I have today spoken to a friend who is a freelance cameraman for BT sport who although did witness the collision with the ground did not pay that much notice to the helicopter lifting off as such a regular thing at Leicester games. But he does clearly remember a noise before it went out of control which he described as a grinding noise like when you try and put a car into reverse while driving along he has confirmed that BT do have more footage of it lifting out of the stadium which has been passed to the Police