but would a missing HF antenna coupler/LRU trigger a HF fail message? Is this a monitored device, or does it transmit an error message itself?
1. You can't fly with a componant missing
2. A faulty coupler sends discretes to the HF T/cvr which in turn reports to the CMC. An ACARS msg will then be sent.
The only msg;s ECAM will give you are
HF 1(2) Data Fault
HF 1(2) Emitting