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I’m wondering what would happen if - for some reason - the pilot and his copilot were fighting over the control of an Airbus with their respective sidesticks.
Does the pilot gets the final word ? Does it works like in a traditional system, where the strongest one takes it all, but through force feedback ?

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If they were fighting, intentionally attempting to gain control over the stick, the pilot pressing the last would win. This differs from the situation in a cockpit with coupled controls, where the pilot who pushes hardest wins. So in an Airbus, a quick pilot wins from a strong pilot..

From the FCTM:

When the Pilot Flying (PF) makes an input on the sidestick, an order (an electrical signal) is sent to the fly-by-wire computer. If the Pilot Not Flying (PNF) also acts on the stick, then both signals/orders are added.

Therefore, as on any other aircraft type, PF and PNF must not act on their sidesticks at the same time. If the PNF (or Training Captain) needs to take over, the PNF must press the sidestick priority pushbutton, and announce: "I have control".

If a flight crewmember falls on a sidestick, or a mechanical failure leads to a jammed stick (there is no associate ECAM caution), the "failed" sidestick order is added to the "non failed" sidestick order.

In this case, the other not affected flight crewmember must press the sidestick priority pushbutton for at least 40 seconds, in order to deactivate the "failed" sidestick.

A pilot can at any time reactivate a deactivated stick by momentarily pressing the takeover push button on either stick.

Flight International featured an article on the A320 on 30 August 1986. It discusses the sidesticks, which were new for civil aviation at the time, and an Airbus representative makes an interesting point:

"If sidesticks were the normal way for flying aircraft, no one would even consider changing to a control column that makes it difficult for the pilot to get into his seat and which blocks his view of the instrument panel when he's there.."

It is really hard to find an unassociated person though, who is of opinion that uncoupled sticks are better than coupled sticks.

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  • $\begingroup$ There was an study which showed that dual input incident rates were the same on Boeing as Airbus aircraft. Dual input incidents are instinctive/panic reaction on both, the PM just grabs without thinking. And the pilot acts as an internal servo loop, you push to what you think is the right position. When you encounter resistance, your first instinct is to push even harder. In both cases, a uncontrolled input occurs. At least with the Airbus, you can lock out the other pilot if you hit the button. It's easy to blame the new system when it's the pilot's problem. $\endgroup$ – user71659 Nov 7 '17 at 6:36
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    $\begingroup$ @user71659 Agreed, and I totally agree that both systems are very safe and sensible. Only stating that the Airbus sticks would be the best of all worlds if all features are retained as is, plus mechanical coupling is added so that a panicking pilot is made aware of conflicting inputs via the force sensors in his fingers. $\endgroup$ – Koyovis Nov 7 '17 at 6:52

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