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Author Topic: Fairchild A-10 Projects  (Read 75620 times)

Offline PaulMM (Overscan)

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Fairchild A-10 Projects
« on: March 18, 2006, 01:48:22 am »
I'm researching an article on the N/A W A-10 (A-10B) and came across this:

Quote
In 1976, Republic showed a model of the A-10 with long, slim nacelles housing non-afterburning versions of the YJ101 or RB199 engines, trading endurance for higher speed. This would have given an increase of 50 knots in level flight

Dennis R Jenkins, A/OA-10 Warthog Warbirdtech 20

Never seen this illustrated.
« Last Edit: July 14, 2006, 02:27:59 pm by overscan »
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Offline TinWing

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Re: Fairchild A-10 Projects
« Reply #1 on: March 18, 2006, 06:39:28 am »
I'm researching an article on the N/A W A-10 (A-10B) and came across this:

There were more than a few factors which militated against the two seat A-10. 

A conversion trainer wasn't really neccessary and pilot workload was manageable without a backseater. 




Quote
In 1976, Republic showed a model of the A-10 with long, slim nacelles housing non-afterburning versions of the YJ101 or RB199 engines, trading endurance for higher speed. This would have given an increase of 50 knots in level flight

Dennis R Jenkins, A/OA-10 Warthog Warbirdtech 20


RB199 engines?

Did Fairchild make an unsolicited proposal to the RAF?

Offline PaulMM (Overscan)

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Re: Fairchild A-10 Projects
« Reply #2 on: March 18, 2006, 07:00:26 am »
I don't think so. There is no reason to think that license produced RB199s couldn't have happened; Allinson made the Spey into TF41 for example. RB199 would simply have been the best engine for the job. YJ101 bypass ratio was low (around 0.2) which made SFC higher than desirable, while RB199 bypass ratio was about 1:1 giving a much better SFC (though still higher than the TF34 of course).
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Offline TinWing

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Re: Fairchild A-10 Projects
« Reply #3 on: March 18, 2006, 09:18:22 am »
I don't think so. There is no reason to think that license produced RB199s couldn't have happened; Allinson made the Spey into TF41 for example. RB199 would simply have been the best engine for the job. YJ101 bypass ratio was low (around 0.2) which made SFC higher than desirable, while RB199 bypass ratio was about 1:1 giving a much better SFC (though still higher than the TF34 of course).

A comparison between the J101 and the RB199 is hardly fair, if only because (until the LWF competition) the J101 was largely an industry funded demonstrator while the RB199 was a government funded tri-national project.  In this era, the USAF had very little interest in the GE J101 and the USN was still planning on the P&W F100 derived F401 as its future fighter engine.  It is very easy to forget that the definitive F404 is a much later development than the RB199.  Of course, you are correct about the conceptual differences between the J101 (or the subsequent F404) and the RB199.

I still have a hard time appreciating what tangible advantage an A-10 re-engined with the RB199 would have had, other than the quoted 50kt speed advantage?  Indeed, was the 50kt increase in performance available at sea level or medium altitude?

In addition, since the dry RB199 would have offered roughly the same thrust levels as the TF34, take off distances would have remained unchanged - despite the significant sacrifice in endurance. 

The main advantage of an RB199 A-10 would have been potential interchangability with the Tornado.  Perhaps a 50kt speed advantage would have made sense in light of the RAF's low level operating tactics, but it was irrelevant from the perspective of the USAF. 
« Last Edit: March 18, 2006, 10:02:59 am by TinWing »

Offline PaulMM (Overscan)

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Re: Fairchild A-10 Projects
« Reply #4 on: March 18, 2006, 12:34:50 pm »
I have found a posting from usenet, 1999:

Quote
Several years ago Rolls Royce offered to re-engine the A-10 fleet with a non afterburning version of their RB199 used in the European Tornado strike aircraft, this would have offered the A-10 more thrust and better acceleration.

Perhaps Fairchild looked at a YJ101 version, and the RB199 connection was an unsolicited proposal?
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Offline TinWing

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Re: Fairchild A-10 Projects
« Reply #5 on: March 18, 2006, 01:29:51 pm »
I have found a posting from usenet, 1999:

Quote
Several years ago Rolls Royce offered to re-engine the A-10 fleet with a non afterburning version of their RB199 used in the European Tornado strike aircraft, this would have offered the A-10 more thrust and better acceleration.

Perhaps Fairchild looked at a YJ101 version, and the RB199 connection was an unsolicited proposal?

Indeed, unsolicited proposals might have been made by the engine manufacturers. 

I believe that Jay Miller wrote that GE actually offered to pay Lockheed to incorporate the J101 in its LWF proposals.

In any event, I have read very little about Fairchild's attempts to export the A-10.  There was an attempt by Turkey to purchase 50 units through FMS, and it was claimed that USAF blocked the sale because it wanted to retain every stored airframe for cannibalization - or at least that was the excuse. 

Offline PaulMM (Overscan)

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Re: Fairchild A-10 Projects
« Reply #6 on: March 18, 2006, 03:36:11 pm »
Quote
Three customers, two in the Middle East and one in South East Asia, were leading candidates for A-10 sales... Fairchild expected to sell 75-80 aircraft in 1983-5

Quote
Fairchild pushed the use of the A-10 as a maritime strike aircraft, particularly in areas such as South-East Asia

Source:
Bill Sweetman, A-10 Thunderbolt II, Modern Fighting Aircraft 1984

Countries allegedly interested in A-10: Israel, Pakistan, Turkey, South Korea, Thailand, Egypt (unsourced claims on forums)


« Last Edit: March 18, 2006, 04:14:49 pm by overscan »
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Offline TinWing

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Re: Fairchild A-10 Projects
« Reply #7 on: March 19, 2006, 06:43:55 am »
Three customers, two in the Middle East and one in South East Asia, were leading candidates for A-10 sales... Fairchild expected to sell 75-80 aircraft in 1983-5

That was towards the end of the A-10's production run.

