He 111 instrument
 

I the He 111 there is an instrument with one centered green dot, changing on approach of an airfield to two green dots:





http://i287.photobucket.com/albums/l...tooo/he111.jpg




anyone who can explain how this instrument is working properly? any tutorial on this?

If it were a indicator with 2 needles, one vertical and one horizontal, the lower left point would indicate the crossing point of the needles and the center point is the center point :-D.
The actual position of the points indicate that your approach is to the right of the centerline of the runway and that you are above the glide path.
If one holds the points one ove the other one is on a perfect blind approach to the landing.

thanks m8