Unwanted pitch up 6000 ft/min

[JWS]

Hi,

I'm using the latest Boeing MCP with CPFlight and encountered a strange problem. When trying to change altitude by using V/S, pressing V/S (after having entered the new altitude) always gives a 6000 ft/min pitch up (nasty when you want to descend).
Normally pressing the V/S button should give 00, and then you can dial in positive or negative values. I tried this with the CPFLight MCP alone and then things work out just fine. As soon as I use the PM software things go wrong.

Any ideas how to deal with this?

JWS

[sas550]

Check your mcp.ini and look for this line:

AutoVS=On

Make sure it's set to on. That way You'll get a VS value that reflects your current vertical speed at the moment you press the button.

If it's already set to on I'm afraid I'm out of ideas at the moment. However, I'm sure there are others with ideas.

[JWS]

Thanks Anders,

I'll try this. Have a new setup and had to reinstall the MCP software without the old ini settings at hand. Possibly I forgot this specific setting.

Will report the result.

JWS

[PaulEMB]

JWS.
Iv'e also had this problem, but had been too busy too sort it out - my answer was to immediately transfer hand to V/S knob, and reduce V/S!

Not a fix, but it gets you back where you should be!

[Tomlin]

Okay, not to hijack, but here's a question for those 'in the know'.

When you change ALT on the autopilot and either increase or decrease its value, should the VS be 0000 FMP or some user-chosen value somewhere between 0000 and 1800 FPM?

I know where to change this in the aircraft file, just wondering what most transport aircraft should be in this regard.

[David Rogers]

Hi Eric,

Depends on the Aircraft. On most 'heavy metal', turning the alt to a new value won't trigger any V/S, until a V/S (or more likely speed/pitch decent) setting is made too.

However, having flown in a Cessna 172 in real life that had an advanced Bendix Auto-pilot, that device would immediately set a climb or descent of 700 / -700 fpm, as soon as the alt was changed.

I'm not sure about the Lear, as we know FS applies a 'default' VS of 1800 / -1800 when the Alt value is changed buy my guess would be that in the real aircraft, no V/S would be set when the Alt is changed, until a pitch mode was also set. (V/S or IAS).

Hope this is what you meant - sorry if I got it wrong and just stated the obvious to you!

[Tomlin]

Yes, that is what I was asking. I was aware of it being this way for the heavies, but wasnt sure about the LJ45. Guess I could go to my Pilot Operating Handbook? !

[JWS]

Gentlemen,

Nice to have given you an opportunity to share other info with me and others, but the fact remains that I'm still stuck with the same problem now the solution Anders gave (AutoVS=On) doesn't help.

Funny thing is that I had the whole thing working properly on my old W98SE rig with FS2002. Couple of weeks ago changed to a new machine with XP Pro and FS2004, with the latest MCP 422 and now of a sudden I get this crap. As stated before, when I use the CPFlight MCP stand alone it works like it should. Together with PM I get this problem. Maybe it's the combo? I'll do some further testing and I'm open for suggestions.

Regards,

JWS

[Trevor Hale]

Hi JWS.

I have noticed this issue and also another issue which I will go into a bit of detail following. The way I work around this issue you speak of is that prior to pressing the autopilot button I adjust my altitude and press the vs button, set the vs, and then press the A/P command button. I find this solves the issue as after the autopilot command mode is selected any further changes to altitude do not seem to create this large VS numeric.

The other issue I have is while the aircraft is on heading mode only no VS Mode, I get a porpus effect on the aircraft, like the autopilot wants to engage yet realizes it is not supposed to.

I personally feel that this issue is the new version of MCP, and urge you to try to locate an older version and see if that helps.

Best regards,

Trev

[JWS]

Trev,

thought of that also and returned to version 420. The same lame result. I bless myself that I have saved all the previous versions on CD so I can go back to .... well some time ago.

Regards,

JWS