What about a set of instruments that gives you an up-to-date wind vector and allows any diversion to be put into effect at any time? Easy to use in the cockpit because of the good size, employment of colour, easy to manipulate and very tough and reliable. Designed for en-route but does the pre-flight as well. That’s the Navok system--Navok.co.uk or click on the www at the top of this post.