How Airplanes Land Blind in Zero Visibility

When thick fog covers an airport, the world doesn't stop flying. It switches to Autoland.

In CAT III conditions, visibility is near zero. To land safely, modern airliners lock onto the Instrument Landing System (ILS). Ground antennas shoot a horizontal "Localizer" and a vertical "Glide Slope" radio beam into the sky. The aircraft’s triple-redundant flight computers ride this invisible electronic highway down to the ground.

Because safety is critical, three independent computers calculate the landing simultaneously. If even one disagrees, it is instantly locked out. The pilots simply monitor the screens while the aircraft physically lands itself with surgical precision.

It is the ultimate proof of modern aerospace engineering.