A 737 performing an approach in near zero visibility, relying solely on the instruments in the cockpit in what's known as an ILS CAT IIIA approach

A 737 performing an approach in near zero visibility, relying solely on the instruments in the cockpit in what's known as an ILS Cat IIIa approach. A Cat IIIa approach requires the runway to be visible only 100ft before landing (called "decision height" because the pilot has to decide whether the landing should continue or not). If the runway is still not visible at the decision height the pilot has to initiate a missed approach. There's also Cat IIIb with an even lower decision height at less than 50ft and Cat IIIc with virtually no decision height. Currently Cat IIIc is not used because there is no way to taxy the plane on the ground. Credit: https://www.youtube.com/watch?v=RUs31hC-EjE

• A 737 performing an approach in near zero visibility, relying solely on the instruments in the cockpit in what's known as an ILS CAT IIIA approach. (from /u/iBleeedorange)