Autopilot capture parameters

[Barrykensett]

After manual takeoff and I select autopilot on it does not always connect. I suspect this may be due the aircraft not being on the correct flightpath and/or altitude when I select. I therefore am more diligent in flying to the flight director and am usually successful. With my previous software I could hit AP almost anywhere and it would capture.
If my diagnosis is correct can anyone tell me what the capture parameters are?
Barry
www.a320sim.com

[jcostabal]

I was just about to write about the AP limitations and then I saw the pictures of your SIM...

[spiliot]

I've never had the AP not engage and I don't pay much attention to follow the FD closely (it tends to be more sensitive than I'd like so I control manually until I'm ready to give off control).

When you say it doesn't engage, you mean you press AP1 (or AP2) and nothing happens or you immediately hear the AP disconnect sound and it's off again? If you never get the AP disconnect then you probably don't engage it at all, might be something wrong with your joystick key assignment.

[michael1508]

i am not sure, but hadn't there been an issue with taking of in TOGA vs. Flex? I remember that I had some problems with TOGA take of's (not sure, if it was auto pilot). But since then only taking of in Flex mode. No problems since then.

[Barrykensett]

Thanks for the suggestions. When I select AP I get the disconnect sound so I am confident it is engaging and then disengaging. When I get the conditions right it engages normally. I usually take off in TOGA, I will test using flex.
Barry

[spiliot]

I rarely takeoff in TOGA but when I do I never have a problem either. I think the only issue is a single chime during takeoff roll when Flex is not set. But the Autopilot should engage irrespective of autothrust mode since it is a different system.

The only thing that I can think of to consistently disengage the AP on takeoff would be controls (joystick) not centred.

In real life engaging the AP latches the controls in the centre position (so they need extra force to move and that would be a direct indication that the pilot is taking over). If they are not in the centre position already when the autopilot kicks in it will trip off immediately.

[spiliot]

I rarely takeoff in TOGA but when I do I never have a problem either. I think the only issue is a single chime during takeoff roll when Flex is not set. But the Autopilot should engage irrespective of autothrust mode since it is a different system.

The only thing that I can think of to consistently disengage the AP on takeoff would be controls (joystick) not centred.

In real life engaging the AP latches the controls in the centre position (so they need extra force to move and that would be a direct indication that the pilot is taking over). If they are not in the centre position already when the autopilot kicks in it will trip off immediately.

[spiliot]

[Ι've been trying to reply for a while but my answer doesn't come up, hopefully you won't receive multiple replies]

Check that your joystick is centred and there's no play when you try to engage the AP. If SRS is active you should be able to engage it above 100' else above 500'. TOGA or FLEX shouldn't play a role.

[Barrykensett]

Thanks for the comments, will keep trying.
Barry
a320sim.com