扭心

niǔ xīn kào jìn qián yuán de yè piàn bǐ niǔ xīn kào hòu de gèng yì qǐ chàn

扭心靠近前缘的叶片比扭心靠后的更易起颤。

The blade with the forward centre of torsion is less stable than the blade with the backward one.