Altitude hold mode & Vertical Speed Selection stop

[FGRA]

Please, help me out... My Altitude hold mode & Vertical Speed Selection stop working I don't know why.

[Nav]

FGRA, welcome to SimV. You don't give much information so I'm guessing - but it sounds as if you're asking the aeroplane to climb at a rate that it's not capable of, or trying to climb beyond its 'ceiling.'

The default Cessna, anyway, won't climb at a rate much better than 700 feet per minute or go much higher than 10,000 feet. The engine just doesn't give enough power.

Another problem could be mixture. In any prop, you have to start leaning off the mixture above 3,000 feet, otherwise the engine will 'die' on you and cease to give power. That's because the air gets thinner and the engine drowns in fuel at altitude if you give it the normal ground-level fuel/air mixture.

To lean the mixture, hold down 'Ctrl/Shift' and keep tapping F2. You should hear the engine speed up, then later begin to cough. Once it coughs, tap F3 a couple of times to bring it back to full power.

Hope that helps - if it doesn't, ask again and give us more information.

[dave3cu]

Doesn't sound like a problem with your install. The 2 planes, Cessna and Learjet (guessing that's what you mean by Laserjet), use different autopilots, and for both to be bad is unlikely. If your CD were physically damaged, you would likely get an error during install.

A description of the situation would be helpful. What aircraft, what altitude, airspeed and attitude (level or climb rate) are you at when engaging the AP. What VS set on AP.