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Old 5th January 2024 | 13:49
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seagull967
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Joined: Mar 2007
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From: U.S.
Originally Posted by BraceBrace
What is theta-dot? Aren't you confusing Airbus and Boeing? Fly-by-wire laws on a Boeing do not change during the flare maneuver and you stay in "normal".
The flare modification was already responded to. Theta-dot is a pitch rate control, as opposed to the g-rate at higher speeds. C*, yes, same as Airbus pretty much in that regard!

Originally Posted by BraceBrace
However, (I was told this during training long time ago) and this is very true for the 777 and cause of many PIO especially in the roll during the flare: once yoke deflections become "large", the FBW system thinks the pilot really needs the aircraft to move quickly and will react in a much more "direct" way, hence much bigger aircraft reaction to stick inputs. As FlyingRoland mentions, in turbulent weather, when the pilot makes too big corrections, the FBW will also kick in hard to make the aircraft roll quickly in the desired direction. There are many videos out there of PIO on the 777 during the flare in gusty weather.

In this specific video, if the elevator is deflecting downwards that much, it is indeed probably an overcorrection of the pilot. And yes, the best is to simply let go of the control yoke (if correctly trimmed).
This is what I am trying to find out, but have yet to confirm. Nothing published says this!


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