[jcalvinowens]

> I think a big part of it, historically, is that this control scheme provides negative feedback

> Think about the inertia of the pilot and their limbs inside the plane, acting on the controls. A sudden acceleration/jerk in the direction of the control signal will bias the operator's body to input the opposite control signal unless they are tensed up and prepared to maintain it in spite of the forces they experience.

That is completely backwards, sorry.

If the nose pitches up suddenly, the pilot tends to fall backwards, downhill. If the pilot holds the yoke like a handle, he commands further pitch up, which causes him to fall backwards more... The opposite is also true: a sudden pitch down causes an unrestrained pilot to fall forward onto the controls, commanding further pitch down, and so on.

[saltcured]

I'm not talking about some weird steady-state condition, where gravity dominates the situation. I'm talking about sudden rotations and what happens before you even have time to react.

Also, I'm talking about the planes where these control schemes were developed a century ago. In these, center of gravity and the aerodynamic center and the pilot were all relatively close to each other. This is different on some modern airliner where the pilot is perched far out in front of the wings.

In those old planes, a pitch or roll would literally rotate the plane around the pilot who momentarily continues in their original orientation. If you are sitting at your desk with hands on a keyboard and I suddenly pitch your desk up, your hands will push further into the keyboard rather than fall away. This is how the pilot would experience the sudden pitch-up as well.

[jcalvinowens]

Nope, sorry, you're wrong. I've spent hundreds of hours flying small airplanes, my earlier comment explained what actually happens in real life.

[saltcured]

Hmm, color me confused... I am not a pilot but heard this from pilot acquaintances and thought I understood the physics. I wonder if we're still talking about different time intervals though? I'm talking about the immediate effect in situations like buffeting/turbulence, in milliseconds before the pilot's nervous system can even react.

Think of the pilot and plane being in level flight and the nose suddenly pitches up. In that moment, the seat jerks away from the pilot's back and the instrument panel and windshield jerk towards the pilot. In that moment is where I believe there would be some negative input to the yoke. The plane is pitching up but the pilot is still level.

I understand that, eventually, the pilot will also pitch up, due to pressure from the seat bottom and tension from straps. In the longer time scale where that happens, the pilot's nervous system also allows them to intentionally modify their control inputs.