Sikorsky X2 family

[yasotay]

At a high level, the survivability problem is the same for a rotorcraft as a fighter - but the numbers are different. Detection and engagement ranges are very different for helicopters and jets, but it's the relative differences that matter. For example, an F-117 can be engaging you and you would not even know it. An Apache is detectable long before it's within small arms range. There's the problem in a nutshell.
The X2 could spend less *time* in the defender's engagement zone, which may be an advantage.

Listening to Sikorsky... acoustically I would agree that the X-2 might well be less detectable than an Apache in some cases as they say the X-2 is VERY quiet with the propulsor fan at standby or low pitch setting. This with no first hand knowledge mind you. However with the X-2 having three rotating components (2 main [counterrotating] rotor and the thruster) versus two on the Apache (main and tail rotor) I am not sure the X-2 is less likely of acquisition by a radar system.

 

[donnage99]

Unlike apache though, the x2 has the tail fan blades visible from frontal view, the most critical facet for RCS reduction.

 

[yasotay]

Unlike apache though, the x2 has the tail fan blades visible from frontal view, the most critical facet for RCS reduction.

Exactly my point.

 

[donnage99]

bigger pictures?

 

[TomS]

New reports: the X2 demonstrator reached 181 knots on Tuesday!

http://www.ctpost.com/news/article/Sikorsky-s-X2-chases-world-speed-record-499655.php

 

[sferrin]

Got a ways to go before it eclipses the 40 year old Cheyenne.

 

[Matej]

X2 Technology™ Demonstrator Achieves 225 Knots, Sets New Top Speed for Helicopter - Target Milestone of 250 Knots Looms in Q3 2010

http://sikorsky.com/About+Sikorsky/News/Press+Details?pressvcmid=a4a2962fa4f0a210VgnVCM1000004f62529fRCRD

 

[Triton]

Artist's impression of Sikorsky X2

Source: http://www.w54.biz/showthread.php?28-Army-Aviation/page4

 

[yasotay]

Sikorsky picture (from Flight Global) showing the X-2 demonstrator with the new horizontal stabilizors for better pitch stability.
Another interesting piece at AVWEEK by a frequent contributor outlines the changes to the X-2 demonstrators configuration at: http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckBlogPage=BlogViewPost&newspaperUserId=27ec4a53-dcc8-42d0-bd3a-01329aef79a7&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3ab570fad6-df80-40df-93fd-5022070b4dc3&plckScript=blogScript&plckElementId=blogDest

 

[Triton]

Artist's impression of Sikorsky X2 concept.

Source: http://www.sikorsky.com/

 

[amsci99]

Pardon my ignorance but what's the overall difference between the XH-59A/S-69 and the X-2? I am sure there must have been significant re-design of the rotor geometry from the original XH-59A/S-69 beyond the incorporation of a drag-reducing hub and other measures to correct the deficiences with the its' predecessor.

 

[Dreamfighter]

As far as I know, main differences are (digital) fly-by-wire, active vibration control/suppression and slowing down of the speeds encoutered by the blades' and their tips (keeping them < Mach1)...

 

[flateric]

Pardon my ignorance but what's the overall difference between the XH-59A/S-69 and the X-2? I am sure there must have been significant re-design of the rotor geometry from the original XH-59A/S-69 beyond the incorporation of a drag-reducing hub and other measures to correct the deficiences with the its' predecessor.

X2 demonstrator has very specific patented MRBs planform shape

 

[yasotay]

And they there is the pusher prop on the X2 vice jet engines of the XH-59. Should have both impressive acceleration and deceleration abilities.

 

[amsci99]

Thank you all for your responses, just would like to check with flateric what's a MRBs planform shape, does that have to do with a minimal radar cross section area?

 

[flateric]

MRB = Main Rotor Blade
has nothing to do with RCS (at least in case with X2 Demonstrator)

 

[yasotay]

X-2 "unoffically" hit 250 knots! 260 knots in a slight dive!

 

[flateric]

just in case, Sikorsky has added some new hi-res X2 photos from previous August flight

 

[TomS]

X-2 "unoffically" hit 250 knots! 260 knots in a slight dive!

The 250 knot figure seems to be confirmed.

It's not an "official" record because X2 isn't a helicopter by FAI definitions.

 

[yasotay]

I think it "unofficial" because FAI was not there nor has it reviewed the data from the flight.

While I sympathize regarding the correctness of the terms used, but to 95% of the population it is a helicopter.

At the risk of starting a warmer discussion I seem to recall that the worlds "official" fastest helicopter had some residual thrust (10%?) coming out of the back of the GEMS for the effort. If so, that would mean that the "official" fastest helicopter was provided auxiliary thrust and therefore in a different category as well. ;D

I'm sure someone will inform me either way soonest. I am digging my deep bunker as you read this.

 

[TomS]

Actually, I'm going to retract my comment. Looks like the FAI definitions of "rotorcraft" and "helicopter" in the Sporting Code depend solely on how the vehicle derives lift, not thrust. My mistake.

