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Post Info TOPIC: The LHX Program


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Date: Jul 6, 2011
RE: The LHX Program
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More LHX, unknown source... derp.



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These last ones are the closest to the initial RAH-66 design to the point of it being impossible for any other to come closer. Great finds!



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Date: Jul 6, 2011
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Stingray wrote:

Yes and no. The requirements were changed sometime after Bell completed a few BAT (Bell Advanced Tiltrotor) mockup demonstrators. It had similar provisions for internally-stored armament, but it's weight was a problem since newer LHX requirements included a weight limit of under 3150kg. The BAT was 3600kg.


 Two words come to mind... Jenny Craig.



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Matt L. Webber


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I think you just hurt the poor BAT's feelings. It's bad enough it got disqualified from the program. Say you're sorry!



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Date: Jul 6, 2011
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Don't forget, Sikorsky tested the LHX advanced co.ckpit systems and aerodynamic validity with modified S-76 Spirit helicopters under the heading SHADOW (Sikorsky Helicopter Advanced Demonstrator of Operators Workload). Problem with coc.kpit evaluator was that it was to study one-man operation and proved to be a huge risk to the pilot.

McDonnell-Douglas also tested their advanced LHX co.ckpit on the AH-64A. How many of these were tested? One or two? Or more, perhaps?



-- Edited by Gunship on Thursday 7th of July 2011 04:15:06 AM

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Alan Dallas


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Date: Jul 6, 2011
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Just one.

The second SHADOW aircraft (N3124G) tested the shape of the Fenestron tail rotor of the Comanche. Same reason it was fitted to the S-67 "Blackhawk", but I'm not sure if it was the exact same rotor system.



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The LHX is sexy. XD



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Date: Nov 7, 2011
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I've found this topic very interesting, and is the sole reason that I decided to become a member of the forum.



-- Edited by Flyboy on Tuesday 8th of November 2011 03:34:05 AM

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I'm glad you like it! I think you'll enjoy this place very much, as new things are discovered almost every day here.



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Stingray wrote:

I'm glad you like it! I think you'll enjoy this place very much, as new things are discovered almost every day here.


 Yeah, such as Stingray's newest TV addictions for instance... disbeliefno



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Sidewinder wrote:

These last ones are the closest to the initial RAH-66 design to the point of it being impossible for any other to come closer. Great finds!


What about it actually being the initial RAH-66? If you think about it, that comment doesn't make that much sense.

Anyway, not sure if this is true or not, but I heard a rumor that Bell and McDonnell Douglas flew a technology demonstrator of their proposal in the Nevada desert before the Army selected the Boeing/Sikorsky entry (future RAH-66).



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Date: Dec 29, 2011
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You might be referring to the AH-64A prototype used to test the advanced flight systems. I do believe that particular aircraft was tested in the Nevada desert. But that is closest I've ever heard of regarding a demonstrator of the design.



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Alan Dallas


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Date: Dec 29, 2011
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Gunship, it tested the NOTAR technology as well. It was truly a sole demonstrator to the Super Team proposal so the rumor is in fact true.

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That seems highly unlikely. Can you confirm that with a valid source?



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Alan Dallas


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Date: Dec 29, 2011
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Gunship wrote:

You might be referring to the AH-64A prototype used to test the advanced flight systems. I do believe that particular aircraft was tested in the Nevada desert. But that is closest I've ever heard of regarding a demonstrator of the design.


That could be it. Thanks for clearing it up.

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Date: Dec 29, 2011
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Gunship wrote:

That seems highly unlikely. Can you confirm that with a valid source?


 

Check it out:

http://stingraysrotorforum.activeboard.com/t37003466/hughes-mcdonnell-douglas-ah-64-apache/?page=2#lastPostAnchor



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Date: Dec 29, 2011
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Wow. How in the world did they manage that without heavily modifying the tail boom?! 



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Alan Dallas


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SuperStallion wrote:
Sidewinder wrote:

 

These last ones are the closest to the initial RAH-66 design to the point of it being impossible for any other to come closer. Great finds!


 

What about it actually being the initial RAH-66? If you think about it, that comment doesn't make that much sense. 

Anyway, not sure if this is true or not, but I heard a rumor that Bell and McDonnell Douglas flew a technology demonstrator of their proposal in the Nevada desert before the Army selected the Boeing/Sikorsky entry (future RAH-66).


 

I was referring to the fact that First-Team's proposal was the closest to the RAH-66 in comparison with the Super-Team submissions that were later dropped by the Army. Sorry for the confusion.

And by the way guys, the AH-64 demonstrator dod not actually test the proposed NOTAR technology! If you look closely at the photo you can see the full-scale outline of the concept bird painted on the side of the fuselage. The array of "vents" near the tail rotor that suggests the NOTAR installation is nothing more than a picture painted onto the tail!



-- Edited by Sidewinder on Thursday 29th of December 2011 10:07:38 PM

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Date: Dec 29, 2011
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Ah, that makes perfect sense. The original, unmodified tail boom left me highly dubious to such an installation. Thanks Sidewinder.



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Alan Dallas


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Date: Dec 31, 2011
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A NOTAR Apache would've been an awesome machine, though! aww



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Date: Dec 31, 2011
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VinceJ wrote:

A NOTAR Apache would've been an awesome machine, though! aww


 Awesomely ugly you mean!  The Apache is the ugliest attack aircraft in the world.  Very friggin deadly, but still the ugliest attack helo out there IMHO. OK, maybe I'm being abit hasty, the Suiperhind is pretty friggin homely as well.  Looks like a Apache and a Hind had a kid!

