FAA L-804 elevated runway guard lights (ERGL) consists of 2 unidirectional light sources that are 8 inch (203.2 mm) circles spaced 15 inches (381 mm) center-to-center. They operate in the same horizontal plane and must illuminate alternately at 45-50 flashes per minute over all specified brightness levels.
The fixture and/or the mounting system permits vertical adjustment of the light beam from 0° to +20° above the horizontal. The adjustment mechanism must detent in a minimum of 1-degree increments and must be able to lock in place to hold the desired vertical setting.
Using mounting equipment and a tether, install the L-804 securely to ensure that jet blast does not turn it horizontally, vertically or blow it onto a neighboring runway or taxiway.
Monitoring FAA L-804 runway guard lights is mandatory. Monitoring must detect lamp failure, flash failure and failure of the monitoring device.
For full specifications, please see FAA AC 150/5345-46E Specification for Runway and Taxiway Light Fixtures.