Some sneaky ninja-pony skills should do the trick here.
Twilight hops up and uses her new wings to try and fly up to the ventilation shaft. All goes well until she remembers something - she was still learning how to really pull off vertical flight. See, flying forward is easy because you're gliding and all, but flying upwards is a whole different story. Rainbow Dash was still giving Twilight some pointers, but whenever Twilight did try to fly up vertically without the practice, she tended to veer forward a little too much for comfort.
Sounding like a plane careening towards earth itself, Twilight flew off-balance and awkwardly tumbled forwards for the door instead of the vent. With a loud crash, she burst through the door anyway.
Well, that was some entrance.
(go to Chapter 2)