Thanks for the detailed replies guys. To continue on that question I had a few queries about reverse thrusters/ thrust reversers.. .Once and for all could you tell me if 747s have Reverse Thrusters or Thrust Reversers. . .. .Also I was under the assumption that thrust reverse is only applied after nose wheel contact with the ground. However, in some pictures I saw recently on the web, it seems like thrust reverse has been applied immediately after main gear touchdown. So how does this work?