At 18th June, 2021, we get the order confirmed - 250pcs of Lighting of unserviceable areas , for the Chengdu Tianfu International Airport.

Where a temporarily unserviceable area exists, it may be marked with fixed-red lights. These lights should mark the most  potentially dangerous extremities of the area. A minimum of four such lights should be used, except where the area is  triangular in shape where a minimum of three lights may be employed. 

The number of lights should be increased when the  area is large or of unusual configuration. At least one light should be installed for each 7.5 m of peripheral distance of the  area. If the lights are directional, they should be orientated so that as far as possible their beams are aligned in the direction  from which aircraft or vehicles will approach. 

Where aircraft or vehicles will normally approach from several directions,  consideration should be given to adding extra lights or using omnidirectional lights to show the area from these directions.  Unserviceable area lights should be frangible. Their height should be sufficiently low to preserve clearance for propellers and for engine pods of jet aircraft.