AX Contenders (alternatives to the Fairchild A-10 Thunderbolt II)

overscan

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OK, lets go back to the AX competition and the original bids submitted.

On May 8th, 1970, the AX SPO issued a request for proposal (RFP) to 12 aircraft manufacturers. Six of the 12 companies given the RFP responded with proposals: Boeing, Cessna, Fairchild Hiller, General Dynamics, Lockheed and Northrop.
Cessna's submission

Source:
A-37 in Action, Squadron-Signal
 

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overscan

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These were found on the internet. No confirmation of authenticity...

During the summer of 1967, tests were conducted in the Langley 7- by 10-Foot High-Speed Tunnel on designs submitted by Grumman, Northrop, McDonnell, and General Dynamics. In 1970, the requirements for the A-X mission were changed, and the Air Force issued a new request for proposals (RFP). Six companies responded to the RFP
http://oea.larc.nasa.gov/PAIS/Partners/A_10.html

The Grumman design must be from the 1967 period, as they did not respond to the 1970 RFP
 

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Antonio

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Overscan,

both pictures are authentic. I post it about two years ago in whatifmodelers forum in a thread about AX contenders.

You can find the Boeing Vertol AX on page 47, Le Fana de l'Aviation number 384. November 2001. The Article is Northrop YA-9, rapace resté poussin by Alexis Rocher. Excellent article, I recommend it ;)

Grumman AX contender is a Mohawk derivative. Lark sent me a photocopy from AW&ST (I think) to take the scan for whatifmodelers forum. According to that article, it is Grumman's proposal to AX, not an unsolicited design...


Regards,

Antonio
 

overscan

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I think you misunderstood me.

There were two phases of the AX program. Stage 1 in 1967, where Grumman were involved, was primarily a COIN aircraft, Vietnam style, and so turboprop designs made sense. In 1970, the requirements were altered in such a way as to favour a turbofan powered design, and Grumman appear to have declined to bid at this time, given that their design was probably not appropriate for the new RFP.
 

Antonio

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You're right, plase accept my apologies.

I misunderstood you because I didn't knew about that two phases. I thought it was only one. Thanks for your comment, this information gives me a new light about the AX competition....in fact I didn't understand well the disparities between the contenders.
Now I can see it clearly:

Stage I (1967):

Turboprop, a sort of heavy weight COIN

Grumman
Boeing Vertol
Cavalier Turbo-Mustang III

Stage II (May 1970):

Jet (Double flux), big gun (GAU-8 program started in November 1970)

Northrop
Lockheed
Fairchild
Cessna
 

lark

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A-10 contenders...

6 March 1967 : first RFP send to 21 manufactureres.
Design studies for a low cost attack aircraft under designation A-X

2 May 1967 : preliminary designs studies awarded to General Dynamics , Grumman
Northrop and Mc Donnell

meanwhile need arose for an aircraft able to accurate strafing in close proximity
of friendly forced (results of Vietnam war)
and
an aircraft with a gun suitable for knocking out tanks(results of 6-day war in June 1967)

7 March 1970 - definitive RFP send to 12 manufacturers.Submission date 10.8.1970
Of the dozen manufacturers that received an A-X RFP , six responded in time.

Boeing Vertol , Cessna, Fairchild Republic Aviation division , General Dynamics
Lockheed and Northrop.
Boeing Vertol submitted the only prop. driven design and was quickly eliminated.

18 December 1970 - two contractors selected : Fairchild and Northrop.
March 1971 Nortrop and Fairchild received official designations.
YA-9 for Northrop and YA-10 for Fairchild.

So far....

Several sources .Ammong them Fairchild A-10 Thunderbolt II - Ian Allan.
The Thunderfactory- Joshua Stoff- Arms & Armour

P.S The Lockheed contenders L-1400-1 and L-1400-2
are on page 205 of "Lockheed Skunkworks" -Jay Miller . Aerofax.

Paul.
 

Matej

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www.hitechweb.genezis.eu
Under picture named "GrummanAX" was originally written:

Configuration based on the OV-1 Mohawk is one concept under study by Grumman Aerospace Corp. for the expected USAF AX ground-support aircraft program. The concept incorporates a new nose and cockpit section, strengthened fuselage and wings and more powerful engines, probably turboprops. The AX design would carry a lighter avionics load than current reconnaissance version of the Mohawk, but would have a greater weapons stores capacity.

Used words "expected USAF AX program" indicates, that it was before 1970 era.
 

overscan

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The USAF has issued requests for proposals for its single-seat twin-engined AX close support aircraft to 12 companies. The proposals are scheduled to be presented within 90 days of the issue of the request, and the evaluation of the competitive RFPs is expected to be completed in approximately 75 days of their receipt. Two of the contenders will then be selected for a 26-month competitive development phase. Envisaged as a relatively simple and inexpensive aircraft capable of supporting mobile army units from forward-area strips, the AX will be powered by twin turboprops with the Lycoming T55 as the primary candidate, will carry an ordnance load of the order of 8.000 lb (3 629 kg) and possess a combat radius of some 290 miles (470 km). Primary requirements include a low-cost navigation system, 30-mm rotary cannon armament, and high survivability.
Flying Review International, July 1970
 

Antonio

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the AX scan comes from Le Fana


[picture from initial post by Jemiba attached here for coherence]
 

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Jemiba

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"the AX scan comes from Le Fana"

Thanks, I'll add it to the description, although I found it somewhere
in the net. Is there any relàtion to the model 147 ?
 

