Machine-translated by Google. Questions are authored in English.
Top

Discussion

A crosswind of \( 15 \ \mathrm{kt} \) at an approach speed of \( 120 \ \mathrm{kt} \) requires a drift angle of approximately

  • A.12.5 degrees
  • B.8.0 degrees
  • C.4.5 degrees
  • D.7.2 degrees

Answer: D

Correct answer: 7.2 degrees

The drift angle is the angle whose sine is the crosswind component over the true airspeed:

\[ \sin\theta = \frac{15}{120} = 0.125 \qquad \theta = 7.18^\circ \approx 7.2^\circ \]

That is the crab angle the aeroplane must hold on approach to track the centreline, and therefore the yaw it must be swung through in the de-crab just before touchdown. The distractor 12.5 degrees is the ratio 15/120 read as a percentage rather than a sine, a mistake worth watching for since the two are numerically close at small angles.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.