I just found about another very light helicopter build until war in Kharkiv and most likely used on front-line even if is not official in Ukrainian army probably as a spotter and light liaison.
АК1-3
http://www.airwar.ru/enc/uh/za6.html
https://www.facebook.com/aerocopter.ak1.3/
here destroyed helicopter on front-line
http://www.ukraviaforum.com/index.php/topic,1950.0.html
And here article about Russian conversion of that helicopter to UAV drone
https://defence-blog.com/russia-conv...er-into-drone/