Cripes!!! I had enough problems trying to use that stupid thing on the ground, on the nice stable desk in the exam room - the thought of trying to use it in the air scares me witless.....
(Yes, estimate new heading and ETA - your examiner wants to see that you can get into the ballpark. A gert big wind arrow on the chart really helps).
Steve (who hasn't touched a whizz wheel since getting the licence to learn) R