SU-33 and ground collision avoidance system: how to use it?

[guimcdo]

Hello everybody, hope you're fine.

 

I just try the ground avoidance system yesterday night, LALT+7, and I don't understand this feature, in my case, if I'm at 50m from sea level, or at 2000m from SL, when I activate this system, the ACS is activated with autothrust, and the aircraft go to pitch is up, even without obstacle on the way at 2000m altitude.

 

Is it a normal reaction?

 

I read in a different post I'm not alone in this case, but I didn't found any post dedicated for this subject.

 

What should be the normal reaction, and how to use this system?

 

Thanks for your feedback

 

Rgds

Guillaume

[Ironhand]

I haven't played around at all with it myself but, while a lot of people seem to expect it to be a sort of terrain following mode, it actually seems to be what it says it is. When it senses terrain rising up too rapidly ahead (actually, it's your altitude decreasing to rapidly in reference to the terrain) or your aircraft gets too low, it zeros out any bank angle and pitches you up. It's there automatically, when you're in RADALT hold. Not sure why it has it's own button unless it's to allow you to do a controlled pitch up if you see or sense trouble ahead with the simple push of a button. Of course, I could be completely off base but that seems to be that button's purpose and explains why the auto-throttle engages as well.

Edited November 29, 2017 by Ironhand

[guimcdo]

Should be work like that:

 

Edited December 1, 2017 by guimcdo

[Ironhand]

Should be work like that:

 

...

Would be nice, wouldn't it? :)

 

I was playing around with RADALT hold yesterday and ended up using the terrain avoidance button in exactly the way I suggested it might be used. I was coming up on some hills and realized that the aircraft wasn't pitching up--still not sure why because it should have--and hit the button. Just managed to avoid the terrain.

Edited December 1, 2017 by Ironhand