A method and system for visually guiding an aircraft in its landing
approach to a runway having an approach area equipped with approach
lights operable in off, low, medium, and high intensity states. The
lights are communicated with a secondary side of a transformer, which has
a primary side with low, medium, and high taps that correspond to the
light states. Off, low, medium, and high lighting intensity requests
correspond to the low, medium, and high states of the plurality of
lights. AC power is switched between the transformer taps in response to
a request for an increase in lighting intensity. Power is sequentially
applied to the taps by supplying the power to the low tap for a first
predetermined time interval before supplying the power to the medium tap.