Altitudes are spoken digit by digit with the magnitude words (thousand, hundred) placed after the appropriate digits, to keep transmissions unambiguous. For an altitude like 17,900, you’d say “one seven thousand niner hundred.” Each digit is stated: 1, then 7, followed by “thousand” to mark the thousands group, then 9 is spoken as “niner” to avoid confusion with other digits, and finally “hundred” after the 9 to indicate the hundreds place. Any trailing zeros aren’t spoken. This approach minimizes mishearing in radio transmissions, whereas saying the number as a single word, spelling it out, or omitting digits could lead to mistakes.

Runway End Identifier Lights are designed to help pilots quickly identify the threshold and can be set to flash toward the approach area in either of two ways. They can be oriented unidirectionally, facing the approach path so the signal is directed at arriving aircraft, or they can be omnidirectional, flashing in all directions so they’re visible from a wider range of angles. The choice depends on the airport’s layout and approach geometry; some installations favor omnidirectional to ensure visibility from multiple approach angles, while others use unidirectional to concentrate the signal along the intended approach and reduce glare for other traffic. Because REILs can be configured in either orientation toward the approach area, both options are possible.

Capacity Potential is often organized around a mnemonic that groups several limiting factors. The first item you see is the LATE acronym, which stands for the key factors that influence capacity (Land Availability, Airspace Use, Topography, and elevation/environment). This mnemonic is placed first to introduce the category before the individual components are discussed. The remaining options correspond to these individual factors that come after the initial acronym. So the first item listed under Capacity Potential is the LATE mnemonic itself.

PAPI uses four lights to give a vertical position readout relative to the glide slope. Each light can be red or white, and the pattern tells you where you are relative to the ideal descent path. When you see two red and two white, that specific mix means you’re on the published glide path. The general rule is that more white lights indicate you’re above the glide path and need to descend toward it, while more red lights indicate you’re below the glide path and need to decrease descent or adjust to get back on track. Extreme all-white or all-red patterns would indicate you’re well above or well below the glide path, respectively.