Read the full explanation below: Contributed by Phil Caiger-Watson. Here’s the story: YOU GOTTA HAVE FAITH!!! This is a Category 3 ILS (Instrument Landing System) landing. We refer to them as Cat 3, Land 3 Approaches. The horizontal visibility is 200 metres (600feet). The aircraft is flown by three (3) autopilots on to the runway. The autopilots continues to keep the aircraft on the centre-line of the runway. The auto brake system stops the aircraft. The pilots monitor the performance of the autopilots and must be prepared to execute a missed approach if any of the required systems fail. The Missed Approach is accomplished by pressing a switch on the throttles. Again, the autopilot will fly the missed approach. The pilots must be ready to takeover and manually flying the missed approach if the autopilots fail. You can hear the pilots making altitude call-outs and the response is "Land 3". This is confirmation (displayed on both pilots CRT's) that all the automatic systems are in agreement and that it is safe to continue the approach. You can also hear the auto call-outs made by the aircraft at 100 feet, 50 feet and 30 feet. The last call-out you hear is the First Officer advising that the speed-brakes have extended. Speed-brakes are the panel on the upper surface of the wings which extend vertically. Their purpose is to destroy the lift created by the wings and put the aircraft weight on the tires to improve braking. credits to www.alexisparkinn.com