Comm/subsystems Backup/failure Mode

Question 1

Single Mission Computer failure

Answer 1

AMC √, AC Power √

No impact on ICS/radio comms

Question 2

1553 Data Bus failure

Answer 2

AMC √, AC Power √

Enabled if AMC is operating, but both MDs lost power (so maybe dual converter fail?)

No impact on ICS, though comms with MSN CMPTR lost, so AMC can only be controlled via OCP and RCU

Question 3

AMC/OCP failure

Answer 3

No AMC, AC Power √

RAD 1 hardwired to pilot station, RAD 2 hardwired to copilot station (RCU control only)

ICS CALL available to call stations

Question 4

Battery Mode

Answer 4

No AMC, No AC Power

Only RAD 1 avail. via pilot station & RCU control

ICS PTT (fixed volume) is avail, ICS is available to aft stations.

Question 5

The AMC cooling fan power

Answer 5

is provided through the 4-A AMC CB.

If the CB is pulled, the AMC will report an OVERTEMPRATURE condition.

If the AMC CB remains pulled, the AMC will overheat and damage with result.

Question 6

During any aircraft power transients or internal AMC circuit/software anomalies, normal functionality of the AMC:

Answer 6

may be lost while the AMC attempts a reset.

This situation can last up to approx. 30 sec.

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

There may be several instances of momentary comms loss until the AMC completes the reset.

Question 7

With loss of AMC functionality,

Answer 7

if normal computer command ops via keyset/CDU cannot reinitiate comms with the AMC, cycle the main (10A) AMC CB on the #1 Dc Pri Bus.