Like the Mi-24 balancing act shown in a previous post,
the Cold War Air Museum, Mi-2 got its turn with the electronic balancing machine. As the blade tracking is adjusted to perfection (or as near as possible), the plane view of the rotor disk (as seen from the side) tends to get smaller or disapper completly. Johnny studies the readouts from the sensors attached to the tailboom.
Before the run, the sensors were attached to the tail.
Other runs were made with other sensor placements. Here sensors are being placed by the transmission while the usual crew of "supervisors" discusses the operation.
After each run, the pilots, techs and mechs talk things over.