In the Gunship Battle during the "Western Arch" section, I know you have to use force grip on the ship a few times, but I'm having trouble with the button swequence to make it work. The RT trigger locks on to the ship. the screen prompt is showing "B" being pressed repeatedly, and ampother symbol which looks like a B and pointing to the left. I seem to get a hold of the ship for a moment, but the bottons I need to have the ship slam in the tower don't seem to be coming together for me. Any suggestions?