If FPV is not reliable and GPS altitude information is not available (no means to ensure level flight):
Adjust pitch and thrust according to table, and wait for speed stabilization. Expect a significant stabilization time and important altitude variations.
TROUBLE SHOOTING AND FAULT ISOLATION
When one indication differs from the others, flight crews may be tempted to reject the outlier information. They should be aware, however, that in very extreme circumstances, it may happen that two, or even all three ADRs may provide identical and erroneous data.
BEWARE OF INSTINCTIVELY REJECTING AN OUTLIER ADR
Once the affected ADR has (or have) been positively identified, it (they) should be switched OFF. This will trigger the corresponding ECAM warnings and associated drills, which should be followed to address all the consequences on the various aircraft systems.
In the extreme case where the affected ADR(s) cannot be identified and all speed indications remain unreliable, 2 ADRs should be selected OFF to prevent the flight control laws from using two coherent but unreliable ADR data. One must be kept ON to keep the stall warning protection. If at least one ADR remains reliable, the flight crew will use it (after having confirmed its validity), and so, will stop the application of the ADR CHECK PROC / UNRELIABLE SPEED INDICATION PROC.
PART 3: FLYING WITHOUT ANY SPEED REFERENCE
When the trouble shooting procedure did not permit to identify at least one correct indication, this part of the procedure gives pitch/thrust reference to fly the aircraft safely, in all flight phases, down to landing.
The flight crew may enter directly this part if he knows already that no speed information is reliable (for instance in case of dual pitot heating failure, plus an ADR failure), or if level off for trouble shooting is not convenient from an operational point of view, for instance in descent, close to destination.
When flying the aircraft with unreliable speed and/or altitude indications, it is recommended to change only one flying parameter at a time i.e. speed, altitude or configuration. For this reason, a wide pattern and a stabilized approach are recommended.
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