2.1.1.2 AERODYNE : An aircraft, heavier than air, that can be dynamically sustained in the air
by the reaction of the air upon surfaces in relative movement.
2.1.1.3 ROTORCRAFT: An aerofyne that derives the whole or a substantial part of its lift from
a rotary wing system.
2.1.1.4 AUTOGYRO : A rotorcraft which, in its flight, derives most os its lift from an
autorotating rotar system not provided with any form of direct power drive.
2.1.1.5 HELICOPTER : A rotorcraft which, in flight, derives substantially the whole of its lift
from a power-driven rotor system whose axis (axes) is (are) fixed and substantially
perpendicaular to the longitudinal axis of the rotorcraft.

(Typos in original, here)

Based on that, the X2 certainly is entitled to the same category of records as G-LYNX. In which case the "unofficial" has to be, as you said, because either FAI wasn't present or hasn't confirmed the results yet.

 

[F-14D]

Sikorsky hit their 250 knot goal for the X2 last week. Do not know whether this was a dash or a cruise. They got to 260 in a shallow dive. Since they had a 20% power margin left, they're going to try for 265 in level flight.

 

[Sundog]

Sikorsky hit their 250 knot goal for the X2 last week. Do not know whether this was a dash or a cruise. They got to 260 in a shallow dive. Since they had a 20% power margin left, they're going to try for 265 in level flight.

265, that's outstanding. It would be great to read a pilot report of it, as I wonder about the vibration levels. Of course, I'm sure most of that info is proprietary atm. Based on how successful this technology appears to be, from the outside looking in, it will be interesting to see how fast they can mature it and get it into a production vehicle.

 

[F-14D]

Sikorsky hit their 250 knot goal for the X2 last week. Do not know whether this was a dash or a cruise. They got to 260 in a shallow dive. Since they had a 20% power margin left, they're going to try for 265 in level flight.

265, that's outstanding. It would be great to read a pilot report of it, as I wonder about the vibration levels. Of course, I'm sure most of that info is proprietary atm. Based on how successful this technology appears to be, from the outside looking in, it will be interesting to see how fast they can mature it and get it into a production vehicle.

They need to do a lot more development, and somebody's actually got to want to buy one, but I agree this is a very encouraging sign.

 

[bobbymike]

Video of speed record.

http://www.youtube.com/watch?v=gK7ktLXhq88&feature=player_embedded

 

[Sundog]

Great video. I want one. ;D

 

[Triton]

Photograph of the sail fairing installed on the Sikorsky X2 demonstrator.

Source:
http://www.flightglobal.com/blogs/as-the-croft-flies/2010/09/sikorsky-x2-speed-king---facts-figures-and-sail-fairings.html

 

[TomS]

And now it appears that Sikorsky is going to go ahead with flying prototypes of the X2 light tactical helicopter mock-up it's been showing around (already pictured many times in this thread). Two airframes, first flight in 2014.

Source:
http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckBlogPage=BlogViewPost&newspaperUserId=27ec4a53-dcc8-42d0-bd3a-01329aef79a7&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3a80df4fda-3798-4812-8187-d8cc81a97b64&plckScript=blogScript&plckElementId=blogDest

 

[Triton]

And now it appears that Sikorsky is going to go ahead with flying prototypes of the X2 light tactical helicopter mock-up it's been showing around (already pictured many times in this thread). Two airframes, first flight in 2014.

Source:
http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckBlogPage=BlogViewPost&newspaperUserId=27ec4a53-dcc8-42d0-bd3a-01329aef79a7&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3a80df4fda-3798-4812-8187-d8cc81a97b64&plckScript=blogScript&plckElementId=blogDest

Introducing the mockup of the Sikorsky S-97 "Raider".

 

[Triton]

Sikorsky Press Release:

"Sikorsky Commits to Build X2 TechnologyTM Prototypes to Advance Military Rotary Wing Operations"
http://www.sikorsky.com/About+Sikorsky/News/Press+Details?pressvcmid=da93b5ecd29cb210VgnVCM1000004f62529fRCRD

 

[Sundog]

That's awesome news and it's great to see them being so proactive about it. I look forward to seeing the S-97 fly.

 

[Triton]

The coaxial-rotor, compound helicopter, scheduled to complete first flight within 50 months, will carry weapons and troops like the Russian Mil Mi-24 Hind, but fly faster than 200kt (370km) in cruise, and 220kts in dash mode, Sikorsky says.

By officially unveiling the S-97 programme on 20 October, Sikorsky intends to challenge the US Army's requirements staff as they consider options for replacing the Bell Helicopter OH-58D Kiowa Warrior.

Artist's impression of Sikorsky S-97 "Raider".

Source:
http://www.flightglobal.com/articles/2010/10/20/348764/sikorsky-unveils-s-97-for-high-speed-scout-and-attack.html

 

[Nik]

The X-2's wary progress seems to have spooked Eurocopter into unveiling their notion for a compound helicopter.
http://www.flightglobal.com/articles/2010/09/27/347852/pictures.html

Of course, with those props on stub wings beside the cockpit, you have the 'walk into disk' problem in spades, plus no obvious way to fit hard-points away from the fuselage. Does mean that there's no cg issues from shrouding twin tail props, and a tail-ramp is possible...

