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Deals damage on the turn after it is used and has a 30% chance to flinch the target. If the move is prevented from being used after the user has charged up, then the entire move is canceled, but PP is still deducted. If the user holds the item Power Herb, the move will not require a turn to charge.
Like all moves that take a turn to charge up, Sky Attack is not a good competitive move. In fact, Sky Attack is probably the worst of the charge-up moves, due to the fact that, unlike other charge-up moves like Bounce and Shadow Force, Sky Attack does not allow the user to avoid most attacks, meaning it will most likely take a large hit while Sky Attack is charging. Sky Attack's imperfect accuracy also presents a problem, as it will sometimes give the opponent two free turns instead of one. While it does have a useful secondary effect of flinching the opponent, the chance of this happening is unreliable. Like all charge-up moves, Sky Attack allows the opponent to easily switch to a counter that can easily absorb the Sky Attack, giving the opponent momentum.
Brave Bird is a less powerful option that causes recoil damage to the user, but only takes one turn to execute.
Drill Peck is a much less powerful option, but only takes one turn to execute.