In the Assault phase, jetbikes are treated like normal bikes when assaulting, as they must move close to the ground in order to fight.
Bike assault moves are not slowed down by difficult terrain. However, each model entering or moving through difficult terrain, or assaulting an enemy who is standing in difficult terrain or behind an obstacle, must take a dangerous terrain test.
Так что летать они могут где угодно, но когда чарджат тех, кто стоит на земле приходится летать низко.