Airbus FBW Autothrust Question
 

You are in a steady state normal cruise at (say) FL350 with AP and ATHR engaged and in managed speed. You encounter a wind shift that causes the speed to start reducing. The ATHR tries to compensate for this by increasing thrust. Eventually the thrust is up to the current limit, but the speed is still decreasing and approaching VLS. If you now push the thrust levers up to the TOGA gate:
(A) Do you get any further increase in thrust?
(B) What would the FMA now be reading?

At altitude TOGA thrust isn't much higher than climb, the difference is almost negligible.
The FMA will show TOGA as thrust, but wouldn't change otherwise - go around mode is armed only with the flap lever out of zero.

I've "goosed" it by putting it in MCT for a few seconds. Seems to help when ATHR gets a little lazy.

Top Right corner of the E/WD is the Thrust Rating Mode and Thrust Limit Value.
Watch the Thrust Limit Value as you select MCT from CLB - it may increase a little.
As you select TOGA from MCT, the value - and the thrust - will remain the same. The Mode will change from MCT to TOGA but MCT is as good as it gets at altitude.

mcdhu

ATHR state would switch from engaged and active to just engaged. And would re-activate when THR CLB is re-set.

Raymond : If headwind is increasing, there is a very high chance that it will decrease all the more just after.
In high altitude cruise, wind can make you go from Valpha prot to MMO and the contrary in only a few seconds !
There is nothing ATHR can do about that.
Maybe a solution would be to maintain a speed as high as possible and protect yourself from overspeed with spoilers.

Or be ready to apply altitude corrections to help speed vary.
(In normal law, the flight control computers WILL apply altitude corrections if it comes to that)