[Kwarde]

No need to forward+public that.
You can simply use stock. And you won't need to make two variables o_O. Here is it again, and a bit 'better' (not using variables is better. I'm too lazy to explain it now. Someone's made a tutorial. I think it was ****** but I can't remember right now)

pawn Код:

stock IsPlayerInReconPlane(playerid)
{
    if(GetVehicleModel(GetPlayerVehicleID(playerid)) == 553)
    {
        LimitPlayerMarkerRadius(3000.0);
        ShowPlayerMarkers(true);
        SendClientMessage(playerid, WHITE, "You are in a SAMC Recon Plane.");
        return 1;
    }
    return 0;
}