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Welcome to the CPL Meteorology question and answer forum. Please feel free to post your questions but more importantly also suggest answers for your forum colleagues. Bob himself or one of the other tutors will get to your question as soon as we can.
I just had a question regarding crosswinds that I couldn't wrap my head around.
" As height is decreased during a descent to land in a strong crosswind from the right, the crosswind component is likely to-
Select one:
A. Decrease
B. Reverse to come from the left
C. Remain the same
D. Increase"
Any clarification regarding this question would be great help
Thanks in advance
John.Heddles replied the topic: Crosswind question
Wind is a bit like airflow over a wing - as you get closer to the surface, you get into a boundary layer situation where the wind velocity reduces. For met you may also see a bit of change in direction but the main ask here is the reduction in speed.
There are various mathematical models around the place but the one we use routinely in flight test work is referred to as the 1/7th power law -
(ws1/ws2) = (h1/h2)^(1/7)
where ws is wind speed, h is height about the ground, and 1 and 2 refer to two different heights and their associated speeds. This works pretty well for areas with little terrain ups and downs and minimal cultural things around. You will see this equation, normally in the form of a graph, in numerous flight manuals, especially for larger aircraft.
For the question you have given, they are after (a), the wind speed decreases as you descend near the ground.
Engineering specialist in aircraft performance and weight control.
John.Heddles replied the topic: Crosswind question
If that's the worst thing which happens today, I don't think I will worry too much. Main thing is that we answer questions so that your knowledge bank increases along the learning pathway.
J
Engineering specialist in aircraft performance and weight control.