Ride the Chopper was a cut job for Sly Cooper in "The Black Chateau" of Sly 2: Band of Thieves. It can only be played in the demos.
Walkthrough[]
Objective[]
Ride the helicopter to reach Dimitri's rear courtyard.
The mission[]
When the helicopter passes by, jump and press 
to latch onto the landing gear. Jump from one side to the other to avoid obstacles in the way. Upon reaching Dimitri's rear courtyard, jump off the helicopter, and use Sly's cane to destroy the gate's lock. The job is complete once that is accomplished.
Note that the job will fail if you do not jump onto the chopper in time, and if you land in the wrong place.
Video[]
Sly 2 Band of Thieves - The Black Chateau - Ride the Chopper (Cut Mission)