Definition
Unlighted ground-based markers used as visual navigation aids, typically painted in distinctive patterns and colors so they can be seen and identified during daylight hours. Daybeacons mark airway routes, obstructions, or reference points and rely on natural light for visibility rather than illumination.
Plain English
Painted markers on the ground that pilots can spot during the day to help them know where they are or what to avoid. They have no lights, so they only work when there is enough daylight to see them.
Context Anchor
Pilots may see daybeacons mentioned when using visual references near waterways, coasts, or other marked navigation areas.
Derivation
Combines 'day' (the period of daylight) with 'beacon' (from Old English 'beacn,' meaning a sign or signal). The name reflects the fact that these markers signal information visually but only when daylight makes them visible.
Why Pilots Care
A pilot relying on a daybeacon must have enough daylight to see it. At night or in poor visibility, the marker effectively disappears, so flight planning must account for whether the visual reference will actually be usable.
Intuition Check
Do not assume a daybeacon is a light. If it is a daybeacon, its main purpose is daytime identification by appearance, not nighttime lighting.
Example Sentence 1
The sectional chart showed a daybeacon on the ridge, which the pilot used to confirm his position during the cross-country flight.
Example Sentence 2
Sectional charts show daybeacons with specific symbols so pilots can identify them in daylight.