At what point should a VOR changeover be made from JNC VOR to MANCA intersection southbound on V187?

When navigating using VORs, a changeover point indicates where an aircraft should transition from one VOR station to another to maintain accurate navigation. In this case, the changeover from the JNC VOR to the MANCA intersection on airway V187 is determined by the distance from the JNC VOR.

The correct point for changeover at 52 NM south of JNC is based on the established changeover point procedures which are designed to ensure that the aircraft remains within range of the VOR signals. This distance allows sufficient time for the pilot to switch frequencies and confirm the signal from the new VOR without losing navigation guidance.

VOR changeover points are generally published in the chart supplements or can be determined from the aeronautical information to ensure a smooth transition between navigational aids. By ensuring the changeover happens at the appropriate distance, pilots maintain navigational awareness and safety, especially when operating in busy airspace.