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corporate_pilot
16th Mar 2010, 13:52
Hi, just a quick question. The CRP5 given to me goes up to a tas scale of 300 kts. If im given a question as such:

Given Tas: 472
HDG: 005:
W/V: 110T/50Kts

Calculate the Drifting angle and Groundspeed.

How would I tackle such a problem with my CRP5? I assume everyone gets a similar computer, unless there is a different method to answering the above.

Thanks in advance

XX621
16th Mar 2010, 14:00
Hi, just a quick question. The CRP5 given to me goes up to a tas scale of 300 kts. If im given a question as such:
Given Tas: 472
HDG: 005:
W/V: 110T/50Kts


Doesn't your CRP-5 has a high speed slide (on the other side of the rectangular card)??

Anyway, here's how to solve (I think)..
1. Wind direction on outer wheel (110deg)
2. TAS on centre dot (472kts)
3. Mark a cross on wind velocity DOWN from TAS (on centre dot).e.g at 422kts.
4. Turn outer wheel to heading (005deg).
5. New location of your little cross gives drift left or right and ground speed. 6deg left, 490kts.

corporate_pilot
16th Mar 2010, 14:16
Nope, no high speed slide on mine, just a strange pic of a plane that resembles a piper arrow on the reverse. Think I may need to invest in a new one, thanks anyway.

ei-flyer
16th Mar 2010, 14:25
Think I may need to invest in a new one

I know the kind you mean, and yes, you definitely need to get a new one with the 'H' as well as the 'L' slide.

selfin
16th Mar 2010, 17:07
You can scale the magnitudes by a common factor. Try working out the same problem with TAS 236 kt (472 kt / 2) and wind 25 kt (50 kt / 2).

Without correcting for drift the GS should work out as 243 kt so simply multiply by 2 to get 486 kt. If correcting, GS 241 kt * 2 = 482 kt.