windspeed x TAS
------------------------
60
or put another way...
windspeed x (TAS / 60)
So if you have a rough GS of 90kts....then MD is 2/3 of the windspeed....
if you aircraft is travelling at 120 kts then MD is 1/2 of the windspeed
Also you dont need to be that accurate about it - the met man isnt and nobody told the choatic system we know as the weather (including wind) to behave either
Hope this helps,
FF
and whirlybord...I think 'dont need to be more accurate than 5 degs is wrong...not tried an instrument approach down an ILS recently??!?
Fly 5deg off and thats bye bye ILS...flying accurately matters - the only reason people cant fly headings properly is...
1. Failing to pick ground features to track to
2. Poor scanning of instruments in either visual or instrument flight.
If my student can accurately fly 5 deg off all the time then they certainly can fly 0deg off all the time too...