Very cool animation

[Kwyjibo]

This is awesome.. VERY helpful for those who are visual learners, and super interesting for those that already know.

https://www.youtube.com/watch?v=u1lU64CG8p8

K./

[Old Mate]

I watched this… It states that the Advancing blade flaps down?
What am I missing??

[UnObvious]

I watched this… It states that the Advancing blade flaps down?
What am I missing??

Maybe they made a mistake?

Pretty solid video otherwise from the brief glimpses I got.

[Gunga Din]

Old Mate,
In forward flight, the disc is tilted forward to get the lift vectors to pull you forward. The advancing blade is flapping down, the retreating blade is flapping up, and away you go - all caused by the pilot poking the stick forward, and the swash plate making the changes in pitch angles.

Some people get stuck on the "flapping to equality" property, with the advancing blade flapping up.
That only happens if the cyclic is held steady (fixed) and a puff of wind comes from some direction - the disc will flap away from the relative wind. If in the hover, the chopper will start to fly away from the puff of wind, until the new direction brings the wind at the disc from the new direction - it flaps away from that, and sends you back again, but faster, because of the pendulosity of the fuselage. This back-and-forth will go for 3 or 4 cycles until the aircraft crashes. OR... until the pilot uses the cyclic.

It should be under "Stick fixed dynamic instability" in your book.

[Old Mate]

Cheers Gunga Din

I reckon I was getting confused by associating or comparing the above scenario with the effects of a Semirigid Rotor Stall…