From Sonic Retro
Hyper Heli-Tails is essentially Tails' version of the Rocket Shoes that are normally only available to Sonic, and will replace all monitors containing the Rocket Shoes as well as those containing the Jet Board when playing as Tails.
As soon as Tails breaks open a monitor containing the power-up, he will immediately begin flying at a greater speed than regular flying would allow, and at this point the player can use the D-Pad to control Tails' speed and altitude. While not as fast as the Rocket Shoes, it can still be tough to control Tails when flying at high speeds, and he has no means of defending himself. The power-up wears off after about five seconds, but will immediately be lost if Tails collides with a hazard.
Later on in Atomic Destroyer Zone Act 3, Tails gets a Hyper Heli-Tails monitor at the start and flies through the Zone, only to be ambushed by Metal Sonic, initiating the first of many final boss fights.