TLOF is the meaning of grounding away from the area. The surface heliport should be provided with at least one grounded area (TLOF). The TLOF should be located within the final approach take-off zone or on the helicopter’s seat.
Airport Engineering: What is the TLOF lighting system?
What is the TLOF lighting system? The airport project will tell you today that the TLOF lighting system should be set up for the heliport used at night. However, when the runway type FATO coincides with the TLOF, it may not be set. Sidelights mainly illuminate the HLOF lighting system of the surface heliport, floodlighting, spaced point source array (ASPSL) or illuminating panel (LP) (when it is challenging to set sidelights or floodlighting, and FATO lamps are used) Or a variety of luminaire systems. The TLOF lighting system of an elevated heliport or helicopter landing platform shall include: sidelights, floodlighting and spaced point source arrays (ASPSL) or illuminating panel (LP) illumination.
For surface heliports used at night, to enhance surface signature signals, TLOF floodlighting or spaced point source array illumination or illuminator illumination should be provided.
The TLOF side light should be set along the TLOF edge or within a range of no more than 1.5m from the edge. When the TLOF is circular, the sidelights should be placed on several lines that provide the pilot with information about the offset; they can also be evenly spaced at appropriate intervals along the perimeter of the TLOF.
The TLOF sidelights should be evenly arranged. For surface heliports, the interval shall not be greater than 5 m; for elevated heliports and helicopter water platforms, the spacing shall not be higher than 3 m. At least four lights should be placed on each side (including the lights on each corner). When the TLOF is circular, and the lamp is evenly arranged along the circumference, at least 14 lamps should be provided.
The TLOF sidelights of an elevated heliport or a stationary helicopter landing should be installed so that the pilot cannot observe from below the TLOF elevation; the TLOF sidelights of the floating helicopter landing should be installed properly when the helicopter is at a level, the pilot cannot be from the TLFF Observed below the elevation.
The TLOF side light should be a fixed omnidirectional light that emits green light and should not exceed 25 cm in height. A recessed light should be used when the light above the surface would jeopardize helicopter operation or if the TLOF size is less than 1.0D. The light intensity distribution of the sidelight is as shown: