Quoting Capn Bloggs
Actually, the amount of stick you need to generate that rate of climb isn't a lot: as a rule of thumb for my TCAS responses (passed on down by an old hand) I use: 1° of pitch change results in about your Mach number in Rate of Climb: If you're doing .8 and you pull 1° of pitch, your ROC will be around 800ft/min. I haven't actually used 10° on a TCAS RA
, but lesser changes indicate those numbers are pretty close. It's not difficult (and certainly not severe) to pull 10°: there's your 8000ft/min climb rate... for a short time at least.
You're measuring the stick movement by the effect of pitch on the plane - rather than the position of the control surface.
Having never flown anything heavy, my assumption is that to reach an 800FPM climb (FACs not-withstanding), you would pull back on the stick far enough so that your target ROC was reached in perhaps 5 or 10 seconds. Then you would relax the stick a bit to hold that ROC.
However, if the control surface (the elevator) jammed in place you would find yourself at 800FPM in say 7 seconds, 1600FPM in 15 seconds, 2400FPM in 24 seconds, and only a your airspeed would keep you from completing an inside loop.
If that rate of climb isn't enough to build up to what was seen in RADAR, then perhaps the pilot was merely trying to maintain altitude in a sudden down-draft. He may have been very aggressive in trying to restore altitude and attempted to cause that 1 degree pitch up in much less than 7 seconds.
The point is that a control surface movement applied for 5 seconds can be very normal - but when jammed in place for tens of seconds can be very severe.
Also, there is no deicing provided on the tail of the A320.