Wtt 1 (Radio Stuff)

Question 1

CSCG (communications system control group) consists of the following equipment:

Answer 1

1. Audio mgmt computer (AMC)
2. Operator control panel (OCP)
3. Radio control unit (RCU)
4. Communications system controller (CSC)
5. Relay assembly (RA)
6. Interconnect box (IB)

Question 2

Backup/failure modes for communication subsystems

Answer 2

1. Single mission computer failure (AMC operational, AC power available)
2. 1553 data bus failure (AMC operational, AC power available)
3. AMC or OCP failure (mission operational, AC Power available, no AMC/OCP)
4. Battery mode (electrical problem or prior to APU start, only DC battery power available)

Question 3

Single mission computer failure

Answer 3

• AMC ✅
• AC pwr ✅
• ONE mission computer ❌
• no impact on ICS or radio comms

Question 4

1553 data bus failure

Answer 4

• AMC ✅
• AC pwr ✅
• 1553B data bus ❌
• both mission computers (primary and backup) lose power or system loses 1553 data bus traffic with mission computers
• no impact to ICS
• AMC still operates normally but must be controlled through OCP and RCU
• CLEAR/SECURE coms only available via RCU
• CLEAR/SECURE, DF, & RELAY functions on OCP are lost (req 1553B data bus)

Question 5

AMC or OCP failure

Answer 5

• mission computers ✅
• AC pwr ✅

-AMC or OCP ❌

• after AMC reset
• loss of primary power to AMC
• aircraft transients
• loss of the OCP
• RAD1 hardwired to pilot station
• RAD2 hardwired to co-pilot station
• both controlled by RCU, PTT for coms
• ICS available to all stations

Question 6

Battery mode

Answer 6

• AC pwr ❌
• AMC ❌
• DC pwr ✅
• electrical problem or prior to APU start
• ONLY RAD1 available (hardwired to pilot, controlled by RCU and PTT)
• ICS PTT (is fixed volume) and available to pilots
• ICS available to aft stations

Question 7

AMC cooling fan power is

Answer 7

Provided through the 4-amp AMC CB.

If CB is pulled, AMC will report OVERTEMPERATURE condition….

if AMC CB remains pulled, AMC will overheat and be damaged

Question 8

During any aircraft power transients or internal AMC circuit/software anomalies

Answer 8

Normal functionality of AMC may be lost while AMC attempts a reset.

This can last approx 30 secs

Within 1 sec, backup ICS (CALL) and radio operation will be available

There may be several instances of momentary comm loss until AMC completely resets

Question 9

With loss of AMC functional o ty, if notmal computer command operations via

Answer 9

Keyset/CDU cannot reinstate communications with AMC, cycle the main (10A) AMC CB on the #1 DC primary bus