Hi Steve! Welcome aboard!
How was bomb aiming accomplished? Probably with a great deal of optimism...
You've probably seen this:
http://www.ctrl-c.liu.se/misc/ram/anatra-vk.htmlHowever, from a quick look at Gunston's "Osprey Encyclopedia of Russian Aircraft from 1875 to 1995", it seems that this might
not be exactly the aircraft you're referring to, even though it's probably very similar! In his brief description of the
Khioni No.4, Gunston refers to it as an "improved VKh", and then says, "not same aircraft as
'Anatra-Khioni No.4'". Trying to relate his descriptions of these aircraft, it seems that maybe the main difference was the engines; the Anatra-Khioni No.4 (also called the VKh Anadva) was powered by two 100 hp Gnome Monosoupape rotaries, while the Khioni No.4 had two 160 hp Salmson P9 watercooled radials. To add to the confusion (in my mind, at least), the Khioni No.4 was dimensionally the same as the VKh Anasalya, also called the Anadva-Salmson (two 140 hp Salmson M9 radials)! So, the lineage of these aircraft seems to have been:
Anatra-Khioni No.4/VKh Anadva > VKh Anasalya/Anadva-Salmson > Khioni No.4
<gasp!> Anyway, apparently all three versions had a crew of five - two pilots, one in each fuselage with dual controls, two rear gunners (one navigator/bombardier, one observer), and a third gunner perched in the upper nacelle or pulpit. This description is quoted from the section on the Anatra-Khioni No.4; perhaps it sheds some light on the bomb-aiming question?
I hope I've contributed at least a small amount on this topic; Heaven knows, this post now contains 100% of everything I know about these aircraft, so it was good for me, anyway! Maybe someone else will pop up with something better, I hope (there's probably a detailed, 500-page monograph dedicated to the Anatra/Khioni aircraft series, somewhere...)!
John