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Author Topic: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.  (Read 13980 times)

Offline 500 Fan

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I thought I'd start a topic covering the five scout helicopter programmes initiated to provide the US Army with turbine-powered scout helicopters from 1963 to the present day. The LHX and RAH-66 Commanche programmes should of course be included but they have their own topics so I left them out.


The various programmes are;


LOH - Light Observation Helicopter (1963). Reopened in 1968.
ASH - Armed Scout Helicopter. This was more of a theoretical programme for industry to develop new technology (1970's).
AHIP - Army Helicopter Improvement Programme. An "interim" programme to update the LOH until the LHX arrived (1981).
ARH - Armed Reconnaissance Helicopter. A mid-2000's programme that was cancelled due to high costs.
AAS - Armed Aerial Scout. The latest programme currently ongoing.   


The interesting thing is that after running four different programmes, LOH, AHIP, LHX and ARH, the US Army is still flying a scout helicopter based on an airframe selected in the late sixties.


The LOH programme of 1963 saw the entries narrowed down to three, Hiller (YOH-5), Hughes (YOH-6) and Bell (YOH-4). Initially the Hughes entry won and went into production. It gained a legendary reputation in Viet Nam but production problems at Hughes saw the LOH contest re-opened with Bell winning this time with the Bell OH-58A.


The ASH programme was probably generated from the planned purchase of the AH-56A Cheyenne. With the huge increase in capability that the Cheyenne would have brought, the US Army saw the future need for a more advanced scout helicopter that could work with the AAFSS. I don't think any actual ASH prototype was built but Hughes built a few interesting OH-6 helicopters in the mid-seventies that were possibly based on ASH requirements.


AHIP was a fight between the OH-6A and OH-58A for a programme that would see the winner being upgraded with lots of improvements including a mast-mounted sight. The OH-58D proved to be the winner and it is still in use today. Bell have even re-opened the production line to build a number of attrition replacements.


ARH was initiated after the cancellation of the LHX programme. The Bell ARH-70A Arapaho was selected as the winner but as the helicopter neared production, the costs had risen so high that the programme was cancelled.


AAS is the current contest to find a new scout helicopter for the US Army. Boeing, Eurocopter, Bell and Sikorsky are in the mix. Some sources have also mentioned AgustaWestland, probably with a version of the A109. Sikorsky are offering their S-97 Raider but that won't be flying for some time yet and will miss next month's initial AAS flight demonstration.  Just to confuse things, this competition was initially referred to as the "Armed Scout Helicopter".


There are plenty of photos and details available of the helicopters that went into production arising out of these contests in the past but less is known about the prototype helicopters flown in each programme or the helicopters that didn't win or even the proposals that were made by various companies that only ever made it into model or mock-up form. Plenty of export derivatives were also made of the various proposals that did fly, so if anyone has anything interesting to add, documents, drawings, photos or links, please add them here. The scout helicopter is often overshadowed by its big brother, the Attack Helicopter, so hopefully this thread will gather together a large pool of information on the the development of the US Army's turbine-powered scout helicopters from the early sixties to the present day.


500 Fan.   
« Last Edit: March 21, 2012, 12:45:27 pm by 500 Fan »

Offline Skyblazer

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #1 on: March 20, 2012, 03:02:46 pm »
Here is a series of pictures related to the LOH program:

1) The Bell D-250 full-scale mockup
2) An item on the first flight of the Bell Model 206 (YOH-4A)
3) The YOH-4A and YOH-5A contenders together
4) The Hiller Model 1100 full-scale mockup
5) An item on the first flight of the Fairchild-Hiller FH-1000 (YOH-5A)
6) The announcement of the flyoff between the three contenders
7) An inflight photo of the first Hughes 369A in flight (YOH-6)
8) An item on the first flight of the Hughes 369A (YOH-6A)

Some important notes:
  • The Bell contender was only designated as plain Model 206. It lost the competition and was quite different from the later Model 206A (Jet Ranger) which became the H-57/H-58.
  • At the time of the selection, the designations were YHO-4, YHO-5 and YHO-6 in the old Army HO- (Helicopter Observation) list. By the time the prototypes flew, they were redesignated as YOH-4A, YOH-5A and YOH-6A in the new tri-service H- (Helicopter) list, with the "O" prefix added for observation.
  • At that stage, none of the contenders had received any popular name.
  • Please note the very different tail in the early stages of the OH-6A.
« Last Edit: March 20, 2012, 03:05:17 pm by Stargazer2006 »

Offline 500 Fan

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #2 on: March 22, 2012, 04:23:50 pm »
Here are some photos of the Bell YOH-4, along with some of the other entrants in the LOH competition. These photos are from the US Army Aviation Museum collection and are the result of extensive research carried out by Ray Wilhite aka "Rotorwash".



































