St. Louis Smash Air Force (セントルイス スマッシュエアフォース, Sento Ruisu Sumasshu Eafōsu?) is a long-range version of the St. Louis Smash Ultimate Move performed by Izuku Midoriya using the One For All Quirk.
Izuku draws out 45% of his power, then arches his leg back and performs a strong vertical roundhouse kick, firing a large blast of compressed air.
St. Louis Smash Air Force is first used by Izuku during the mission against Humarise, where he blew away a helicopter with his air pressure.
He then later used this technique to intercept a massive wave of crumbling debris created by Tomura Shigaraki's Decay Quirk.