Which cockpit indication is shown when the radar digital computer fails its built-in test?

Which cockpit indication is shown when the radar digital computer fails its built-in test?

• A. Standby
• B. Comp Down
• C. Fault
• D. BIT Fail

Answer: (B)

When the radar’s digital computer cannot pass its self-test, the system cannot operate normally, so the cockpit shows Comp Down. The built-in test is designed to verify the computer, its processor, memory, and interfaces; if the computer fails this test, it’s considered down and the crew is alerted with this specific indication. This is distinct from a standby condition (which would imply a backup mode rather than a failure), a generic fault warning, or a BIT Fail indication (which would point to the test itself having an error, not necessarily that the computer is down).

When the radar’s digital computer cannot pass its self-test, the system cannot operate normally, so the cockpit shows Comp Down. The built-in test is designed to verify the computer, its processor, memory, and interfaces; if the computer fails this test, it’s considered down and the crew is alerted with this specific indication.

This is distinct from a standby condition (which would imply a backup mode rather than a failure), a generic fault warning, or a BIT Fail indication (which would point to the test itself having an error, not necessarily that the computer is down).