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 Article: Estimating Wind    Correction / Crab Angle Your source for: Online Aviation Instrument Simulators + E6b, CR3 and other Flight Computer Calculators

Mentally Calculating the Wind Correction Angle (cont.)

IV - Comparing the mental estimation method with the exact formula

Although using the exact formula for calculating WCA would defeat the purpose of doing the mental estimation, we can use it here to compare and see how close our estimations were. The following formula produces an exact result:

a) WS = 10 knots; AWA = 40o.

Substituting the values in the equation:

The WCA calculated by the formula is 3o. This is the same result we got using mental estimation.

b) WS = 20 knots; AWA = 40o.

Substituting the values in the equation:

The WCA calculated by the formula is 6o. This is the same result we got using mental estimation.

c) WS = 5 knots; AWA = 40o.

Substituting the values in the equation:

The WCA calculated by the formula is 1o. This result we got using mental estimation was 2o so we are off by 1o.

d) WS = 10 knots; AWA = 70o

Substituting the values in the equation:

The WCA calculated by the formula is 4o. This is the same result we got using mental estimation.

e) WS = 30 knots; AWA = 90o.

Substituting the values in the equation:

The WCA calculated by the formula is 13o. This result we got using mental estimation was 12o so we are off by 1o.

f) WS = 20 knots; AWA = 10o

Substituting the values in the equation:

The WCA calculated by the formula is 0o. This result we got using mental estimation was 2o so we are off by 2o.

g) WS = 27 knots; AWA = 63o.

Substituting the values in the equation:

The WCA calculated by the formula is 11o. This result we got using mental estimation was 10o so we are off by 1o.

h) WS = 3 knots; AWA = 45o

Substituting the values in the equation:

The WCA calculated by the formula is 1o. This result we got using mental estimation was 2o so we are off by 1o.

i) 12 knots; AWA = 20o

Substituting the values in the equation:

The WCA calculated by the formula is 2o. This is the same result we got using mental estimation.

j) WS = 48 knots; AWA = 70o

Substituting the values in the equation:

The WCA calculated by the formula is 20o. This is the same result we got using mental estimation.

k) WS = 63 knots; AWA = 25o

Substituting the values in the equation:

The WCA calculated by the formula is 12o. This result we got using mental estimation was 13o so we are off by 1o.

Notice how close our estimates were, even using the simpler table on the right for the AWA correction!

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