]
Fairchild pushed the use of the A-10 as a maritime strike aircraft, particularly in areas such as South-East Asia

Thailand eventually purchased used A-7E Corsair IIs - after abortive Tornado and AMX sales efforts.

Source:
Bill Sweetman, A-10 Thunderbolt II, Modern Fighting Aircraft 1984

Countries allegedly interested in A-10: Israel, Pakistan, Turkey, South Korea, Thailand, Egypt (unsourced claims on forums)

Pakistan was set to purchase the A-7E in the late 1970s but the sale was blocked due to concerns over its nuclear program.

« Last Edit: March 20, 2006, 10:48:51 am by overscan »

Offline lark

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Re: Fairchild A-10 Projects
« Reply #8 on: March 20, 2006, 10:54:42 am »
Dear All,

Modern Combat Aircraft 28 - "A-10 Thunderbolt II" by Mike Spick ,Ian Allan Ltd
shows on page 102 , a A-10 development with slim nacelles.
Caption reads as follow " How the A-10 could have developed; a night and all weather capable aircraft with a two-man crew,a thinner section wing,revised main gear housing, and much more powerfull low bypass ratio
engines probably base on the F404.

(General Electric)

Maybe you have something on this...

Lark.

Offline PaulMM (Overscan)

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Re: Fairchild A-10 Projects
« Reply #9 on: March 20, 2006, 11:20:54 am »
Excellent.

I'm seeing if I can buy a copy. I'm collecting the Ian Allan series anyway- I have 10 so far.

Paul.
« Last Edit: March 20, 2006, 11:22:29 am by overscan »
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Offline elmayerle

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Re: Fairchild A-10 Projects
« Reply #10 on: March 23, 2006, 10:05:21 pm »
I'm researching an article on the N/A W A-10 (A-10B) and came across this:

Quote
In 1976, Republic showed a model of the A-10 with long, slim nacelles housing non-afterburning versions of the YJ101 or RB199 engines, trading endurance for higher speed. This would have given an increase of 50 knots in level flight

Dennis R Jenkins, A/OA-10 Warthog Warbirdtech 20

Never seen this illustrated.

At a guess, I'd imagine it was more likely the evolved J101 intended for the production F-17.  As I  understand it, it was rather similar to the initial production F404.  Just as an aside, Northrop had laid out a RB.199-powered F-17 variant that might well have been quite popular in Europe.  The existence of this variant was confirmed to me by Dr. Ira Chart, their first official historian, while I was working there.

Offline TinWing

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Re: Fairchild A-10 Projects
« Reply #11 on: March 24, 2006, 09:44:30 am »
At a guess, I'd imagine it was more likely the evolved J101 intended for the production F-17.  As I  understand it, it was rather similar to the initial production F404.  Just as an aside, Northrop had laid out a RB.199-powered F-17 variant that might well have been quite popular in Europe.  The existence of this variant was confirmed to me by Dr. Ira Chart, their first official historian, while I was working there.

The F404 was scaled up somewhat from the J101.  The difference in mass flow between the J101 and RB199 would have been fairly great - in the same order of magnitude as the difference between the J-79 and Spey.

Northrop's efforts to market the YF-17 - and its unbuilt predecessors - in Europe were vigorous, but almost entirely unrealistic.  No Tornado/RB199 user had the slightest interest in the underdeveloped YF-17.  Germany was devoted to the of the F-4 as a interim alternative to the delayed Tornado, Italy was contented with licensed production of the F-104, and the RAF had absolutely no use for an air superiority fighter.  Rather foolishly, Northrop even attempted to sell the YF-17 to the French.

Offline elmayerle

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Re: Fairchild A-10 Projects
« Reply #12 on: March 25, 2006, 03:40:04 pm »
I got the impression that the "production" J101 would likely have been rather close to what became the F404.  I'm not certain, but that's the impression that I was left with at the time and what little I've seen of the proposed production F-17 appears to bear that out.  IMHO, the success of the F-5 was both a very good thing and a very bad thing for Northrop.  It was good in that it gave them a good profit base and solid finances to work from; it was bad in that they never developed the expertise to manage and market high-tech programs and, again IMVHO, both the B-2 and TSSAM suffered from this.  I rather suspect that this situation didn't help the F-18L, either.

Offline PaulMM (Overscan)

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Re: Fairchild A-10 Projects
« Reply #13 on: March 26, 2006, 01:06:18 am »
What I have read supports Evan's suggestion. YJ101 as fitted to the YF-17 was at a very early stage of development and would have ended up close to the eventual F404 even without the F-18 program.
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Offline TinWing

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Re: Fairchild A-10 Projects
« Reply #14 on: March 26, 2006, 06:42:02 am »
What I have read supports Evan's suggestion. YJ101 as fitted to the YF-17 was at a very early stage of development and would have ended up close to the eventual F404 even without the F-18 program.


Oddly enough, the Northrop's original P-530 from 1970 was roughly the same physical size as the final F/A-18A, but the later P-630 and YF-17 were significantly smaller.