LGNYC, as a helicopter or autogyro moves into forward flight it experiences disymmetry of lift due to differences in the airspeed between the advancing and retreating blades which causes flapback and the nose to pitch up. Also there is a difference in the direction of the flow between the front and the rear of the rotor disc (a reduction of induced flow at the front) which makes the aircraft roll towards the advancing side ( this is inflow roll or transverse flow depending on which side of the atlantic you live on).
Did anyone mention the Rugby World Cup? It's not often we get to say that England are the world champions at anything so forgive me for gloating over our colonial bretheren!