Distances on Earth Surface: DGCA Air Navigation questions

A nautical mile is one minute of arc along a great circle, which ties distance straight to latitude and longitude. The ICAO value is 1,852 m, close to 6,080 ft. Heights go in feet, horizontal distances in nautical miles or kilometres.

Most of the 50 questions are worked problems: distance along a meridian, departure along a parallel, and the end position after several legs. Exam sessions have turned up 8 of them.

East and west distances shrink with latitude, since departure equals the minutes of longitude scaled by the cosine of the latitude. So a route flown south, east, north and west by equal distances does not close: its east and west legs sit at different latitudes. Change of latitude converts at 60 nautical miles per degree everywhere.