AFRU/PAALC
The Elecvis AFRU / PAALC unit has been designed to meet the requirements of
MOS139 and can configured to operate as either:
- Pilot Activated Airfield Lighting Control (PAALC) only.
- Automatic Frequency Response Unit (AFRU) only.
- Or both functions at the same time
Additional information
Pilot Activated Airfield Lighting Control
The Pilot Activated Airfield Lighting Control unit allows the pilot to turn on the airfield lighting using the communications radio in the aircraft.
When the radio is set to the PAALC frequency, the airfield lighting can be selected by 3 carrier transmissions ie. The pilot presses the microphone transmit button 3 times each press for approximately 1 second 3 times in 5 seconds. This will be recognised by the control unit as a light ‘ON’ command. When the lights are selected, they will remain on for a predetermined period set during the PAALC setup procedure of between 30 minutes and 90 minutes. The unit has been configured to be fail-safe so that failure of the equipment will result in the lights being turned on.
The PAALC will transmit a voice message of the status of the lights. The messages are stored on an SD card fitted to the main controller card and are in MP3 format.
These messages are:
- Aerodrome location
- NO runway lighting
- Runway lighting ON
- Lights 10 minutes remaining
- BEEP
- PAPI lights ON
Automatic Frequency Response Unit
When configured as an AFRU, the equipment will monitor the selected frequency for transmissions. An aircraft making a transmission of the aircrafts identification and location when entering an aerodrome locality will constitute a transmission greater than two seconds in length. The equipment on receiving this transmission will recognise it and respond on the Common Air Traffic Frequency (CTAF) with a transmission of the airport name e.g. Lilydale CTAF. This will confirm to the pilot that the radio is working and is on the correct frequency. It will also notify other aircraft in the area of the presence of another aircraft. The constant repeat transmission by the AFRU when aircraft may be engaged in a conversation would be a distraction so after one operation of the AFRU message, a timer is set for a period of 5 minutes so that subsequent transmissions that would trigger the AFRU will cause it to transmit a 300msec BEEP, hence the generic name for this type of equipment as BEEP BACK.
Operational Control
The operational controls are located on the front panel of the unit.
Power Switch
The main power switch is located in the centre of the front panel. It is an illuminated locking push button switch.
Human Machine Interface
All adjustments and operator controls of the PAALC/AFRU excluding the radio
adjustments are done using the touch screen display on the left side of the front
panel. This touch screen will illuminate at switch on. After several minutes without
touch inputs the screen will go blank to maximize back light life. The operator should
touch the screen to wake up the controller to check operation or make adjustments.
Extended Product Information
External Connections
All connections to the PAALC/AFRU are made on the rear panel.
These are;
- Mains power input 240VAC
- Antenna connection
- Thorn Legacy 15 pin “D” socket. This socket allows direct change over with older Thorn PAALC/AFRU equipment.
External Connections cont.
23 way 5.08mm plug terminal strip made up of
- 3 way input terminal
- 6 way input terminal
- 4 way Runway/IWI output control
- 8 way PAPI output control and Ambient light sensor
- 2 way 12volt auxiliary output
These connectors offer much easier field connection compared with the Thorn “D” connector via screw terminal plugs.
The fuse holder mounted on the rear panel protects the auxiliary power available at the terminal strip and on pins 1 &2 of the 15 D connector. The fuse is rated at 1amp and is a 205 style slow blow. This 12 volt supply is available for the user to power the inputs and outputs to the PAALC. Please refer to the drawings in the installation section of this document.
Touch Screen Controls
Start Up Screen
The start up screen is a summary of the current status of the PAALC , AFRU and Power.
This screen is currently showing the PAALC status.
Touch Screen Controls cont.
