Working out the crosswind component

[s61n]

The simplest solution?

Lets keep in mind that the original request specified that you where "ON FINAL APPROACH", which probably means that you have a few other priorities besides working out the crosswind.

I had a good look at that sine tables once and found a, in my opininon, very simple system that seems to work. It is accurate within 2.5%, which, given the somewhat inaccurate wind reporting system that we have to live with, it's accuracy may be regarded as well within any practical limits.

Lets have a brief look at the cine tables, (and then forget about them):

Sine 0 degress is: 0

10 : 0.173648
20 : 0. 34202
30 : 0.5
40 : 0.642788
50 : 0.766044
60 : 0.866025
70 : 0.939693
80 : 0.984808
90 : 1


From a practical point of view, these figures are very interesting and,-
quite useless.

You will agree
That for 20 degrees: 0.34202 is very close to 0.3333 which is = 1/3
That for 40 degrees: 0.642788 is very close to 0.66666 which is = 2/3
That for 50 degrees: 0.766044 is very close to 0.75 which is = 3/4
That for 60 degrees. 0.866025 is very close to 0.9, so maybe you could multiply your given main wind by.9 and just round DOWN, ( thats veeeery close, no?)

So our new, final and complete chart could rather be:



20: 1/3
30: 1/2
40. 2/3
50: 3/4
60: .9


And thats ALL.
All above 60 degrees would be 1, or full wind strength.
A crosswind of 10 degrees is IMO if little interest anywhere below 100kts.

If you just could keep in mind the figures: 1/3, 1/2, 2/3, 3/4, .9 and the fact that your "1/3" starts at 20 degrees, you should IMHO have a perfectly adequate personal crosswind calcualtion system.

NB! Keep in mind that we, as pilots, normally seem to constantly underestimate our crosswind component.

Its more than a bit touchy to do so, but if you were to ask your highly experienced friend and collegue: You are landing on runway 18, tower reports wind 230/30. What is you effective crosswind component?
You'll find that more often than not the answer would be, "somewhere around 12-13 knots".(!)
But of course you would know better.

Finally, I think that with a little bit of cooperation, an even simpler, better system for crosswind calculation may be found, but for now, I'd very much appreciate anyones opinion of the simple procedure suggested above.

Stay safe.