In the United States, aircraft usually depart the pattern either straight out along the runway heading, with a 45° turn in the direction of (or against) the crosswind leg, downwind, or with a 45° turn away from downwind.[8] In Canada, aircraft usually depart straight out along the runway heading until at circuit altitude, at which point they may turn as desired. At controlled airports, the tower typically gives instructions for what turn to make on departure.[citation needed]