Flashcards in Communication Control Systems (CCS) Deck (23)
What are the LRU's of the SCCS?
Digital Audio Mixing Unit (DAMU)
Communications Control Panel (CCP) x 3
Headset Electronic Unit (HEU) x 5
Signal Conversion Interface Unit (SCIU) x2
Signal Conversion and Switch Matrix (SCMU)
Emergency Intercom Radio Amplifier (EIRA)
Where are the HEU fitted?
Left hand side No 1 (Co Pilot) + 3 (Snr PAX)
Right hand side No 2 (Pilot)
Rear AV Bay
No 4 (TETRA)
No 5 (ARC 231)
Why has each HEU got 2 channels?
It allows multiple users of the same HEU and CCP to be allocated to different nets.
Where is the DAMU?
Rear avionics bay, centre shelf, slot 4.
What is the purpose of the DAMU?
It is the central data controller for the SCCS and controls all selected intercom and radio functionality. (The brain)
How are communications between the DAMU and other LRU's transmitted?
Digitally via dual redundant fibre-optic cables which mitigate TEMPEST risk and reduce aircraft weight.
What is the purpose of the SSCIU?
Interfaces audio to and from encryption devices and includes an external connector for the telebrief.
What is the purpose of the CSCIU?
Provides audio and interfaces for the V/UHF + HF radios.
Receives audio from :
Where are the SCIU powered from?
SSCIU - Dual power DC Gen BB no 1 + 2
CSCIU - Dual power DC engine start BB no 1 + 2
What is the purpose of the SCMU?
Controls the allocation of the three KY-100.
How is the SCMU controlled?
Entirely by the DAMU but has a 1553b Databus connection for sending status information to the CDNU.
What is the purpose of the EIRA?
provides back up comms system in event of SCCS failure.
How is the EIRA powered?
DC Essential BB 1 + 2.
Where is the EIRA located?
Cabin roof (right side)
In the event of a failure what happens? (EIRA)
Pilot/co Pilot are automatically connected to a dedicated clear intercom net.
Assigned V/UHF 2 + 1 respectively.
What is the purpose of HEU 4+5?
To convert fibre optic DAMU data into analogue audio for BOWMAN
What happens when the PTT/CALL switch is put in the CALL position?
It disregards the NET switch and connects all 3 NETS together.
How long can you be in CALL before the switch times its self out?
What is the first pressure on the 2 position trigger on the collective used for?
Mutes all the radios and only allows intercoms to be heard.
What is the second pressure on the two position trigger on the collective used for?
CWS audio cancel.
What is the function of the TONE switch on the CCP?
Transmits a 1Khz tone for morse code in the event of a mic failure.
How do you transmit through TELEBRIEF?
By holding the TB button on the CCP whilst the telebrief cable is attached to the aircraft.