Just to know it is out there. I “stumbled” on it the other day while I was looking up the Aerosoft and FSLabs 320s. It is a simulator for personal computers, but with a price tag that challenges only the most resolute devotee of the aircraft, or otherwise real life initial trainee having lots of trouble getting to grips with the course, to hit the buy button (480.00 Swiss Francs!).
Still, it is a simulator, after all, this is MudSpike, and I have not seen it reported here. For those who want to have a look (and for the mouth to water, for those who love in depth Airbus), The FlightDeck A32X by Airlinetools…
Apparently it is completely stand alone, not an add on. There is no indication (or admission) I can see that it was derived from some other sim, so if someone spots anything along those lines, please say!
The A-320 family have (at present) ten listed in FCOM Memory Item Procedures, of which this is one. There are also Limitations, and finally, some OEB (Operational Engineering Bulletins). These are the “staple” of any Line or Proficiency check ride. You must know them when asked out of the blue.
This one is a particularly serious and potentially confusing failure, so any hastiness or immediate “logical” assumptions must be avoided. With the event actually happening, you will not immediately be able to determine which of the two is really the incorrect reading (even, three if you include the ISIS), so wantonly switching to the number three ADR, or asking PNF to start calling speeds is out of the question. The only verbal exchange at this point, upon detecting a speed discrepancy, is the mandatory call out “Unreliable Speed”, which tells the PNF to follow and support with the execution of the memory item.
What is to be done? Well, as it is a memory item, I will write it here as I would converse it with a check ride airman. Then we can look at the paper checklist…
First, we get rid of all automation and flight management guidance cues. That means, the Autopilot goes OFF, as well as the Flight Directors, and the Auto Thrust. Immediately after that, we must revert to attitude and power flying, to accomplish the objective of exactly what you mentioned up above (not exceed VFEs). These come in three flavors. If you are just rotating or going around when the failure occurs, and have not yet reached the thrust reduction altitude, you advance the thrust levers to TOGA and pitch to 15° up. Once above the thrust reduction altitude, you have two scenarios, but both of them require you to retard the thrust levers to CLB detent. The difference is in what altitude you are at, with regards to the pitch you would set. If you are below 10,000 ft, you set 10° pitch, and above 10,000 ft, you would set 5°. Flaps you would leave as they are, unless you have full flaps set, in which case you would ask for retraction to configuration 3. Finally, check speed brakes and landing gear retracted. Your object here, now, is to get to a safe altitude to level off and ask for the paper checklist from the QRH. Those are the memory items complete, IIRC.
There are some tables in the QRH paper checklist, after the boxed memory item, which help you determine what power setting and pitch will give you a level flight path to continue evaluating the failure. I will take some snaps now, and let us see how I did…
Now, @Hangar200, as an ex-mechanical engineer myself, I understand your temptation completely to go into this with some numbers. A blocked pitot does not really freeze the indication; it makes the air speed indicator behave like an aneroid barometer (say, an altimeter), so to speak, indicating higher speeds from the initial “frozen” value as altitude increases. It is totally possible for us to sit here with a couple of formulae for dynamic pressure and compressibility and draw up a table of what the ASI tape should read as altitude increases. But it is not practical and rather pointless operationally, charged with much ambiguity in an already uncertain, undetermined situation. We could do it for an fun exercise, though, LOL!
More relevant to Airbus, however, Flight AF447, which is almost always a subject of discussion during recurrent ground school. I reserve specific comments regarding, but as a result, the Unreliable Speed procedure is one of those that is regularly revisited, and practiced in simulator.