This is a somewhat long post but I've been reading all the various threads related to AF, pilot skills etc ad nauseum without making very many comments. Something about this subject made me feel like posting so here goes.
No disrespect is intended toward the OP, I just feel compelled to comment in this instance because I have finally come to realize that there are actually pilots out there who believe that a single correct combination of thrust and pitch attitude can be appropriate under such widely variable circumstances as are encountered in any normal leg flown in a jet. I can hardly believe that anyone could think so. Not just due this thread but rather the overall impression I get from reading the aforementioned threads related to this subject.
I am not commenting on Airbus, Boeing or any other manufacturer but rather on how the UAS scenario should be perceived by pilots. I don't know much about what's contained in an A330 AFM but I do know that each airline around the world will be responsible for what's in their own training and crew manuals. I hope none of them consider a single pitch/thrust combo to be appropriate in all UAS scenarios and that latitude is still given to apply good airmanship in lieu of an over-simplified approach to a scenario requiring a knowledgeable and considered response.
The problem with creating a single pitch/thrust combination that all pilots flying a particular type should to revert to in the event of suspected or total failure of one or more airspeed indicating systems is that no single combination of thrust and pitch attitude will be appropriate for all circumstances under which an UAS scenario may occur. Obviously the combination of pitch/thrust required to clear terrain while maintaining a safe minimum airspeed during initial departure will be different compared to the pitch/thrust combo required during high altitude cruise where both high and low speed buffet margins must be respected. Any attempt to find one pitch/thrust combo to use in either scenario would be less than ideal to meet either circumstance at best and potentially disastrous at worst.
So rather than seeking a single unified pitch/thrust combination to revert to in the UAS case, it makes far more sense to revert to a pitch/thrust combo that will achieve an airspeed and vertical profile that's appropriate to the circumstances at hand. Even if one reverted to the pitch/thrust combo that one is accustomed to watching the A/P fly in that phase of a normal flight, they'd likely achieve a better outcome more often than if they followed this canned response of seeking a single fixed pitch/thrust combo under all circumstances.
In consideration of the above I can only conclude that it makes far more sense to consider the situation before selecting an appropriate pitch attitude and thrust setting should the IAS go blank or is suspected of being unreliable. In many circumstances the current pitch/thrust combo might be entirely sufficient and only need be maintained as is!
So in short:
If near the ground fly upward at high thrust, maintaining a pitch attitude which you know from experience will result in a safe airspeed plus a reasonable margin. Inform ATC of your situation and get to a safe altitude. After achieving a safe altitude, select a pitch/thrust combo that you know will result in level flight at a safe and comfortable airspeed then utilize all available resources to isolate the problem and come up with a plan to arrive safely back on the ground.
If at or near maximum altitude considering weight and temperature, don't do anything for a moment! Take a sip of your coffee or tea while you and your fellow crew consider the best plan of action. Consider whether a slight reduction in both pitch and thrust might be in order to descend towards an altitude where the high/low speed buffet margin will be greater or whether it might be better to remain above weather below. Would a course change be appropriate?
Now I've never had an actual total failure of an air data system in flight but a couple of instances of partial failure definitely inspired me to give the matter some thought long before the AF 447 affair. Even if nothing else good ever comes of that occurrence, at least the matters of basic attitude instrument flying skills and various system failure scenarios have come to the fore in various discussion forums and even the training organizations have been forced to look inward. Hopefully the pilot community will take the opportunity to re-assess their own capabilities and re-learn the most important truth of all: That regardless of the state of airlines, training and regulatory policies worldwide, it's your rear end up there and you are the last line of defense against another "unfortunate occurrence". Equip yourselves with all the knowledge and skill you can acquire and don't allow the grind of routine uneventful flights and ever more pervasive cockpit bureaucracy to dull your senses into a state of robotic complacency. Until the day when they actually fire you in favor of "autonomous aerial systems" BE A PILOT!
That is all...
westhawk