Thx a lot everyone !
@ Muffins, you're right, Birth anim was wrong...
i'm sorry, i made a stupid mistake by thinking that, because there is only SW anim in paradrop, the anim didn't needed the other directions (which I erased AFTER

testing my unit ingame)... I uploaded a corrected birth anim and it works fine now.
@ aaglo
yes it as no directional data, I would have liked the circles to turn, to make a good movement anim, and perhaps an attack one, but my skills are really to low.
But it works fine in the game if used as immobile telepad...
It should have the following stats :
movement : 1
operationnal range : at least 1
defense : 1 (it's just a magical symbol on ground IMO, and giving it defense stat will make it possible to see its hitpoint, which is useful for telepad, each unit teleported to it costs 1 HP to the portal. You give extra HP to be able to teleport more than 2 units a turn on it ; telepad unit with 1 HP can no more be the target destination of teleportable units)
telepad range : at least 2 (because ingame range is the half chosen here)
NOT "go to" and "explore" Standard orders
at least "airdrop" and "telepad" Special actions
at least the "immobile" flag (though I put defaut.flc as movement anim if you want it to be movable).
But your idea of using it as helicopter make sense too, I just did not think about creating it.. in this case simply remove telepad abilities, add a transport capacity, and give it air missions, I suppose it would work too.