FWIW, the article mentions the recipe for this prototype...

 

[Triton]

http://www.youtube.com/watch?v=3b4llljGObQ


http://link.brightcove.com/services/player/bcpid18065281001?bctid=643105987001


Source:
http://www.flightglobal.com/blogs/the-dewline/2010/10/videos-sikorsky-races-x2-then.html

 

[F-14D]

The X-2's wary progress seems to have spooked Eurocopter into unveiling their notion for a compound helicopter.
http://www.flightglobal.com/articles/2010/09/27/347852/pictures.html

Of course, with those props on stub wings beside the cockpit, you have the 'walk into disk' problem in spades, plus no obvious way to fit hard-points away from the fuselage. Does mean that there's no cg issues from shrouding twin tail props, and a tail-ramp is possible...

FWIW, the article mentions the recipe for this prototype...

Although anything that advances the state of rotorcraft technology is to be encouraged , IMHO both the ABC/X2 concept and Tilt-Rotor are so much better. X3 is still a compound with all the problems therein. Of course, our compatriots across the Big Pond have intimated that they'll be revealing another concept, an X4, in the not too distant future. Interesting times.

I am a little disappointed that the Army's Joint Multi-Role technology demonstration program is only asking for a speed of 170 knots. that's what killed advanced rotorcraft technologies on the LHX that became Comanche

 

[Triton]

What are the risks and disadvantages associate with Sikorsky's Advancing Blade Concept coaxial rotor and pusher propeller design? I have read that ABC was not used in the LHX program because of the transmission weight penalty. Are there issues that would cause the United States Army to reject X2 as a proposal for the Armed Aerial Scout program and go with a more traditional helicopter design?

 

[Matej]

Vibrations, vibrations, vibrations, then risk of the contact of the rotor lists and height of the vehicle (for example Ka-50 with its compound rotor head has the big problem in being transportable in the most of the platforms).

 

[robunos]

The X-2's wary progress seems to have spooked Eurocopter into unveiling their notion for a compound helicopter.
http://www.flightglobal.com/articles/2010/09/27/347852/pictures.html

Please see

http://www.secretprojects.co.uk/forum/index.php/topic,6856.msg58564.html#msg58564


cheers
Robin.

 

[yasotay]

The X-2's wary progress seems to have spooked Eurocopter into unveiling their notion for a compound helicopter.
http://www.flightglobal.com/articles/2010/09/27/347852/pictures.html

Of course, with those props on stub wings beside the cockpit, you have the 'walk into disk' problem in spades, plus no obvious way to fit hard-points away from the fuselage. Does mean that there's no cg issues from shrouding twin tail props, and a tail-ramp is possible...

FWIW, the article mentions the recipe for this prototype...

Although anything that advances the state of rotorcraft technology is to be encouraged , IMHO both the ABC/X2 concept and Tilt-Rotor are so much better. X3 is still a compound with all the problems therein. Of course, our compatriots across the Big Pond have intimated that they'll be revealing another concept, an X4, in the not too distant future. Interesting times.

I am a little disappointed that the Army's Joint Multi-Role technology demonstration program is only asking for a speed of 170 knots. that's what killed advanced rotorcraft technologies on the LHX that became Comanche

It is a minimum of 170 knot CRUISE speed. Taken into consideration with the range and VROC it will be very challenging for a conventional rotorcraft to get there. The top end is 300 Knots. As the "J" in JMR starts to take hold I think compounds and tilt rotors are going to be very competitive.

 

[F-14D]

Although anything that advances the state of rotorcraft technology is to be encouraged , IMHO both the ABC/X2 concept and Tilt-Rotor are so much better. X3 is still a compound with all the problems therein. Of course, our compatriots across the Big Pond have intimated that they'll be revealing another concept, an X4, in the not too distant future. Interesting times.

I am a little disappointed that the Army's Joint Multi-Role technology demonstration program is only asking for a speed of 170 knots. that's what killed advanced rotorcraft technologies on the LHX that became Comanche

It is a minimum of 170 knot CRUISE speed. Taken into consideration with the range and VROC it will be very challenging for a conventional rotorcraft to get there. The top end is 300 Knots. As the "J" in JMR starts to take hold I think compounds and tilt rotors are going to be very competitive.

Assuming they want to get other services to help fund the program (avoiding another JAST) why make 170 knots acceptable? The old CH-53 cruised only 20 knots slower and can meet the range, the RAH-66 cruised only 5 knots slower. If you want to push the technology, make a requirement that only advanced technology can reach. I'd still put my money on X2 and Tilt-Rotor for an advanced scalable vehicle, although I'd really like to see them go for two vehicles, one for the smaller and one for the larger. Might not use the same technologies for both vehicles, then again they might.

But then, they aren't asking me.


Hey! I wonder if US Aerospace will bid?