I've been fly 767PIC for long time, and don't have big problem to it, but i recently feel enough with 1 strange behaviour of 767PIC when climb with VNAV, it mostly happened in the late stage of climb, when the wind speed or direction changing, the FD pitch bar started moving up and down until target altitude reached, of course the aircraft is moving too~do you also have this issue? and solutions? Thanks!!

I've been using PIC767 for a while now and really don't have any major issues with it, but recently I have come across one strange behaviour with vnav. While climbing my pitch showed erratic movements especially when encountering winds or changing directions until I reached my enroute altitude. You already know that my aircraft was moving. Has anyone else encountered this? If so, what solution can you give me? Thank you!! I have way to much time on my hands! Just kidding here guys LMAO Randy

ehhh...looks familiar....did i wrote it 2 times? :-hmmm

RandyLMOL,Nice job but can you do anything with the Coke-a-Cola part as well?

Do you mean something like this:(I emailed Wade Chafe and Eric Ernst about this in March already and posted a message - including pictures - on this (it was the OLD forum really: http://www.avsim.com/dcforum/DCForumID43/5200.html) but the problem obviously never was resolved and nobody else seemed to have it...):"The panel itself works flawlessly for me (and I have noticed that even the "CLB" indication now automatically changes to "CRZ", something that is not even mentioned on the WILCO-website )However there is one problem(I guess this might be a problem specific to my computer or Windows XP!?)I cannot solve: under certain circumstances the aircraft seems to have a tendency to "oscillate" around the lateral axis (in other words it starts to pitch up and down continuously). Is this something anybody else has noticed? I

Yeah, I had that problem too... I thought it was due to a different weight than the default 245, but judging but your oberservations, I'm guessing it's something else... Hopefully somebody who knows the inner-workings can shed some light on this issue... Maybe it's conversion-to-fs2002 problem like the 60% N1 taxi! LOLSincerely,Phil Geddes

I'm going to have to add my "me too" to this thread. I have noticed this for some time now. I made the same observation that it seems to start when reaching Mach .80. Doesn't happen all the time either.... I've tried to pay attention to the winds to see if that is an issue but I don't see a pattern with the winds. Happens sometimes with tailwinds, headwinds and crosswinds, both low spped and high speed.When it starts I simply switch off VNAV and go with a commanded VS and Mach setting until I reach cruise then switch back to VNAV.My system is:Windows XP ProAMD 1600+768 megs PC2100 RAMGeForce 3 Ti200

Hi MurfI have found that the occalating happens only if you do a FLCH along the route. If I go from FL370 to 410 and then back to 370, it happens and will not stop unless I go into the FMC and change the FL to reflect where I want to be. Thne is settles down and resumes level flight.I hope this helpsBill

Hi Bill,I think you may have hit the nail on the head there with FLCH. I have been in the habit lately of beginning my climb in FLCH mode and doing my climb to around 10,000 then switching to VNAV at this point. I'll have to try a couple of flights tonight one using FLCH and the other just using VNAV and see what happens.Thanks!

In my case this defintely happens when I use VNAV (without FLCH)! I can takeoff and select VNAV as soon as possible and then climb directly to the max flightlevel and will OFTEN (not always!) get the oscillation-problem. So - for me at least - this has absolutely nothing to do with FLCH (unfortunately!)Walter

Never had this problem!One suggestion.Go into FSUIPC and check/enable the smooth pressure transitions. When flying online and getting real weather the pressure from one place to another may change drammatically causing a sudden huge drop or increase in altitude causing the a/c to try and re-capture the altitude. When you enable this function in FSUIPC the pressure change is done gradually and the pressure altitude is changing slowly so the a/c doesn't have any problem!Hope this helps.George DorkofikisAthens, Greece

Thanks for your opinions~~ presently my only way to eliminate the oscillation is to switch from MACH hold to certain IAS hold when it happens..

Yes, I think the only way to avoid this at the moment, is to select a certain VS manually. I also found out in the meantime that the Boeing 757 for the Fly! 2 - simulator suffers from the same problem. If I remember correctly they said something like that it is difficult to adjust the software to behave correctly on different computers. Obviously having a faster/slower computer has something to do with it?Walter

My story:On RARE occasion, I will get an oscillation occur usually with the following conditions:1 - FS Meteo running.2 - At cruise alititude, a major change in barometric pressure on the ground occurs from one reporting station to the next - the aircraft will climb/descend to meet the new altitude. (I know this is not real world...this is what happens in the virtual world ;-) )3 - Sometimes...the aircraft does not level out but oscilates.The only way I have found to cure this is to go to the MCP, set a lower altitude (lower by at least 2000 feet), enter the new altitude in the VNAV-CRZ page, exec. Once you have levelled at the new lower altitude, set the MCP back to the higher (original)altitude and same for the VNAV-CRZ page, exec.This will solve the oscilation every time for me.I think it is caused only by massive barometer changes on the ground through Meteo/wxr interface...VNAV gets confused if the change is greater than 1000 feet or so. Changing to lower, establishing lower, then returning to original CRZ fixes it for me.If it is a persistent problem for you, try running without Meteo/wxr interface and see if it happens then. You got FSUIPC rinning with "Adjust ATIS WXR" option on and all that, eh?Rob.

How much oscillation in the altitude are you folks seeing, or is it just some subtle pitch oscillation?I'm not sure I've seen this.Lee Hetherington (KBED)