A320 static inverter / ADIRS
 

Technical question about the A320 electrical system -- I want to confirm exact interaction between ADIRS / static inverter.

LOW SPEED WARNING 2 is a discrete output from ADIRS 1 which is false when the airspeed is lower than 50 knots; true when the airspeed is greater. It's fed into the relay 7XB which controls the static inverter operation

So my question is what happens if ADIRS 1 is not powered, turned off, or faulty? What happens if the airspeed parameter is NCD or invalid?

It seems odd that a vital component such as the static inverter would depend entirely on ADIRS1 without redundancy. The FCOM does not mention the static inverter as being INOP when the ADIRS airspeed parameter is NCD or invalid; or when ADIRS1 is unpowered or turned off.

Therefore, I'd have to guess that this is a fail-safe and "LOW SPEED WARNING 2" will be true unless the ADIRS is working and shows a speed of less than 50 knots. But I can't tell for sure from the ASM or AMM manuals. Any ideas?