Well thanks for the anwsers, but I did this way:
Put a trigger that activates repeatedly with:
Cond:
pilot damage < 0.5
On act:
pilot setdamage 0.6; pilot sethit ["legs",1];
And a groupchat explaining that theres nothing they could do 'cuse his leg is shattered...
This way he´s always hurt, but alive.
This turn out to be a pretty simple and effective solution. I guess this will even work with the other two first aid modules synched.