Originally Posted by
CONF iture
How misinformed can you be, and I even cannot feel the slightest doubt in your voice.
Let me have a serious doubt PJ2 said anything like it, but he will confirm if he did …
DozyWannabe, you’re not a pilot and don’t pretend to be one, and nothing wrong with that, but PLEASE, maybe you should refrain talking as if you were the Experienced guy around.
Ahem...
Originally Posted by DozyWannabe
Speaking of which, I wanted to double-check something with you. Am I right in thinking that in ALT 2 (aka "NO PROT") with airspeed data gone, that the FCU (or A330 equivalent) autotrim will basically use the THS to meet pilot demands when the limits of the elevators are exceeded?
And the reply...
Originally Posted by PJ2
Regarding your question, yes, to put it simply, the THS will follow the sidestick orders in Alt 2 Law.
The elevators are short term pitch control, the THS long-term, providing the elevators with full authority throughout their range. The THS changes position as a result of inputs from the FCMC, (Fuel Control Monitoring Computer), LGCIU, (Landing Gear Control and Interface Unit), the SFCC, (Slat Flap Control Computer which input data to the in-command FMGEC, (in this case the #2, as #2 AFS was engaged). The FMGEC sums control command inputs including those from the sidesticks and the FCU (Flight Control Unit on the A330), and sends position orders to the FCPCs & FCSCs which in turn provide a "Delta QT" order for the THS, Delta Q for the elevators, and so on.
The AF 447 THS was simply doing as it was ordered within the limits of aircraft attitude in the FMGECs. The THS disengages under a number of important circumstances including an AoA of >30deg/< -10 but pilot authority is retained up to these limits and, most importantly.
This point has been completely missed by many (though not all, especially the old guys!), manual operation of the THS is a simple matter of rolling the trim wheel forward to return the setting from 13deg to 3 or whatever was needed until the system could re-engage.
So CONF, if you don't mind, maybe a little less of the emphatic declarative in your tone (and maybe, you know, one day accepting that Asseline was wrong and Jacquet *did* go mad trying to defend the indefensible) would be in order?
@rudderrudderrat - If the rudder was the only way to correct roll (and in this case we don't even know if the aircraft was having lateral stability issues or not - it's not in either the early interim report or the note), then there's a manual dial and switch on the centre console.