Estimate the crab angle using the 10% Rule
Take the Crosswind velocity from step 5 (Figure 4.5-14 (page 12)), input it on the outer wheel (floating
decimal), and read the Crab Angle under it on the middle wheel. (Apply the 10% rule below to verify it
is a good value. In this case: 325 X 10% = 32.5, 32.5 kts ≈ 6).
The actual crosswind value of 35 and should produce a Crab Angle slightly greater than 6. It does
(6.2) (Figure 4.5-17), but always round to the nearest whole degree. Apply this CA to the TC (+ or -)
to determine the TH.
Verify the estimate!
Figure 4.5-17 Preflight Wind Calculation 6