   Ray



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mil


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Date: Jan 23, 2012
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What beautiful helicopter from Bell/McDonnell-Douglas under program LHX



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Date: Jan 24, 2012
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rotorwash wrote:
VinceJ wrote:

A NOTAR Apache would've been an awsome machine, though! aww


 Awesomely ugly you mean!  The Apache is the ugliest attack aircraft in the world.  Very friggin deadly, but still the ugliest attack helo out there IMHO. OK, maybe I'm being abit hasty, the Suiperhind is pretty friggin homely as well.  Looks like a Apache and a Hind had a kid!

   Ray


 

 

I believe that one of the problems with NOTAR is that as density altitude increases, its thrust decreases more rapidly than a tail rotor.   So, while it would work fine at lower altitudes, it might not have been the best choice for hovering hot and high.



-- Edited by NATF on Tuesday 24th of January 2012 11:06:23 PM

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Pepper wrote:

I think you just hurt the poor BAT's feelings. It's bad enough it got disqualified from the program. Say you're sorry!


 I realize this is an older post, but here's a bit more history. 

 

 

Originally, the LHX program was willing to use advanced rotorcraft technology for increased perfromance in meeting their mission needs, and to advance the state of the art.   Bell proposed their Advanced Tilt-Rotor concept, and one of the concepts Boeing was looking at was a Tilt-Rotor as well.   Tilt-Rotor was really the only advanced technology that looked like it could be ready for production in the Army's time frame, so it looked like the competition might come down to these two.  In addition, if they teamed (not that they had planned to, but if), they'd likely be the only bidder who could provide what the Army needed. 

One could also speculate that what looked like a fixed wing aircraft zipping around at 280-300 knots might draw the wrath of the Air Force. 

For whatever reason, Army changed the requirements to favor a conventional helicopter.   So, requirements were lowered to what a conventional helo could achieve.  In the revised solicitaiton, no credit would be granted for performance above that.  In addition, the Army specified an upper limit on empty weight and engine power that precluded Tilt-Rotor (the smaller the vehicle the biggger the proportion of total empty weight contributed by the wing).    This effectively "specified out" Tilt-Rotor when the actual solicitation hit the street. 

So, Bell's design did not get disqualified, because it was never got to the stage where it was bid--it couldn't have won.   That's why the "Super Team" and the "First Team" bid conventional helos.   Ironically, Army ended up relaxing the weight and power limitations anyway, to the point where a Tilt-Rotor would have been viable. 

 

 

 



-- Edited by NATF on Wednesday 25th of January 2012 07:14:46 PM

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Date: Jan 24, 2012
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NATF, much thanks for the information. There were many details about the BAT that I was still unclear about, and now I'm thankful to say most of it has been cleared up.

Welcome and enjoy the forum!



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Date: Jan 24, 2012
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Thanks NATF and welcome aboard! The BAT and all the tilt-rotor programs at Bell have always been a pet subject of mine...

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Date: Jan 24, 2012
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Thanks

 

Some have opined elsewhere that Boeing did not actually consider Tilt-Rotor for LHX before the requirements were dumbed down.    I actually have a picture of the Boeing concept, but under the conditions with which it was provided to me, it was for my research and I can not pass it on. 

 

I will say that I have seen the illustration appear at least two times in print , but in neither case were they identified as the Boeing Tilt-Rotor LHX concept.  As a result, I can't really point anyone to them or I would be violating my confidentially agreement with the provider. 

 

BTW, if you do a Google image search for "Boeing Tiltrotor LHX" among the images you'll get are two labled, "A Boeing proposal for a tilt-rotor LHX attack helicopter".  Those are NOT it. 



-- Edited by NATF on Wednesday 25th of January 2012 02:38:15 AM



-- Edited by NATF on Wednesday 25th of January 2012 06:52:12 PM

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Couple of other notes:

The BAT (and no doubt the Boeing model) far exceeded the eventual requested performance for LHX, not surprising because the original LHX requirement was considerably higher before it was "dumbed down" to suit and I believe actually specify a conventional helo. The BAT carried normally carried eight Hellfires internally. Army also originally had an overload requirement for 12 Hellfires. BAT could do that plus two Stingers and 130 cannon rounds and hover out of ground effect in hot and high. In fact, it could carry 18 Hellfires (max loadout was 20), 750 rounds and four Stingers and still hover out of ground effect @ 610 meters on a 70 degree day. Of course, the extra Hellfires went under the wing.

And a picky note: I hate picking on the administrator, but there's a picture earlier in this topic labeled "Another McDonnell-Douglas project, for NOTAR a supersonic jet helicopter/fighter". Actually, that's Hughes' original design for LHX before the requirements were lowered, and Hughes got eaten by MDD, and it was nowhere near supersonic. In fact, it wouldn't be nearly as fast as the BAT (or Boeing). Think about it...Air Force would NEVER let Army have ANYTHING that approached the Mach!



-- Edited by NATF on Thursday 26th of January 2012 07:12:07 PM



-- Edited by NATF on Friday 27th of January 2012 12:05:02 AM

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NATF wrote:

And a picky note: I hate picking on the administrator, but there's a picture earlier in this topic labeled "Another McDonnell-Douglas project, for NOTAR a supersonic jet helicopter/fighter". Actually, that's Hughes original design for LHX before the requirements were lowered, and Hughes got eaten by MDD, and it was nowhere near supersonic. In fact, it wouldn't be nearly as fast as the BAT (or Boeing). Think about it...Air Force would NEVER let Army have ANYTHING that approached the Mach! 


 

Corrections and clarifications are always welcome. I'm still learning.

EDIT: This error has been fixed.



-- Edited by Stingray on Sunday 3rd of January 2016 05:03:47 PM

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Date: Feb 3, 2012
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One of the Comanche's concept drawings, sorry for 2 part picture scan from magazine and cutaway scan from Russian magazine.



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