC WD800 80 Gig HDhttp://www.precisionmanuals.com/images/forum/ng_driver.jpghttp://fs2crew.com/linepilot.jpg

Sure sounds like irrational weather. Do you have FUSIPC? There's a wind smoothing check in the registered version. Also, I understand the Active Skys have something similar. Those big, dramatic airspeed changes would be a massive windsheer event in the the real world . . . but most likely a software interface glitch between MSFS and PMDG in out virtual world. (That was Vref for flaps 25, right? and you were 'on' glideslope was this was happening?)

Sam is correct, anytime the IAS drops to NILL it is weather related and most likey not having FSUIPC set correctly. This will not happen with no add-on weather programs so make sure you smooth out those winds!...............Randy J. Smith................A PROUD MEMBER OF THE PMDG BETA TEAM[h4]Evolution is a process that results in heritable changes in a population spread over many generations[/h4]

Dave,Sounds like severe icing to me. Apparently FS can depict icing so bad that not even FS pitot heat can clear it. If you have a registered version of FSUIPC you can limit your icing to something just under severe on the technical tab I think.If you don't have FSUIPC registered... DOn't fly in severe icing conditions... or register. It is well worth the money. :-)Hope it helps,

Thanks guy's I'll configure FSUIPC. BTW it was clear skys and above freezing.Dave F