In patch 7.36 for Dota 2, Gyrocopter received the Afterburner aspect. It increases movement speed upon hitting Rocket Barrage. Each new hit refreshes the effect.
To maximize movement speed, you need to select the Afterburner aspect, allowing you to accelerate up to 550. To exceed this value, you'll need the neutral item Force Boots, which removes the movement speed cap. After that, it can be increased infinitely, requiring only targets for Rocket Barrage and mana.
This and many other changes appeared in patch 7.36, which was released on the night of May 23rd. Each hero received an innate passive ability and aspects with the update marking the beginning of the second act of the "Fallen Crown" event.