When he uses the move, King K. Rool puts on a pack with a propeller attached to it, activates it, and starts to rise in the air. The move lasts a deceptively long time and covers an impressive distance, granting him great recovery power unusual for characters of his weight class. It also has a good amount of protection with the propellers, allowing him to protect himself during his ascent. This makes it harder to engage K. Rool with gimp and spike attempts when returning to the stage, but can also be used offensively to carry opponents past the upper blast line. However, the latter does carry a high risk and has no reliable way to get it off, so it's frequently a method of disrespect.
While ascending, a player can input left or right to modify the trajectory K. Rool moves at. This will also change the direction the propeller hitbox is facing, allowing for increased - and crucial - protection. As a result, swerving when an opponent attempts to challenge the attack is immensely helpful. However, by doing this, the move will lose airtime. This means that there is a trade-off for diagonal recovery distance and the extra protection, and weighing it out is very important during recovery. However, this move cannot be canceled manually: if he fails to snap to the ledge, K. Rool will continue to rise for the duration of the move, leaving him vulnerable to attack. While K. Rool flaps his arms, he will float down slower than usual. If a player wants to make him fall faster, they can press down to make him enter a helpless animation (where fast falling is also an option). This also reduces landing lag by a single frame (29 compared to Propellerpack's 30) and as a result makes it slightly less punishable. This can mean life or death in some situations.
However, the move doesn't offer any protection on the sides, which allows most characters to edgeguard K. Rool by attempting to stage spike him with a back aerial or other moves; while this can be mitigated by teching, it is susceptible to player error and leaves no protection against untechable stage spikes (although his weight and LSI make this less troublesome, with moves like Corrin's back aerial only becoming untechable at 227.5%). The propeller also doesn't clash with projectiles and items, which makes moves like Mega Man's down aerial, Villager's forward smash, Vegetable and even his own crown very effective at gimping him. Additionally, meteor smashes with long disjoints, such as Ganondorf's and especially Ivysaur's down aerial, can ignore the propeller hitbox and spike K. Rool through it, although in many cases it does require precise spacing. Overall, this move grants King K. Rool outstanding survivability and flexibility in his edgeguarding, but it can also be readily exploited by many characters, which requires him in return to be very careful when being edgeguarded himself.
Propellerpack on the ledge
The propeller hitbox usually clips though the stage, which can be useful in deterring 2-frame edgeguard attempts. If an opponent is hit by the propeller at the ledge, K. Rool can follow up with an aerial; although he doesn't get any true combos out of this at lower percentages, he can usually take advantages of frame traps and tech chases to follow up with a forward, back or up aerial. However, at higher percentages, up aerial can be true and even score a KO. However, this can being prevented simply by shielding, or even using buff inducing counters such as Revenge and Rebel's Guard. To increase the consistency of Propellerpack sniping the ledge, the K. Rool player can hold down to force the move to not ledgesnap. By holding this back until the last moment where it is possible to ledgesnap, it can effectively increase the range of the move. Propellerpack also has an unusual hitbox, with it being specifically situated on the left propeller. Due to this, the move is notoriously inconsistent regarding whether a move will beat it or not. The range differences can be taken advantage of through the prior technique as well as swerving, increasing ledgesnap consistency further.
This attack is based on the boss fights against Baron K. Roolenstein, K. Rool's alter ego in Donkey Kong Country 3: Dixie's Double Trouble!. In both fights, Dixie and Kiddy Kong must attack his pack with barrels in order to damage him. In Ultimate, K. Rool's animations for this move are similar to those in DKC3 — his helpless animation, for example, resembles the way he flapped his hands in the air upon being hit. In Donkey Kong Land III, Baron K. Roolenstein would attack with bombs and lightning bolts as well.