Overspeeding

[Guest xenopus]

Hi all,I noticed a few times during long haul flights that my 772 drifts into overspeed. This happened a few times when VNAV was on, and the cruise speed was set far lower than overspeed speed (Mach .82).Attached please find two pictures taken while speed drifts over the Atlantic.The first one is when MCP speed is set and the second one with VNAV speed set through the CDU.Hope you can address this in your Patch or alternatively tell me what have I done wrong.Thank you

[Guest NormanB]

Ariel,I'm not seeing overspeed in either of those?

[Guest Knikolaes]

looks like he linked the same pic twice, Norman LOL.What is that in the upper left corner? Weather program or something? Maybe that could be effecting it? Or is that what the new SB looks like now? Also are you using live weather? If so, I use ActiveSky and sometimes during wind gusts I'll get tail winds that toss me over. Happens no matter what AC I am in.

[Guest NormanB]

They are different pictures - one shows .821 mach.The bar you see is SB3 which of course will be injecting weather.Have you updated your FSUIPC in the past day or so? The latest version is supposed to sort out the weather shifts.

[Guest xenopus]

Hi Norman and Christopher,I Have not yet updated FSUIPC, but I will do it and try again.As for the photos, I know you don't see overspeed there, but you do see the discrepancy between the assigned speed restriction either by VNAV or by MCP SPD and the actual speed. These oscilations of speed sometimes throw the plane to overspeed.Now that you mentioned that weather changes can cause these symptoms, I will get the latest FSUIPC version and see if anything changes.Meanwhile, thanks and Merry Xmas

[Guest Knikolaes]

Oh DEFINATELY update that FSUIPC. I bet that's it. Users of the Feelthere 737 and a few other add-ons from other developers were havig the PRECISE same issue and the FSUIPC fixed it! I noticed a GREAT change in cruis altitude stability on over half of my add-ons after doing the interim update. I have yet to take the 777 up as I have been enacting this month's Computer Pilot 767 round robin, but I plan to take the 777 on a Computer Pilot Round Robin this weekend (it's a 747 cargo run article, but I think the 777 can do just fine for the flight :-) )

[Guest CaptainJoe]

What I see in the two pictures are an increase in airspeed due to the fact your headwind speed has dropped. I see this happen when ever the wind changes direction or speed. No worries. It is normal.

[Guest lflinares]

I've seen the same problem with changes in headwind speed, but the overspeed lasts only a few secons. I'm using Active Sky Version 6 and the latest FSUIPC.LuisKMIA

[Guest xenopus]

Thank you all,I've updated FSUIPC and it got a little better.However, I do belive these changes are as you suggest, due to shifting of headwind speeds.Happy Holidays.

[Jamie 0]

FSUIPC 3.51 is faulty, update to 3.52...Overspeeding also happens in the actual 777. Quite common when cruising near the upperband.