What does the phrase "Red over white, I'm all right" help pilots remember?

The phrase "Red over white, I'm all right" is a mnemonic that helps pilots remember the visual cues provided by a VASI (Visual Approach Slope Indicator) system during their approach to landing. When a pilot sees red lights over white lights, it indicates that they are on the correct glide slope and at the proper descent angle toward the runway. This visual information is crucial for ensuring a safe approach, as it helps maintain the appropriate descent path to avoid being too high or too low during landing.

In the context of using a VASI system, understanding this phrase allows pilots to make quick decisions and adjustments during their approach based on the light indications. Other options, such as the proper ascent path or cruising altitude, do not relate to the specific guidance provided by the VASI lights, making them less relevant in this scenario.