When cleared to land, which visual cue indicates that you are off course?

The visual cue that indicates you are off course when cleared to land is red lights on the runway. In aviation, the standard for runway approach lighting systems includes a combination of red and white lights. Specifically, if you see more red lights than white lights, it indicates that you are low on the glide slope and need to climb to get back on the correct approach path. This is crucial for maintaining a safe approach and landing.

The white lights down the center of the runway primarily signify that you are aligned correctly with the runway and are on the proper glide slope. If you were seeing these exclusively and not red lights, it would not imply that you are off course.

Flashing runway lights are generally used to signal attention or indicate a temporary condition and do not directly relate to your position in the approach. Similarly, green lights along the perimeter of the runway designate the beginning of the runway and are not an indication of whether you are on or off course during your approach.

Thus, observing red lights indicates that corrective action is necessary to ensure a safe landing.