Aircraft Digital Control System (ADCS)

Question 1

The ADCS uses which 5 subsystems to control the aircraft.

Answer 1

Dual UARB network
Dedicated links
RCM
Fault tolerant components
Fault tolerant software

Question 2

What is the dual UARB network?

Answer 2

It is a redundant system that connects the RCM to the fault tolerant components

Question 3

UARB A and B are independent asynchronous serial buses, and data is transmitted in ______ format.

Answer 3

RS-422

Question 4

Which components are on only 1 bus of the dual UARB network?

Answer 4

1 batt junction box and both PPDMs are on UARB A
One batt junction box on UARB B
Vote processor 1 (located w/in RCM) on UARB A
Vote processor 2 (located w/in RCM) on UARB B

Question 5

What is the function in dedicated links?

Answer 5

to interface nonessential equipment with the RCM

Question 6

What are examples of items on dedicated links?

Answer 6

nav sensors, attitude sensors, transponder, sensor payloads

Question 7

What is considered the heart of the ADCS and what are its 5 functions?

Answer 7

the Redundant Control Module (RCM)

1. triplex processing
2. uplink command receipt, processing, and distribution
3. autopilot command generation and distribution
4. downlink telemetry data receipt, processing and distribution
5. video data receipt processing and distribution

Question 8

How many Flight Computer Assemblies (FCAs) are incorporated into the RCM and what is their function.

Answer 8

3 FCAs.

• Single board computer capable of independently controlling the aircraft and receiving sensor data.
• Each FCA outputs an independent stream of data and receives flight data from its own set of attitude and navigation sensors.

Question 9

What component allow the FCAs to share sensor data and datalink information?

Answer 9

the Cross-Channel Data Link (CCDL)

Question 10

FCAs receive inputs from which 3 triple redundant sensors?

Answer 10

1. triple Embedded Gps/Ins (EGI) nav sensors
2. triplex attitude sensors
3. precision pressure transducers for airspeed and altitude

Question 11

Describe Mid Level Voting.

Answer 11

mid level voting is nothing more than selection of the middle value.

Question 12

What selects the FCA in command?

Answer 12

Vote processors

Question 13

Each FCA produces ____ identical command datastreams. ____ going to ______ and ______ sent to ______.

Answer 13

2. one going to Vote Processor 1
   other going to Vote Processor 2

Question 14

Define fault tolerant component.

Answer 14

A component that has a ‘smart unit’ capable to interfacing with both UARB A and UARB B.

Question 15

What is an example of a fault tolerant component?

Answer 15

aileron servos
flap servos
rudder servos
engine control servos
landing gear retract servos
brake servos
engine fuel interface unit
avionics bay input/output (I/O) expander (nose lens heater,         
    ice detector)
Wing I/O expanders (left and right, with interface strobe 
    power supplies)
fuel heater controllers
individual printed wiring assy in RCM

Question 16

When does mid level voting stop?

Answer 16

when 2 of 3 sensors have faults

Question 17

What menu path should the pilot use to manually select the FCA?

Answer 17

critical switches, redundant avionics, processor select

Question 18

Which VITs are associated with the ADCS?

Answer 18

VIT 54 = CCDL state
VIT 40-42 = FCA 1, 2, 3
VIT 62 = autopilot sensor status
VIT 63 = voted navigation sensor status