Question

Which of the following is not one of the operational limits and autopilot requirement for a category IIIc visibility condition?

(a) Runway guidance required to taxi point

(b) Fully automatic landing system with flare

(c) Probability of catastrophic failure of less than 10−7 per hour required

(d) Decision height of 5m

I have been asked this question during a job interview.

Query is from ILS/MLS Coupled Landing System and Automatic Landing in chapter Autopilots and Flight Management Systems of Avionics

Answer 1

The correct choice is (d) Decision height of 5m

To explain I would say: The autopilot requirements and operational limits for a category III visibility conditions are a probability of catastrophic failure of less than 10−7 per hour, fully automatic landing system with flare, runway guidance required to taxi point. The decision height for a category IIIc condition is 0m. No system is yet certified for category IIIc operation.