"Caution rotor downwash"
How much should that worry me?
Cleared for takeoff yesterday at an RAF base in the south of England... Two Merlins in formation taking off ahead, 'Clear take off. Caution rotor downwash'.
Do the same rules apply as for wake vortex, i.e. take off before their lift point, keep above? Hard to do if they take off aggressively and I'm in a 152...
Do the vortices travel down and outwards? Presumably they drift downwind?
Tim