Airbus Flight Controls Question:
Looking for some insight into A320 Flight Control Operation specifically during Normal Law, Autopilot Off, gusty wind conditions say on Final.
In "Understanding Air France 447" Bill Palmer writes "One common instance is during approach with Turbulence. Most pilots of conventionally controlled airplanes are used to instantly responding with a wind gust that tips a wing with a corresponding lateral control input. With the side stick in neutral, an Airbus will attempt to maintain a zero roll rate on its own, and will automatically input a roll command in response to the gust. Pilots who react to each bump and gust end up creating their own turbulence by wagging the sidestick back and forth faster than the airplane can respond."
Then I found something online on Airbusdriver.net. (can't post a URL here until I have 8 posts and this is my first I think).
One of the commenters says that the Airbus will look at the last bank angle and try to return to that point.
So this is really digging into the weeds and going down the rabbit hole, and I've noticed myself not thinking about any of this on a gusty final. But it still has me wondering when I'm not in the plane.
So your on final, Normal Law, AP off. Wing tips in a gust. Does the FBW flight control system stop the gust induced bank(because you didn't command it)? And does it actually attempt to return to its previous bank? Now you don't wait for all of this. You correct with sidestick. Are you augmenting the flight controls? Or does the plane sense your input and completely give you back full control? In other words...the plane with full sidestick is a 15 degree/sec roll rate. You correct with half sidestick, so what would be the roll rate command if the system is also responding to a gust?
The same thing could be asked with vertical forces. You hit a downdraft on final...see yourself going below glideslope. Since you didn't command a less that one G force, (since you are in Normal Law-Load Factor demand) with a neutral sidestick, the Flight Controls would seem to attempt to maintain one G flight by pitching up. Again, you see your glideslope going up and you react by pitching up. Are you augmenting the flight controls? Or does the system directly give you what your commanding on the Sidestick?
Thanks!