Voyager Plummets (Merged)

[Jhieminga]

Originally Posted by beardy

As I understand it, the Captain could not move his control column, he surmised (without checking on the FMA) that the autopilot wouldn't let him (I have no idea why he would think that) he tried to disconnect an already disconnected autopilot using the button on the control column.

With the autopilot engaged, the solenoid in the sidestick assembly restricts the movement of the pitch and roll axes, as Airbus states: "one solenoid to introduce; in AP mode, a higher threshold to move the side stick out of the zero position."

So when the Captain tried to move the side stick he felt a restriction and took this to be the side stick solenoid, leading him to conclude that the autopilot was still engaged. So there you are, FMA stating one thing, force on the side stick saying something else. What do you do? A pitch down command would have shown him that it was not the solenoid, but that is completely counter-intuitive at that point. Moving the stick from side to side would have told him the same thing, but with one parameter already moving off the scale, introducing a second variable in the form of a roll command would not be my first idea either. Confused? I would be.

And this is where another gotcha from Airbus flight deck design turns up. All your information as a pilot comes from the screens and instruments in front of you. So that is where you logically look for help whenever the world doesn't make sense to you. With a control column right in front of you it would be relatively easy (if you would have the spare brain capacity to think of it) to glance down and perhaps spot the offending object that is blocking it. With the side stick next to your hip on the lefthand side you have to consciously move your head and look down to spot the problem. Assuming you are sitting in front of your computer at this point have a go at this yourself. Rest your left hand in the approximate position of the side stick and focus on several points on and around your computer screen. See if your peripheral vision will pick up something that is below your wrist at the edge of your vision. Now try to visualise what happens when you are startled, frightened and the adrenaline is flowing freely through your bloodstream (and perhaps your underpants), your pupils dilate, allowing more light to enter, and visual exclusion—tunnel vision—occurs, allowing greater focus but resulting in the loss of peripheral vision.

I'm pretty sure I would not have seen the camera.