Sikorsky's Experimental Aircraft
 

Saw this today.....interesting concepts but I am sure there are some issues to be worked through with such new concepts.


https://www.defensenews.com/land/202...t-public-demo/

The bait is out there, waiting for Sultan to leap in........

AC,

The article says it all. Neither design exhibited performance exceeding that of traditional helicopters which are cheaper and do not have the risk of the rotors colliding in aggressive maneuvers.

Dang....you can't keep the pin fish off the line long enough to land a trophy!

Cool videos - thanks for the post!

https://books.google.com/books?id=Fz...page&q&f=false

The only two vids I saw were Raider and Defiant.
Was there a SARA video as well?
FWIW, the Army had an actual UH-60 Blackhawk flying about using a remote control kit a few years ago.
Part of an R&D effort, but I don't know what became of it.

Sans....I was at West Palm Beach back when the ABC was flying.....that is where I first met Nick Lappos who was one of the Test Pilots.....that was back in 1979 or so.

If Sultan can claim the V-22 as new concepts despite all that went before it clear back to the 1950's.....I would suggest you can give me pass on this.

The ABC did not have a pusher prop.....that came from Piasecki which had that on a Blackhawk airframe a few years back.

It did have a couple of J60's.

Externally mounted and independent of the Transmission system too.....unlike the Pusher Prop.

Yes. They were left over from the S-61F (NH-3A) and were available. There was talk at the time that a prop would be desirable.

Notice in that PopSci article the illustration on page 70. XH-59B was supposed to have that ducted pusher, dreamed up all the way back in the late 1960s. After seeing the A model in action, the Army was uninterested in pursuing the concept further.

As far as the rigid rotor coax in general? The Hiller boys were way ahead of the curve in '45 (and apparently the X2 moniker as well)

http://www.aerofiles.com/hiller-x2235.jpg

Progress in the helicopter world is an interesting tale.

Think back to the Cessna single piston engine "Sky Hook" that was certified for IFR flight by the FAA a very long time ago... and where are we today on that?


Collect Air

Sikorsky can successfully argue that they flew a pusher tail-prop long before the Piasecki pusher. Recall the Roto-Prop testing on an S-61A in the mid 1960’s. Pics are in the SA archives.

Deleted, entered in error

https://cimg8.ibsrv.net/gimg/pprune....e15bb1430b.jpg

More details available at: https://www.sikorskyarchives.com/S-66%20AAFSS.php

Or Lockheed with the AH56 Cheyenne.

PDR

Thanks,rrekn,that pic reminded of something: one of the plans for the S-67 future,was to reinstall the fenestron tail we had already flown on it,but adding both a controllable rudder and a declutch mechanism for the fenestron rotor.

Historical note re the S-67 fenestron. The highest speed I see quoted for the 67 happened by coincicidence with the fenestron test program.The high speed limit was 200 Kias but on that day ( it was winter, cold and somewhat turbulent due to a just passed cold front ) we did it around 6000 ft and were watching the tip path closely, remembering that the standard rotor on the S-61F had gone unstable at a Mtip of .94 ( freestream ). That day the 200 KIAS resulted in a freestream Mtip of .96 and without any rotor stability issue.

I've always liked the S-67 and I think Bell did a good job hitting it with the "shrink ray" with the Model 360... not an unreasonable configuration for the mission. Did the S-67 have the ability to slow down the rotor rpm to control tip speed? Or at ~200 knots, was it at the limits of the system's ability to do so?

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.