Cape Town International Airport was fogged in as we approached it at 9 am local time, but we landed nonetheless. The pilot announced afterwards that the smooth landing was thanks to Boeing’s automatic landing system on the aircraft. Of course, the pilot has to be certified and the airport’s ground systems have to support the whole process as well ! I think we did a Cat II landing since the visibility was about 300m (1,500 ft). The sequence of cockpit shots are from a video clip I found on-line.
Here is a rundown of the Instrument Landing System (ILS) Categories :
Cat I : 200 feet Decision Height* (DH); 2,400 feet (or 1,800 ft) Runway Visual Range (RVR)
*The height at which point a decision must be made to either continue the approach or to execute a missed approach (abort the landing).
Cat II Restricted : 150 feet DH; 1,600 feet Runway Visual Range (RVR)
Cat II : 100 feet DH; 1,200 feet RVR
Cat III A : No DH (alert height generally 50 feet); 700 feet RVR
Cat III B : No DH (alert height generally 35 feet); 600 feet RVR
Cat III C : No DH, zero visibility – a “blind” landing. This one is almost never done, since the pilot will not be able to find the gate after landing !