Mi-2 bord 211, which is getting dangerously close to its airworthiness certificate, got a new set of blades today.
A lot of Mi-2s in Europe are receiving composite blades so there is a plentiful supply of used, but nearly new, metal blades. The blades put on 211 have very few hours on them.
At dusk, when the wind was at a minimum, we balanced the blades the old fashioned way. A long non-metal pole with a roll of paper in the end is brought to touch the rotor arc. Each blade tip has been marked with a different color of chalk and each leaves a mark on the paper. Examining the marks lets you figure out which blade is riding high or low. To our pleasant surprise, the new blades on 211 tracked absolutely true right out of the crate. This was confirmed by the pilots who said that it felt really smooth.
The pole has to be brought up to the rotor arc very carefully.