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A32X flight control laws switching

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A32X flight control laws switching

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Old 4th Sep 2016, 05:28
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A32X flight control laws switching

Good morning,

We all know the switching conditions in normal law described in FCOM during ground-flight transition and flight-ground transition. The typical cycle in Pitch control is "Ground-Flight-Flare-Ground" with the associated switching conditions.

What is not described as far as I am aware is the Flare-to-Flight transition during a low altitude go around.

Any guru around to explain

Last edited by Lantirn; 4th Sep 2016 at 05:44.
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Old 4th Sep 2016, 05:38
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TOGA seems to do the business.
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Old 4th Sep 2016, 05:49
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It's not so simple

TOGA is required for the auto flight system to guide the aircraft during the go around, to kick the engines up and switch the FMGS to G/A mode...

But the aircraft has to satisfy some conditions to switch in flight mode again
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Old 4th Sep 2016, 05:58
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I'd guess the transition back to Flight Law is based on RA - couldn't find anything in the manuals though...
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Old 4th Sep 2016, 06:27
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Originally Posted by Sidestick_n_Rudder
I'd guess the transition back to Flight Law is based on RA - couldn't find anything in the manuals though...
For sure something with the RA.

If in the schematic the conditions (50ft and 1s passed below 50ft) are self maintained to remain in flare mode, then when above 50ft it could switch to flight mode again...(after some seconds?)
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Old 4th Sep 2016, 10:45
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When the pitch attitude exceeds 8 degrees in ground mode the five seconds begins in which the pitch and lateral controls are blended into flight mode. Cant see anything in the manuals that mentions the flare to flight mode but 8 degrees is a sensible trigger point considering the pitch attitude to aim for in a TOGA 10 manoeuvre. I don't know the actual answer looking quickly in manuals but that's my thought process on it.
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Old 4th Sep 2016, 13:21
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Lantirn
In flare mode aircraft remains in normal law where the only difference is it starts pitching down from 30 ft. When you go around as you cross 30 ft. the pitch down stops that's all. What happens if you float below 30 ft. as long as you counter the nose down it remains in normal/flight mode. After take off situation is different where it transits to normal law from direct law.
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Old 4th Sep 2016, 20:02
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Villas,

Your explanation seems reasonable.

Originally Posted by vilas
Lantirn
After take off situation is different where it transits to normal law from direct law.
You mean from ground to flight mode. Yes I got your point.
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