What is the difference between VFR and IFR?

The distinction between VFR (Visual Flight Rules) and IFR (Instrument Flight Rules) is fundamentally based on how pilots navigate and control their aircraft during flight. VFR is predicated on the pilot's ability to see and interpret visual references in the environment, such as the ground, other aircraft, and landmarks. Under VFR, pilots must maintain specific visibility and cloud clearance criteria to ensure safe separation from obstacles and other aircraft.

In contrast, IFR is designed for operations in conditions where visual references may be inadequate, such as flying in clouds, fog, or at night. Under IFR, pilots rely on flight instruments for navigation and control of the aircraft, which includes various instruments that provide data on altitude, airspeed, heading, and other critical flight parameters. This reliance on instruments allows pilots to operate safely in a wider range of weather conditions and situations where visual navigation is impossible.

In summary, the correct answer highlights that VFR requires visual references, enabling pilots to navigate by sight, whereas IFR fundamentally relies on the use of instruments to maintain safe flight operations when visual cues are not available. The other choices do not accurately reflect the core differences between the two rules.