Why does placing one hand on the head track stabilize you during turbulence?

Question

At 0:40, Lufthansa Capt. Joachim Schwarzenberg advises

"Whenever we get turbulence and that can always be the case during 11 hours 40 on such a long flight - that is also the flight time - The safest thing to do while in the cabin is to be one with the plane. That means if you can just support yourself on the the head track, then you are with one hand, firmly connected, it's a straight line to the floor and you can hold yourself really well.

If you just hold onto the seats like that, you will always be levered out and fall back down. So just remember this, with this you even have one free hand with which you can perhaps maneuver the cart a bit.

What's the physics behind this? Please explain in simple English. I never studied physics.

Answer 1

He's just saying that you can brace your torso, and transfer the airplane's movements into your torso better so you don't sway around relative to the floor, by holding something rigid with your hand anchored at or just above shoulder level.

If you've ridden in a subway car that is rocking back and forth while standing up, holding on to a vertical post, you've probably noticed it's better to hold the post with your hand about level with your head, vs holding it down at your waist. With your hand up high the car's motion is easy to transfer to your torso so you can stay more rigidly connected and you move as if you were part of the car. Hold it down lower and you notice your torso tends to rock about the lower anchor point and your upper body sways more relative to the post, and this makes it a lot harder to stabilize yourself.

Answer 2

Not Spinning

Occasionally, when you are not trying to move about the cabin and no one is trying to squeeze past you, you may have the luxury of placing your feet wide apart and hanging on to something not in line with your feet. Most of the time, though, your feet will be too close together, or inconveniently aligned, or alternately off the deck as you walk. Practically, you can count on our feet only as a single point of support.

Now, you will want at least one hand available to comfort and assist your passengers (otherwise you might as well remain belted into your jump seat), leaving you one hand to hold onto the airplane. This provides exactly one more point of support. Turbulence is quite random and you might get a push in any direction. Unless your wrist is exceedingly strong, you can easily be spun around the axis through your two support points.

By holding onto the overhead track you can greatly reduce the leverage operating to spin you around by keeping your center of mass very close to your support axis. But holding onto a seat back or other low handhold moves your center farther from your support axis and greatly increases that leverage.

Not Flying

When turbulence moves the cabin vertically, you can be lifted right off the deck, and you may not come back down where you were. If you press upward on the overhead track you can easily apply enough downward force to keep your feet in place. Of course you have to be prepared and react quickly, but this will come with experience.

But if you have a good grip on a seat back or seat arm, and the aircraft drops suddenly, you might even be pitched over your handhold and onto the seats. Of course the entertainment value of an upended cabin attendant will temporarily distract the passengers from their trepidation and discomfort, but as with all slapstick comedy, the risk of injury is great if it is attempted without training and practice.