Complicated and time-consuming circuit changes
An airport can only expand to a certain level before changes are needed on the runway and taxiways. Sometimes new regulations force the airport to change its infrastructure. Changes like this cause operational problems. Not only are they costly and time-consuming but the airport’s availability will be decreased and this can affect customer confidence.
Delays caused by new or additional stopbars
When trying to increase the safety of the airport, problems can occur. When adding a new or additional stopbar the airport often has to invest in new CCRs and cable. Certain sections of the airport have to be closed due to excavation and backfilling, which causes decreased availability.
Investigation of possibly critical alarms
Today a lot of airports cannot differentiate between a critical and a non-critical lamp failure. Instead they use the CCR, and get the percentage of functioning lights based on an equation. At most airports, two adjacent lights are not allowed to be broken, so how do you know whether that is the case if you only have the percentage of functioning lights? This means that maintenance personnel have to rush off to investigate the situation, which could result in airplanes put on hold and decreased availability.
ICAO compliant light segments?
Another effect of not knowing the operational status of light segments is not knowing if the airport is ICAO compliant. Are all light segments compliant with regulations; are there two adjacent lamp failures? If there are, the airport category must be downgraded leading to operational consequences.
Inability to know status of light segments
When changing CAT status the airport is not aware if all light segments are compliant until actually entering the status. What will the airport staff do if the lights are not compliant and they are not able to land the incoming aircraft? What are the consequences of being forced to direct the aircraft to another airport?
Segment defined by cable and CCR
Historically the airport infrastructure has been designed with few lamps per circuit. This results in more CCRs and more cable, leading to a risk for space problems in substations, higher investment cost, longer return on investment, no flexibility, not being prepared for future upgrades etc.
Current light fittings use CCR to control intensity
Today airfield lights are being intensity controlled by the CCR. Not only does this lead to large power consumption but also a large need for cable and CCRs, and higher investment costs.
Limitations of lamp function combinations (on circuits)
An effect of controlling light intensity by the CCR is that you cannot combine lamp functions. This is because different lamp functions can require different intensities under the same operating conditions.The result is complicated installations and upgrades, high costs and incompatibility.
