Rotorheads A haven for helicopter professionals to discuss the things that affect them

S97 Raider

Old 7th Apr 2014, 17:09
  #41 (permalink)  
 
Join Date: Nov 2010
Location: Earth
Posts: 601
It was just a swag I came up with on a proverbial napkin some time ago, based on disc loading and FM, limited by rotor radius due to minumum hub spacing for high speed forward flight.

I have no doubt you could increase the GW and manufacture larger heavier rotors, however the requisite disc spacing increase sees exponentially diminishing returns in Vmax due to drag.

Also, consider the XH-59A/S-69 tipped the scales at 9,000 lbs and one of the primary goals of its unfunded successor XH-59B was a "significant weight reduction", which ended up eventually yielding a 5,300 lb X2 TD.
SansAnhedral is offline  
Old 7th Apr 2014, 19:50
  #42 (permalink)  
 
Join Date: Jul 2004
Location: Durham, NC USA
Posts: 350
I have to question the level or risk when proposing the S-97 Raider as a true competitor for the US Army’s AAS program. Having flown the XH-59A and viewed many of the X-2 videos it is apparent that at this point both aircraft have demonstrated only limited flight envelopes. Straight line speed was first and foremost in both programs. However, I believe that the XH-59A did perform limited maneuvers at altitudes up to 20,000 ft MSL. I am sure that AAS program maneuverability and agility requirements with be very demanding.
Jack Carson is offline  
Old 7th Apr 2014, 19:58
  #43 (permalink)  
 
Join Date: Aug 2009
Location: Texas
Age: 60
Posts: 5,337
I am sure that AAS program maneuverability and agility requirements with be very demanding.
So too were the similar requirements for Comanche. Oops, look what happened there!
Lonewolf_50 is offline  
Old 7th Apr 2014, 20:13
  #44 (permalink)  
 
Join Date: Mar 2005
Location: Poplar Grove, IL, USA
Age: 52
Posts: 834
I like the source that says the scaling is limited. Any company exec is always the go-to source for technical information.
Bryan
IFMU is offline  
Old 8th Apr 2014, 01:00
  #45 (permalink)  
 
Join Date: Oct 2007
Location: USA
Posts: 147
Thanks Sans, as with everything helicopter it's a trade off between weight and ___________. I imagine that if they think they can scale this up to something Blackhawk sized they're banking the effectiveness of the yet to fly hub fairing and some kind of advanced composite construction techniques? Composites scare me, they're why I chose to go the thermo route rather than structures in college.
busdriver02 is offline  
Old 8th Apr 2014, 13:34
  #46 (permalink)  
 
Join Date: Nov 2010
Location: Earth
Posts: 601
I like the source that says the scaling is limited. Any company exec is always the go-to source for technical information.
I wonder what motivation a government business development executive would have to sandbag and potentially depress stock prices. If anything, it would be to do precisely the opposite.
SansAnhedral is offline  
Old 2nd Oct 2014, 02:55
  #47 (permalink)  
 
Join Date: Aug 1999
Location: Gold Coast, Australia
Age: 71
Posts: 4,085
S97 Raider rollout scheduled for 2nd October in West Palm Beach, Florida.

John Eacott is offline  
Old 3rd Oct 2014, 14:07
  #48 (permalink)  
 
Join Date: Mar 2005
Location: Poplar Grove, IL, USA
Age: 52
Posts: 834
Pics of the real thing are out - looks great!
http://defensetech.org/2014/10/02/si...t-attack-helo/
Bryan
IFMU is offline  
Old 3rd Oct 2014, 20:40
  #49 (permalink)  
 
Join Date: Oct 2007
Location: USA
Posts: 147
Interesting to note based on previous discussion, I plopped those photos into power point to compare it against the X-2. Proportionally they're basically the same, disc spacing being the factor I was curious about.
busdriver02 is offline  
Old 4th Oct 2014, 04:51
  #50 (permalink)  
 
Join Date: Sep 2007
Location: USA
Posts: 600
The most interesting feature shown in these new pictures is the engine cowl. Nice clean installation of the single T706. Hard to tell, but it looks like they route the exhaust aft and disharge it just ahead of the pusher prop. Seems like it would be a good compromise between weight, thrust and IR suppression.

Nice detailing around the hubs and mast too.


riff_raff is offline  
Old 5th Feb 2015, 02:28
  #51 (permalink)  
 
Join Date: Feb 2015
Location: USA
Posts: 68
S-97 RAIDER now in ground test

Sikorsky is making progress! Aircraft is chained to the ramp and they've released a video of the first engine starts.



https://www.youtube.com/watch?v=CdBB...g&spfreload=10
SplineDrive is offline  
Old 21st May 2015, 02:17
  #52 (permalink)  
 
Join Date: Mar 2005
Location: Poplar Grove, IL, USA
Age: 52
Posts: 834
S97 Raider Journey to first flight video:




http://youtu.be/DHUc-rueOcQ
IFMU is offline  
Old 21st May 2015, 13:55
  #53 (permalink)  
 
Join Date: Nov 2010
Location: Earth
Posts: 601
Still waiting to see a sail fairing in action on a spinning ABC rotor head
SansAnhedral is offline  
Old 21st May 2015, 18:19
  #54 (permalink)  
 
Join Date: Oct 2002
Location: 1 Dunghill Mansions, Putney
Posts: 1,797
...and a first flight.
Ian Corrigible is offline  
Old 22nd May 2015, 15:19
  #55 (permalink)  
 
Join Date: Feb 2006
Location: On the big blue planet
Posts: 903
First flight!:

https://www.facebook.com/verticalmag...type=1&theater


skadi
skadi is offline  
Old 22nd May 2015, 15:39
  #56 (permalink)  
 
Join Date: Feb 2006
Location: The Alps
Posts: 2,035
Congrats to Sikorsky and Team Raider,

Cheers

(Photo courtesy of Sikorsky)

chopper2004 is online now  
Old 22nd May 2015, 16:32
  #57 (permalink)  
 
Join Date: Feb 2015
Location: USA
Posts: 68
Sail fairing...

Originally Posted by SansAnhedral View Post
Still waiting to see a sail fairing in action on a spinning ABC rotor head
On the videos, check out the stationary fastener pattern between the rotors. I think they solved that problem on RAIDER.
SplineDrive is offline  
Old 22nd May 2015, 16:37
  #58 (permalink)  
 
Join Date: Mar 2012
Location: unsteady
Posts: 346
It appears to have the side-stick for the copilot on the left side? That would be a rather odd design "feature". Especially highly experienced pilots better be really careful to trick their muscle memory into using the left hand for cyclic control. Could be difficult (read hazardous) in hairy situations.
What's the collective, cyclic up and down?
whoknows idont is offline  
Old 22nd May 2015, 17:02
  #59 (permalink)  
 
Join Date: Oct 2002
Location: 1 Dunghill Mansions, Putney
Posts: 1,797
See time index 1:17 for an explanation of the side-arm controller (collective), cyclic stick (yaw, pitch & roll) & pedals (brakes & comms), c/o Advanced Programs PM Jim Kagdis.



Kudos to Sikorsky on achieving their FF.

I/C
Ian Corrigible is offline  
Old 22nd May 2015, 17:37
  #60 (permalink)  
 
Join Date: Mar 2005
Location: Poplar Grove, IL, USA
Age: 52
Posts: 834
Congratulations to the Raider team! Very cool! The video looked great.
Bryan Cotton
Sikorsky/X2 Alumni
IFMU is offline  

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.