AFC Mode Release

AFC Mode basically auto-trims the aircraft so that you can release the stick and it will still fly stabley according to aircraft attitude.

 

Releasing AFC seems to reset all trims back to neutral however, because every time I release AFC, I have to scramble to manually re-trim everything, bc I'm suddenly all over the place :mad:

 

This should not be the case. From reading the manuals once AFC has trimmed the aircraft, releasing AFC should not change the trim at all; attitude should be stable.

 

Am I the only one who noticed this?

+1 Same here. It should be looked at.

It is very noticeable at high speeds and/or high altitude.

I am not seeing this behavior at all, but I always engage Alt hold along with it to do some cockpit busy work. Maybe the alt hold is setting the trim and straight AFC is bugged?

Looked at and can confirm both AFC as well as Altitude Hold work as advertised - no problems at all.

I am not seeing this behavior at all, but I always engage Alt hold along with it to do some cockpit busy work. Maybe the alt hold is setting the trim and straight AFC is bugged?

I need to check tonight. It was very obvious a while ago.

While reading up on the AFC I came across an issue I had with the SAS emergency disconnect. It may be off, as well.

If I remember correctly it used to deactivate the SAS completely (requiring to manually switch them all back on), but should in fact simply "suspend" the SAS while pressed and held. When you release the paddle switch, SAS should re-engage immediately.

As said above, did not test, yet, maybe this is addressed already.

If you activate and then deactivate AFC too quickly, it will mess with the trim in my experience - you need to activate it and leave for a second or so to allow it to do its thing. This is how I operate with it regularly and don't have any of the trim issues described.

 

Whether or not this is the correct behaviour, I can't say.

Okay, the issue is half solved.

 

If you disengage AFC through the AFC switch on the left instrument panel, trim stays the way it is, and the Harrier flys smooth as butter.

 

If you disengage AFC through the Emergency Disengage on the control stick, you lose your trim and you go all wonky, because FU! KGB HACKERS! FU!! :mad:

 

Okay, maybe it wasn't the KGB, but there should be no difference how you turn it off, mkay! :doh:

I deactivate by control input probably why I didn't notice

Looked at and can confirm both AFC as well as Altitude Hold work as advertised - no problems at all.

Yep, just tested it. AFC engage disengage works properly, as well as emergency disconnect does not effect SAS switches. Onlx thing that "seems" off is the trim when you press the paddle switch momentarily. It looks like trim is reset to center (not sure this is how the real plane acts), which causes a sharp nose down to around -5 degrees... I would expect the emergency disconnect to simply deactivate the AFC and while pressed suspend the SAS channels, but not to reset the trim?!

According to the NATOPS, depressing the Paddle should disengage the autopilot as well as interrupting the stability augmentation system and cancelling any rudder trim whilst the Paddle remains depressed. Once the Paddle is released the stability augmentation and any rudder trim is restored.

 

There is nothing in the NATOPS about a 'trim reset' occurring.

 

In other words, Shagrat it is supposed to work exactly as you expect!

Edited August 8, 2019 by Andrei Dragovic