Vulcan Roller

Apart from this being Excellent footage can someone please explain to me the Vulcan take off with airbrakes extended? I take it that it was off a roller, was it SOP to leave the Airbrakes extended?

Thanks
Matt

Look at 3 Minutes 17

http://www.youtube.com/watch?v=Ru9buhwcD2Q&playnext=1&videos=Ns8ba-Vevy0