But when flying forward the air passing over the blade that is advancing to the front of the helicopter (and so into oncoming air) provides more lift than the one that is retreating to the back.

The concepts and frames of PC blade and its security management system are introduced in this paper, and a strategy mechanism is put forward to define PC blade security management system.

This article deals with the reasons for blade-pump's failure in hydraulic circuit and puts forward corresponding counter plot.