Which of the following is NOT a requirement for night VFR flight?

For night VFR (Visual Flight Rules) operations, specific equipment is mandated by regulations to enhance safety and visibility. Position lights, landing lights, and anti-collision lights are all crucial components that must be functioning and operational.

Position lights are essential for indicating the aircraft's orientation to other air traffic, helping to prevent mid-air collisions. The use of landing lights is recommended for enhancing visibility during approach and landing at night and within controlled airspace. Anti-collision lights, such as strobe lights or rotating beacons, serve the vital purpose of making the aircraft more visible to others during flight.

However, a radar system is not a requirement for night VFR flight. While radar can provide beneficial data regarding traffic and weather, its absence does not preclude the ability to legally conduct night VFR operations. Consequently, the radar system is the correct choice for the option that is NOT a requirement for night VFR flight, as it does not directly ensure safety in the same way the other listed lights do.