Fregon Airstrip

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CONTROL CUBICLE

The control cubicle houses the control functions, Pilot Actuated Airport Lighting Control (PAALC) and the mains isolating transformer.

There are two methods of control available, either manual control or by the PAALC equipment. The PAALC operates at a single frequency and allows a pilot to operate the airport lighting using the VHF radio in the cockpit.

The frequency allocated for Fregon is 119.6MHz.

PAALC turns on the airport lights (runway, taxiway, windsock and floodlighting if installed) for a set period of between twenty and ninety minutes after a suitably coded radio frequency signal has been received. In Australia this time is usually preset to 60 minutes, as is the case at Fregon. Having turned on the lights, the equipment can be reactivated at any time during the set period. If no other correctly coded transmission has been received in that period, the timing sequence continues normally. Ten minutes before the end of the set period, the equipment starts switching the I.W.I. on and off 50 times a minute, as a ten-minute-turn-off-lights (TMTOL) warning. The TMTOL warns pilots that less than ten minutes remain before the airport lights will switch off. If no reactivation is made during the flashing time, all lights will switch off at the end of the period; otherwise the equipment will recycle and the lights will remain on.

A monitor module, together with a Test Oscillator in the Receiver module, allows a functional check to be made without external test equipment. This check covers all but the aerial, its cable and connection to the receiver. By following through a straightforward check sheet a non-technical person can generally identify which module is at fault. Faulty modules are replaced via a changeover service operated by DNT Europhane.

The control equipment is fail-safe in that in the event of a failure or interruption to the supply to the equipment or within the equipment, the airport lights will turn on. The lights will remain on for the set period after the restoration of the power supply.

The equipment is constructed as a series of modules which plug into an aluminium chassis. The Power Supply module and the VHF Receiver module are fully enclosed.

MAINTENANCE

l. On a weekly basis check the runway,threshold, taxiway lighting and Illuminated Wind Indicator. Replace unserviceable lamps.
2. On a yearly basis the following inspections are required. The interval between inspection in some cases may need to be six monthly, depending on local conditions.

LIGHT FITTING

Lamp - inspect and replace if burnt out or unduly blackened.
Glass Lens - inspect and clean. Replace if unduly chipped or cracked.
Levelling - check that fitting is level.

CONTROL CUBICLE

Check termination and wiring.
Check operation of cubicle - Manual and PAALC control.
Check the PAALC cycle time i.e. total ON-TIME.
Check the TMTOL of PAALC i.e. the length of time IWI flashes.
Check that the PAALC operates after mains failure.
Take a Megger Test of the insulation resistance of the Airport lighting primary circuit.
Check the field current reading.