What condition must be met for the landing light to activate?

The landing light in the T-6 aircraft is designed to activate only when the landing gear is down and locked. This requirement ensures that the landing light is used when it is most beneficial, specifically during landing approaches. By activating the landing light only under this condition, it provides better visibility for both the pilots and any outside observers, ensuring safety during the critical phases of flight when landing.

The other conditions listed do not lead to the activation of the landing light; for example, having the landing gear up or the flaps deployed does not signify that the aircraft is in a landing configuration, and activating the auxiliary battery does not influence the landing light's operation. This design prevents unnecessary use of the light and focuses its use on moments when landing is imminent, reinforcing safety protocols during flight operations.