SFLS description

 

Examples

 

A Sequence Flashing Light System (SFLS) can be designed on different ways, according to ICAO recommendations :

 

 

 

 

SFLS category I without REILS
30 flashes works in a sequence of 14 ms and a repetition period of 0,5 s.

 

 

SFLS category I with REILS
This is the same configuration, apart from the adjonction of a REILS on the runway threshold.

 

 

SFLS category II or III without REILS
20 flashes work in a sequence of 14 ms and a repetition period of 0,5 s.

 

 

SFLS category II or III with REILS
This is also the same configuration with the adjonction of a REILS on the runway threshold.

 

 

REILS only
The characteristic of a REILS is that the 2 flashes work exactly together and, when a faulty lamp occurs, the other one stops working for safety reasons.

 

 

ODALS
5 flashes plus a REILS work in a sequence of 267 ms (or 67 ms) and a repetition period of 2 s. (or 1 s.)

 

 

Heliport approach
4 flashes works in a sequence of 267 ms and a repetition period of 2 s.