AIM ¶ 2-1-9 — Airport Beacons
AIM 2-1-9 explains airport and heliport beacon colors, flash rates, and what a daytime beacon means for VFR pilots. Study guide for checkride prep.
In Plain English
Airport and heliport beacons are rotating or flashing lights that help pilots locate airfields at night. Their light is concentrated 1–10° above the horizon, but visible well above and below.
Flash rates:
- 24–30 per minute — airports, landmarks, Federal airway points
- 30–45 per minute — heliports
Color codes:
- White + Green — lighted land airport
- White + Yellow — lighted water airport
- Green, Yellow, White — lighted heliport
- Military airports — white + green, but with dual-peaked (two quick) white flashes
Why it matters: In Class B, C, D, or E surface areas, a beacon operating during daylight often means the ground visibility is less than 3 SM and/or the ceiling is below 1,000 ft — i.e., special VFR or IFR conditions, requiring ATC clearance to operate.
However, this is not regulatory. Many beacons run on photocells or timers, so pilots must not rely on the beacon alone to determine VFR vs. IFR. Proper preflight weather planning per 14 CFR 91.103 remains the pilot's responsibility.
AIM Source Text
FAA AIM ¶ 2-1-92-1-9. 2-1-9. Airport/Heliport Beacons
Airport and heliport beacons have a vertical light distribution to make them most effective from one to ten degrees above the horizon; however, they can be seen well above and below this peak spread. The beacon may be an omnidirectional capacitor-discharge device, or it may rotate at a constant speed which produces the visual effect of flashes at regular intervals. Flashes may be one or two colors alternately. The total number of flashes are: 24 to 30 per minute for beacons marking airports, landmarks, and points on Federal airways. 30 to 45 per minute for beacons marking heliports. The colors and color combinations of beacons are: White and Green- Lighted land airport. *Green alone- Lighted land airport. White and Yellow- Lighted water airport. *Yellow alone- Lighted water airport. Green, Yellow, and White- Lighted heliport. NOTE- *Green alone or yellow alone is used only in connection with a white-and-green or white-and-yellow beacon display, respectively. Military airport beacons flash alternately white and green, but are differentiated from civil beacons by dualpeaked (two quick) white flashes between the green flashes. In Class B, Class C, Class D and Class E surface areas, operation of the airport beacon during the hours of daylight often indicates that the ground visibility is less than 3 miles and/or the ceiling is less than 1,000 feet. ATC clearance in accordance with 14 CFR part 91 is required for landing, takeoff and flight in the traffic pattern. Pilots should not rely solely on the operation of the airport beacon to indicate if weather conditions are IFR or VFR. At some locations with operating control towers, ATC personnel turn the beacon on or off when controls are in the tower. At many airports the airport beacon is turned on by a photoelectric cell or time clocks and ATC personnel cannot control them. There is no regulatory requirement for daylight operation and it is the pilot's responsibility to comply with proper preflight planning as required by 14 CFR section 91.103.
Oral Exam Questions a DPE Might Ask
Q1What do the colors of an airport beacon tell you?
Per AIM 2-1-9: white and green indicates a lighted land airport, white and yellow a lighted water airport, and green/yellow/white a lighted heliport. Military airports flash white and green but with dual-peaked (two quick) white flashes between the green flashes.
Q2If you see an airport beacon operating during daylight in Class D airspace, what should that suggest to you?
Per AIM 2-1-9, a beacon operating during daylight in Class B, C, D, or E surface areas often indicates ground visibility is less than 3 miles and/or the ceiling is less than 1,000 feet, meaning an ATC clearance would be required for landing, takeoff, or pattern operations. However, pilots should not rely solely on the beacon to determine weather conditions.
Q3Is there a regulatory requirement for the airport beacon to be on during the day in IFR conditions?
No. Per AIM 2-1-9, there is no regulatory requirement for daylight beacon operation. Many beacons are controlled by photocells or timers rather than ATC, so it remains the pilot's responsibility to determine weather through proper preflight planning under 14 CFR 91.103.
Related Paragraphs in AIM Chapter 2