Dynamic Stability & Turbulence

Posted on: August 16th, 2016 by
Comments Requested

One of the interesting things I have learned about aviation over the years is of the “stability” of an aircraft in turbulence…

It is not a “static” stability (like a three legged table sitting on firm ground… the table will not move at all). Instead, it is a “dynamic stability”… it responds in a certain way when it’s steady smooth flight is disturbed by turbulence, and the way it responds is based upon the design of the aircraft.

Think about throwing darts at a dartboard… a dart is designed with it’s centre of gravity (the bulk of it’s mass) forward and feathers at the back to keep it straight. If you throw it smooth it will fly straight and true, no problem. If you throw it wobbly it will wobble through the air but eventually straighten it’s flight and hit the board point-first.

An airplane is much the same… encounter some turbulence and it might wobble a bit, but it will sort itself out in the same way a dart does. It is designed that way; it has no choice.

Yes, it might be a little uncomfortable… we earthlings evolved on the stable ground so we might find such jostling unpleasant. Perhaps the worst of it is the unexpectedness of the sensation, a sensation that (because it is unexpected and seemingly random) can be troubling and make us believe the aircraft is out of control.

And yet it is not… this dynamic stability is safe and it works, reliably, every time. Like a dart (or an arrow) your airplane will invariably sort itself out and fly straight because it is designed to… it can do nothing else (irrespective of your thoughts and emotions about the experience!).

(if you want to learn more about the particular modes of dynamic stability in an aircraft you could try this Wikipedia page… or you could just take my word for it!).