Hienkyaku

"Dash button while jumping. May be executed in the air."

- In-game text

Hienkyaku (飛燕脚), also known as "Flying Swallow Feet", is the special technique that Zero learns after defeating Jet Stingray in Mega Man X4. 

Trivia

 * In Tatsunoko vs. Capcom, it appears that the move can also be used to dash in any other direction other that straight forward.

Similar Techniques

 * F-Splasher from Mega Man X5

Counterpart to this Technique

 * Ground Hunter