Chinook low flyby vid doing the rounds on Facebook......

[fdr]

Originally Posted by 4468

”variation of the disk from the offset comes from flap back, which is speed dependent”?

So why does the chinnie have a level fuselage attitude throughout the speed range then, and how does ‘positive stick gradient’ work? (Both disks will tend to flap back at different rates and create differing translational lifts won’t they?)

I may look once again at the video, however even if it is a ‘deep fake’ I didn’t see anything wrong with either the orientation or rotation of the blades.

Good point!

"Differential Collective Pitch Longitudinal control is achieved by differential collective pitch (DCP); moving the cyclic stick forward decreases the pitch of the forward rotor and increases that of the aft rotor and vice versa. A differential airspeed hold (DASH) system ensures that a positive stick gradient is maintained throughout the speed range. Longitudinal cyclic trim is incorporated to enable the aircraft to be flown throughout the speed range in a substantially level attitude, thereby reducing drag and stress on the rotor shafts".