The YOH-4 was eliminated in the first fly-off between the three entrants in the first LOH contest. Eventually it would be transformed into the OH-58A and would do quite well.


500 Fan.




Offline Skyblazer

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #3 on: March 22, 2012, 04:54:25 pm »
Magnificent pictures! Once again, rotorwash delivers... Thanks for sharing these, 500 Fan!

Offline Skyblazer

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #4 on: September 13, 2012, 05:42:21 pm »
Boeing Vertol ASH proposal. Please note that "ASH" here means "Advanced Scout Helicopter" (not "Armed...").

Source: ADVANCED SCOUT HELICOPTER (ASH) FLY-BY-WIRE FLIGHT CONTROL SYSTEM PRELIMINARY DESIGN Volume I - System Design and Analysis

Offline RAP

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #5 on: August 09, 2013, 12:18:03 pm »
Hope I have this in the right place.  A couple of drawings of the Hiller RH-1100M Hornet.


Offline Triton

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #7 on: December 08, 2013, 02:41:00 pm »
Wikipedia claims that this helicopter is the Bell OH-58X

Quote
The OH-58X was a modification of the fourth development OH-58D (s/n 69-16322) with partial stealth features and a chin-mounted McDonnell-Douglas Electronics Systems turret as a night piloting system; including a Kodak FLIR system with a 30-degree field of view. Avionics systems were consolidated and moved to the nose, making room for a passenger seat in the rear. No aircraft were produced.

Quote
OH-58X Kiowa. Modified OH-58D prototype. Note nose, pitch link cover and engine cowl area

Source:
http://en.wikipedia.org/wiki/Bell_OH-58_Kiowa
http://1000aircraftphotos.com/Contributions/HatcherDavid/5950.htm
« Last Edit: December 08, 2013, 02:42:45 pm by Triton »

Offline jsport

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #8 on: December 09, 2013, 11:32:48 am »
Wikipedia claims that this helicopter is the Bell OH-58X

Quote
The OH-58X was a modification of the fourth development OH-58D (s/n 69-16322) with partial stealth features and a chin-mounted McDonnell-Douglas Electronics Systems turret as a night piloting system; including a Kodak FLIR system with a 30-degree field of view. Avionics systems were consolidated and moved to the nose, making room for a passenger seat in the rear. No aircraft were produced.

Quote
OH-58X Kiowa. Modified OH-58D prototype. Note nose, pitch link cover and engine cowl area

Source:
http://en.wikipedia.org/wiki/Bell_OH-58_Kiowa
http://1000aircraftphotos.com/Contributions/HatcherDavid/5950.htm
Thank you Triton for the second OH-58X pic.. Not too many pics on the Internet..

CostasTT

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #9 on: December 09, 2013, 12:44:08 pm »
I also had these in my HDD as OH-58X (unfortunately, I can't recall where I got them from).

Offline quellish

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #10 on: December 09, 2013, 01:07:24 pm »
I also had these in my HDD as OH-58X (unfortunately, I can't recall where I got them from).

OH-58X_02 shows the aircraft with the actual (fielded) low observable mods. So that may not be the same OH-58X, but another aircraft with the LO modifications. I am not 100% certain the rotor head fairings were part of the fielded kit though.

Offline jsport

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #11 on: December 09, 2013, 01:08:08 pm »
I also had these in my HDD as OH-58X (unfortunately, I can't recall where I got them from).

familiar w/ these but thank you CostasTT...

Offline yasotay

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #12 on: December 09, 2013, 02:10:22 pm »
I also had these in my HDD as OH-58X (unfortunately, I can't recall where I got them from).

OH-58X_02 shows the aircraft with the actual (fielded) low observable mods. So that may not be the same OH-58X, but another aircraft with the LO modifications. I am not 100% certain the rotor head fairings were part of the fielded kit though.
The rotor head fairings were scrapped early in the considerations because they were a pain in the posterior for maintainers, for little gain.  There were practical safety concerns as well with combat damaged components flying into the rotor system with predictable results.

Offline quellish

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #13 on: December 09, 2013, 02:42:49 pm »
The rotor head fairings were scrapped early in the considerations because they were a pain in the posterior for maintainers, for little gain.  There were practical safety concerns as well with combat damaged components flying into the rotor system with predictable results.

Are you talking about OH-58X/Kiowa Warrior or about the OH-58 LO kit (circa 1990-1991)?

CostasTT

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #14 on: December 09, 2013, 04:47:35 pm »
I also had these in my HDD as OH-58X (unfortunately, I can't recall where I got them from).

familiar w/ these but thank you CostasTT...

You are welcome.

Offline yasotay

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #15 on: December 10, 2013, 06:27:47 am »
The rotor head fairings were scrapped early in the considerations because they were a pain in the posterior for maintainers, for little gain.  There were practical safety concerns as well with combat damaged components flying into the rotor system with predictable results.

