Tuesday, 13 January 2015

Maneuvering Speed.

Every good PPL knows all about this speed and the associated fun facts.

In official blurb it is indicated as Va.  It’s one of those speeds that you have to memorise for your check ride. To the lay person it is the maximum speed that you can fully load the control surfaces (full deflection) without bits breaking off your plane.

Student pilots also struggle with the fact that unlike most of the stuff we are forced to memorise, it increases with increased weight.  It’s placarded on the plane somewhere (or should be) but isn’t actually indicated on your ASI.

I always floundered to remember it. For some reason it just wouldn’t stick in my long term memory, or I could remember 2 out of the 3 weights I needed to know it for, the last one eluding my mind at the last minute. So on my flight test, I kind of cheated.

As soon as we launched into the ground portion of the test, I pulled my scratch pad towards me and discreetly wrote the three numbers in the corner while I still remembered them.

The practical applications of Va is that as soon as you hit bumpy air, you should throttle back to ensure that you are below it. Otherwise an accidental gust of wind could see you exceed it and risk structural damage.

I would just like to point out though that the above only works for airplanes.  My own research has led me to discover that for humans, manoeuvring speed is a function of both weight and temperature. You see as it gets colder, you are forced to don what feels like 20 pounds of winter gear over your normal clothes. As far as I can measure the added weight, combined with the sheer bulk of the duvet like objects, reduces your manoeuvring speed by a factor of about 50% and incidentally, increases your turning radius by about the same factor.

Yes, I’m sorry, the above post actually had very little to do with aviation and was LFEs way of saying, yet again, its bloody cold.

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