> There are therefore three speed information elaboration systems that function independently of each other. The probes known as “Captain” supply ADR 1, the “Fi

> There are therefore three speed information elaboration systems that function independently of each other. The probes known as “Captain” supply ADR 1, the “First Officer” probes supply ADR 2 and the “Standby” probes supply ADR 3. The standby instruments elaborate their speed and altitude information directly from the pneumatic inputs (“standby” probes), without this being processed by an ADM or ADR. The ISIS is a unique standby instrument integrating speed, altitude and attitude information. It uses the same static and total pressure sensors as ADR3. From the report on AF447 an Airbus A330. Again, much as I described.