Spline Drive the Bell 360 looks exactly like the Boeing-Sikorsky RAH-66, very different from the S-67. It had GE T-58-5 engines and the NR could be controlled thru a limited range.Now, the Sikorsky S-97 Raider and Defiant have a broader capability in that area, necessitated by the increased speed capability. Running a rotor up near free stream Mach one creates a real noise issue. We did run a short test program one time,at the request of the Army,to evaluate the UH-60 up to a free stream Mtip of 1.0,and the rotor was stable at that condition. Was not a stealthy audible situation however.
Last edited by JohnDixson; 28th Feb 2020 at 20:56.
Reason: Correct an autocorrect.