The F4 and G4 tower types are over 1050′ tall but not more than 1400′ excluding any appurtenances and are lit by 8 L-864 red medium intensity beacons and 12 L-856 white high intensity beacons.
FAA AC 70/7460-1M
- Dual L-864/L-864 beacons include red, infrared and white LEDs.
- L-864 red/infrared beacons must flash in sync at 30 fpm.
- Infrared LED strings must be monitored, and an IR outage is a NOTAM-worthy event.
FAA AC 70/7460-1L
- L-864 beacons must flash in sync at 30 flashes per minute
- No L-810 marker lights are required
FAA AC 70/7460-1K, FAA AC 70/7460-1J and FAA AC 70/7460-1H
- L-864 beacons set to 20-40 flashes per minute
- 12 L-810 steady-burning marker lights
F4 Towers
- F towers have appurtenances greater than 40′ and 1 L-864/L-865 dual medium intesity beacon is required on top
G4 Towers
- G towers have no appurtenances greater than 40′ so no dual L-864/L-865 beacon is required
