There's something that bothers me inherently, and just like the Hueys from Vietnam, 'only' having two blades. Doesn't seem enough, I mean, if despite your best planning, engineering -- whatever -- you lose one, you're like a twisty brick plummeting to the ground; and on the way down, it won't be any value shouting "That shouldn't have happened!!"

OK, first up, I accept the higher centre of gravity thing, if I have 4 blades, f'instance, but that's an engineering problem that can be fixed, ie. that's no reason.

There must be some other reason I can't have -- if in fact I actually can't -- have 4 or 6 or... isn't there an Aerospatiale chopper with 9??

Please tell me what I don't understand....

  • $\begingroup$ Welcome to Stack Exchange! This is a good question... $\endgroup$ Jan 25 '20 at 4:39
  • $\begingroup$ Actually the most efficient would be to have a single blade. Multiple blades are always working in the wake of the leading blade. $\endgroup$
    – Ron Beyer
    Jan 25 '20 at 4:40
  • 3
    $\begingroup$ See Why don't helicopters prefer shorter rotors with more blades? and Why are three-bladed helicopters relatively rare? Also, any rotor with one blade shot, would be extremely unstable and will also crash. $\endgroup$
    – ymb1
    Jan 25 '20 at 4:44
  • $\begingroup$ I should have said... I was actually thinking in the context of gyrocopters / gyroplanes. Yes, I can see how a blade would be working in the wake of the one ahead of it, but I'm going to assume (obviously can be wrong) that a 4-bladed configuration is sufficiently separated for that not to be a limiting factor... for gyrocopters. $\endgroup$ Jan 25 '20 at 4:55
  • 2
    $\begingroup$ Does this answer your question? Why are three-bladed helicopters relatively rare? $\endgroup$
    – dalearn
    Jan 25 '20 at 11:08