A310: autopilot engage problem (and solution)

[EHM-2097 Andrei]

Hi all, you may have noticed the A310 and its impressive panels are a subject i'm very interested in. Well, yesterday I lost a full afternoon trying to figure out one problem, so now I'm posting it here along with the solution hoping it may save someone else's sunday afternoon

Behaviour: AP switch cannot be engaged.

Note that there is a "normal non-engageable" condition, properly described in the manual, but in this case the switch fill flip "ON" then "OFF" and the light indicator will flick in the process.

No, in "my" case clicking on the AP switch did nothing... but the switch flip noise, but without the switch actually moving at all.

I had the same problem in the past and I remembered solving it by switching aircraft but in a non-systematic way and with no actual technical explanation.

After many unsuccessful attempts, I eventually looked for this problem on www.hnac.org (the panel author's site) and, what do you know, there was a hint there. After a few more experiments I can now fully explain this behaviour.

The "guilty party" here is the AVIONICS switch, which simply does not exist for the HNAC panel - but the state this switch toggles on and off probably exists!

When a new aircraft is selected, FS9 does a subtle mix (too subtle for me anyway ) of initialization and state restoring from precedent flights. This way you may get a panel with avionics turned off and no actual switch to turn it on again. Funny, isn't it?

The solution exists, but it's not very elegant:
- try the AP switch as soon as you load the aircraft, if it's stuck then avionics is probably turned off.
- switch to a simple, FS9-original aircraft, that has an avionics switch;
- turn on the avionics (if battery is off, then no avionics will actually be turned on but this does not matter, it's important that the avionics switch remains "ON")
- switch back to the A310, try the AP switch, enjoy the flight etc. etc.

If you don't like this solution, you may only have to use it once. Then, after completing a flight with no further problems, shut everything down "by the book", save the flight and you'll have a cold and dark (and, most important, clean ) A310 to enjoy later.

One final word about a secondary - and completely unexpected - effect of this problem: when avionics is turned off, the NAV & ADF frequency dials cannot be used either (a click on the hotspots does nothing). At first I did not think it's the same cause, but now I'm positive about that.

Hope this helps

Andrei

[EHM-1465 Dominic]

Thanks for the information Andrei

There is another way to solve this too (and if you have the same issue with other panels that have no avionics switch) - go into the settings/key assignments menu and assign a key combination for Avionics Master Switch - then you can switch it on or off from the keyboard whether there is a switch or not on the panel

[EHM-0641 Rico]

There's a very easy way to do it...

Just go through the normal start up proces for whatever plane that has this avionics/off problem, then when you have youre engines started, simply press the FS engine start command CTRL+E and everything that is still off will automaticly switch on  

[EHM-2097 Andrei]

@Dominic: Technically you're right about assigning a key, but again... this becomes a DON'T TOUCH key during the flight, especially because should the AP get off, this would switch AT into TOGA mode into the A310.

As there are kids around here who may touch the keyboard, this is a risk too high for me


@Rico: That's interesting, I did not realize that Ctrl-E + Ctrl-F turn on and off more than just the engine(s)... good to know.

BTW, I just had a "new and exciting adventure" with the A310, but this is another story for another thread.

Cheers
Andrei

[EHM-2033 Miguel]

Originally posted by EHM-2097 Andrei
@Dominic: Technically you're right about assigning a key, but again... this becomes a DON'T TOUCH key during the flight, especially because should the AP get off, this would switch AT into TOGA mode into the A310.

Not if you put it as a combination of keys as I have done, having had this problem with other airplanes.. I have put it as Ctrl+º

[EHM-1465 Dominic]

Exactly

[EHM-2097 Andrei]

Originally posted by EHM-2033 Miguel
Not if you put it as a combination of keys as I have done, having had this problem with other airplanes.. I have put it as Ctrl+º

You got me with this one Miguel, I don't even know where the "º" is on my keyboard

[EHM-1944 Jaap]

Thanks for the explanation of the problem Andrei.I did find your solution already before (so switching planes and so on) but I did not really understand why I had to do that.
Now I do.

[EHM-1838 Andrew]

Hello
I had similar problems with no visable avionics switch in the panel i am currently using for 75and 767s and solved it by importing the AV switch from the default  FS9  737.
cheers Andy

[EHM-2033 Miguel]

Originally posted by EHM-2097 Andrei
You got me with this one Miguel, I don't even know where the "º" is on my keyboard

Portuguese keyboards are a bit different that's what you get for speaking a strange language..

[EHM-2097 Andrei]

Finally, I've adopted the "avionics master key" too, it's faster than switching planes.

AND there is a bonus, be sure you have a second key assignment to fly the A310, that is for the NAV/GPS switch.

The VOR/NAV/ILS switch seems to fullfill a similar function, but in fact whatever mode you set the NAV/GPS flag does not change. And if it is set on GPS, both VOR and ILS modes are unusable. Thus the reason to have an "emergency" key assigned.

Note that VOR and ILS A310 modes do not work on "GPS" FS mode, but the NAV mode in the A310 seems to work properly whatever the NAV/GPS flag. (I hope that my previous sentence is readable, but I'm not sure due to the "NAV" mode having opposite meanings on standard FS and A310). So, the safest when flying the A310 is to set NAV/GPS = NAV as soon as possible (you need a nearby VOR or ILS to check) and never change it again.

Another lesson learned is that for the second time i found the solution to a problem related to this aircraft + panel by searching the forums in the panel author's site. So, should anyone have any more problems, be sure you check www.hnac.org early enough.

Cheers
Andrei