Which gauge is required for day VFR flight according to equipment requirements?

For day VFR (Visual Flight Rules) flight, the equipment requirements outlined by the FAA necessitate that the aircraft be equipped with a fuel gauge. A fuel gauge allows the pilot to monitor the quantity of fuel available, which is critical for assessing whether the aircraft has sufficient fuel for its intended flight. Proper fuel management is essential for ensuring safety in flight, as running out of fuel can lead to in-flight emergencies.

While other instruments like a GPS navigation system or a vertical speed indicator may be beneficial for navigation and understanding climb or descent rates, they are not mandated for day VFR flight. The weather radar, although useful in specific scenarios, is not a requirement for day VFR operations either. The emphasis on the fuel gauge aligns with the principle that pilots must always be aware of their fuel status to make informed decisions during flight planning and execution.