Are you talking about OH-58X/Kiowa Warrior or about the OH-58 LO kit (circa 1990-1991)?
I was speaking of the LO kit, but I think the Army made the same determination had it gone forward with the OH-58X effort.

Offline 500 Fan

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #16 on: June 11, 2014, 07:45:00 am »
Here is a small video from Hughes Helicopters from around 1974. It features the AAS/ASH OH-6 conversion (01:51) that Hughes proposed in the 1970's as a scout for the AH-56 Cheyenne/ AH-64 Apache programmes as one was cancelled and the other was started. It also has footage of The Quiet One and an OH-6A fitted with a minigun and a four-shot rocket pod. Could that have been the OH-6B that Hughes proposed in the late sixties as an upgrade for the OH-6A?





Does anyone have any photos or drawings of the AAS/ASH Hughes OH-6?


500 Fan.

Offline 500 Fan

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #17 on: April 01, 2017, 10:08:21 am »
Does anybody know where I can find the technical details in the U.S. Army's "Request for Proposal" for the renewed LOH competition from 1967/1968 that was ultimately won by the Bell OH-58A? Apparently Hughes offered a version of their OH-6A that included a few improvements. I am trying to figure out what those upgrades might have been. Thanks.

500 Fan.
« Last Edit: April 02, 2017, 06:02:14 am by 500 Fan »

Offline Grey Havoc

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #18 on: April 02, 2017, 02:01:17 am »
Does anybody know where I can find the technical details in the U.S. Army's "Request for Proposal" for the renewed LOH competition from 1967/1968 that was ultimately one by the Bell OH-58A? Apparently Hughes offered a version of their OH-6A that included a few improvements. I am trying to figure out what those upgrades might have been. Thanks.

500 Fan.

The closest I've been able to come so far is this citation over on DTIC for a technical report [Rept. no. 5, 22 Apr-21 Jul 67] on the Light Observation Helicopter Avionics Package (LOHAP). You will have to apply directly for a copy of the report itself, I'm afraid.

EDIT: This may also prove useful, but again you will have to apply directly for the report. 
« Last Edit: April 02, 2017, 02:08:59 am by Grey Havoc »
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Offline Grey Havoc

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #19 on: April 02, 2017, 02:21:26 am »
This Engineering Flight Test report of the Light Observation Helicopter (LOH) OH-6A Armed (XM-27E1) from December 1967 is directly available: http://www.dtic.mil/get-tr-doc/pdf?AD=ADA951595
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Offline ZacYates

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #20 on: April 02, 2017, 09:24:20 pm »
Could that have been the OH-6B that Hughes proposed in the late sixties as an upgrade for the OH-6A?
I would very much like to see the B. And more of the AAS/ASH variant, too.

Offline 500 Fan

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #21 on: April 04, 2017, 05:28:56 am »
Could that have been the OH-6B that Hughes proposed in the late sixties as an upgrade for the OH-6A?
I would very much like to see the B. And more of the AAS/ASH variant, too.

I would too. I am currently researching the period between 1967 and 1978 when the US Army initiated a number of different programmes to find a new scout helicopter. So far, I have come across programmes entitled "New Initiatives Aerial Scout", "Advanced Aerial Scout", Advanced Scout Helicopter" and another interim scout helicopter programme that preceded the Army Helicopter Improvement Program (AHIP). Because most of these programmes were abandoned, very little info is now available on them and the technical specifications of the proposed helicopters. I am not sure what new versions of the OH-58 that Bell came up with during the 70's but there are a few images out there of what appears to be their NIAS proposal. Hughes had the OH-6C, OH-6C+ (both NIAS) and the OH-6D "Interim ASH" (this was only ever a proposal based on the 500D but probably never even resulted in any initial drawings being made up). 

500 Fan.,

Offline 500 Fan

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #22 on: August 24, 2017, 05:31:39 am »
The MD540A (previously known as the MD540F) was demonstrated to the Army as part of their AAS programme but ultimately this selection process never went ahead. The MD540A has now officially been cancelled, although this has been known about for some time. Presumably, the MD6XX will become MDHI's main focus when it comes to a modern H-6-based light attack/armed scout helicopter.

 http://www.janes.com/article/72806/mdhi-drops-development-of-md-540a-light-attack-helo

The prototype, N540HH, has been returned to MD530FF-configuration and is, I believe, still in use with MDHI as a test-ship. It test flew the new HTC main rotor blade that is destined for use on the MD6XX.

500 Fan.
« Last Edit: August 24, 2017, 08:06:14 am by 500 Fan »

Offline hesham

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #23 on: August 24, 2017, 05:57:43 am »
Nice Info,thanks.

Offline RAP

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Re: LOH, ASH, AHIP, ARH and AAS. US Army Scout Helicopter Programmes.
« Reply #24 on: December 29, 2018, 08:46:28 am »
Ad for Hughes LOH.