What is the key difference between VFR and IFR flight?

The key difference between VFR (Visual Flight Rules) and IFR (Instrument Flight Rules) is that VFR allows pilots to navigate and control the aircraft primarily by visual reference to the ground and surroundings. In VFR conditions, pilots can maintain visual separation from other aircraft and obstacles, relying on their ability to see and react to the environment. This means that pilots flying under VFR must be able to see and avoid obstacles and other aircraft, which is crucial for safe navigation.

IFR, on the other hand, is used when pilots must rely on instruments and navigation aids due to low visibility, clouds, or other conditions that restrict visual contact with the ground or horizon. This system allows for flying in a broader range of weather conditions, as pilots are trained to operate aircraft based on instruments regardless of visual cues.

The other options do not accurately define VFR and IFR. For instance, IFR is not limited to night flying and can be used during the day as well, regardless of weather conditions. Additionally, VFR is not restricted to small aircraft; both small and large aircraft can operate under VFR as long as they meet the required visibility and cloud clearance criteria. Lastly, IFR does not restrict flying to clear weather; it is specifically designed for use