Weathercocking / Drift
Hi all!
About weathercocking and drift... it probably depends on which "slang" are you going to use.
In the aeronautical engineering slang... weathercocking is possible once airborne as well, not only while on the ground!
Indeed, "weathercock stability" is the nickname given to tendency of the aircraft to "naturally" align its nose into the wind. Suppose you are flying straight and level with no sideslip, in perfect simmetrical airflow conditions. Any disturbance to this airflow simmetry (ie due to a small wind gust, or turbulence, or a short input on the rudder...) would induce a sideslip, and your aircraft would react putting its nose into the wind. BTW, in most cases the fuselage+wing alone is not stable, and the yawing moment mostly comes from your vertical fin. Anyway, there are many others factors which at the end sum up to give the final response, so even a (well-designed) flying wing will be stable around its vertical axis.