{Takes place: After Season 3, Episode 2}
Rainbow Dash was doing her usual things-stunts and napping. She was sleeping on a cloud right above Twilight's house when the Princess came around and nudged her awake.
"Princess Celestia?!" asked Rainbow Dash. "You're here?"
"That I am," the princess replied. "You have been chosen as the new Princess."
"Wait, what?" asked Rainbow, who was shocked. Her mouth was hanging open.
"You, Rainbow Dash, have been chosen to be the Princess of the Sky." Celestia answered.
"But what about Ponyville? And you know...my friends, and job?"
"You will have a cloud castle here in Ponyville. You can keep your job if you wish, and control the weather everywhere in Equestria. Of course, you will be getting a horn, to."
"Sweet!" Rainbow did a few flips with her wings.
"Are you ready for the horn?" asked Celestia, wings spread wide.
"Totally!" answered Rainbow, who was acting like Pinkie Pie, bouncing around everywhere.
Celestia's horn started to glow a bright yellow. There was a flash of light, and longer cyan wings and a cyan horn appeared on Rainbow Dash, who was about as tall as Celestia.
"Awesome!" Rainbow Dash stated.
"Well, Princess Rainbow Dash, we shall have to tell your friends, shall we?"
"YES!" Rainbow practically screamed.
"Then I can all poof them here," Celestia replied. "May I?"
"Uhh, let's go to the ground. They'd fall off my cloud here." Rainbow replied.
"Okay." Celestia answered. Both, pegasus and alicorn, flew down to the ground.
Then her horn glowed, a flash of light and all six friends were standing in front of Princesses Celestia and Rainbow Dash.
"Rainbow Dash? Y-You're an ALICORN?" asked Rarity.
"Rainbow Dash was chosen to be the new Princess of the Sky. We shall go to Canterlot to announce the new princess." answered Celestia. "Rarity, would you please make the dresses?"
"Of course!!!" squealed Rarity.
"And Applejack, can you make us the food?"
"Ah'd be honored!" Applejack replied, tipping her hat.
"Pinkie Pie, could you throw us a party?"
"YIPPEEE! I"D BE GLAD TO!"
"The rest of you can help whenever you can. Does anypony have questions?"
"Yeah, one. Can I do my awesome sonic rainboom a the end?" Rainbow Dash asked.
"Sure." Celestia replied. "And off to Canterlot we go!"