You were right. I could find the switch finally.
Maybe my remembrance from the BearStudios planes was not as good as thought.
Anyways, the plane indeed performed a cobra... actually, it even performed a full rotation then proceeded to gain altitude during its stall and spin inverted, typical FSX/P3D catastrophic physics engine as soon as you get out of the normal flight enveloppe. Not really the fault of FlyFreeSTD in that case.
Ah well, better than nothing. At least I could land it on the carrier this time.
Thanks for the tip.