Antonio

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I posted it for the first time at whatifmodelers forum about 3-4 years ago. I can't remember if it is any relationship with Model 147 but I'll try to verify it later
 

Antonio

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Dear Hesham,

I'm sorry but I can't understand very much the text but I can't find the reference to the Model 147. Can you tell me where is it?.


This is for Jemiba

Le Fana Nº384. November 2001 "Northrop YA-9" by Alexis Rocher
The Boeing AX drawing is on page 47. According to the text, there was an internal design competition: Boeing against Vertol. Vertol with Mark Kirshner's project won. That project was based on tilt wing studies after the Type 76.

I hope this info could be useful :)

cheers
Antonio
 

Pioneer

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Great find with the Northrop 'early AX design' drawings, Overscan!
Does the Patent info you found have any technical data/specifications ????

Regards
Pioneer
 

elmayerle

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overscan said:
Found via google patent search. Northrop design, seems to be related to early stages of AX.

Patent: D218,856
Shades of the Learfan!!
 

JAZZ

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Interesting find ...thought i would have a go at quickly dressing one of the drawings up...prehaps I should post this under-models-art?
 

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overscan

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Unfortunately, its an "ornamental design" patent and includes little information except it was "made in the course of Contract No. F33657-67-C-100 with the United States Air Force" and filed June 30, 1969.

Nice addition to the drawing, Jazz.
 

overscan

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Found a little mention of this here: http://aeroweb.brooklyn.cuny.edu/specs/northrop/ya-9a.htm

I worked at Northrop (now Northrop-Grumman) in the 1980s.
When I visited the March AFB/ARB Air Museum, I finally
got my first chance to see and touch one of the A-9A prototypes.

The most unusual variant of the A-9A proposed was a
desktop 1/48th scale model of a PROPELLOR version of
the A-9A. The propellor arrangement was a PUSHER
configuration, with 3 tail fins arranged in a Y shaped
configuration: 1 ventral fin, 2 angled dorsal fins.

I am not sure what they had in mind with that concept
model - perhaps a slower, Skyraider type attack craft.
I'll probably never know for sure, but the model was
interesting.
So theres a model on display at March AFB Museum? Or is he referring to somewhere else?
 

lark

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Northrop Corp. produced a flying demonstrator of its
turbo-pusher concept.

A photo is shown on page 26 of Aviation Week & Space Techno
of September 23 , 1968.
 

overscan

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Could you elaborate a little? What exactly is this demonstrator?
 

lark

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Illustration shows a little pusher aircraft with fixed 3 wheel undercariage.
3th wheel in the lower tailfin.

Pusher prop at the extreme tail end.

Overall configuration is close to the drawings already shown
but plane looks no so big.

'Northrop Turbo pusher' written on the side of the aircraft.
 

amsci99

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Matej,

This looks like the Sierra Sue and there is an article on it in Air Enthusiast. The link is at
http://shop.keypublishing.com/acatalog/Air_Enthusiast_issue_116.html
 

amsci99

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Matej,

Unfortunately not. I am trying to track down a used copy on eBay.
 

overscan

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http://airpower.callihan.cc/HTML/Spotlight/SierraSue.htm

http://web.mit.edu/asfalcon/www/Images/LAX%20Photos/2006_07_01_1/IMG_0652.JPG

Some pictures - its at the Western Museum of Flight.

The Southern California Historical
Aviation Foundation (SCHAF) has
proudly announced the arrival of
"Sierra Sue" at their Western Museum of
Flight in Hawthorne, California, where
it will be on display for an undetermined
period of time. A unique "pusher"
aircraft with a single propeller in
back of its tail, Sierra Sue was designed
and built in the 1950s as a race plane
by engineers at North American and
Northrop in their spare time. In the
late 1960s, it served as a concept
demonstrator in developing a prototype
attack aircraft for the U.S.Air Force, but
the design was dropped when the Air
Force announced its requirement for a
jet, rather than a propeller aircraft.
 

Antonio

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Thanks for the pics, Paul

In this photo, we can see the AX concept illustrated in the papers in front of the aircraft.
 

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overscan

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Unfortunately the Western Museum of Flight had to move and I'm not sure of the current status at its new site. If anyone is in the area, maybe they could visit and photograph the pics on the placard?

;D
 

Mark Nankivil

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I've been going thru all the older threads to see what else I may have info on or have interest in myself. This one I think I can help with as I have some drawings from Vought of a few of their proposals. I don't have any additional info other than these drawings - will try to find more on my next trip to the archives...

Enjoy the Day! Mark
 

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overscan

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Interesting - seems to be from the earlier (1967) phase of the AX competition.
 

Mark Nankivil

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That makes sense - I had thought that an A-7 variant was their entry in the final competition. I do know that A-7 was flown against the A-10 prior to committing to the A-10 full production.

Enjoy the Day! Mark
 

hesham

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Hi,

when I search about Douglas aircraft I find that
design for Northrop,I think it was COIN aircraft,
I don't remember if we spoke about it before or not.

http://www.google.com/patents?id=02t1AAAAEBAJ&printsec=abstract&zoom=4&dq=douglas+design+of+airplane&num=100#PPP1,M1
 

overscan

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http://www.google.com/patents?id=-Lk9AAAAEBAJ

Northrop A-9 patent. Just to confirm that the previous studies are AX studies, Walter E. Fellers is the first designer named on all three designs.
 

jackehammond

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Dear Members,

Did the Northrop YA-9A have any advantages over the Fairchild YA-10A design?

Jack E. Hammond
 

flateric

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Some good thoughts here
http://aeroweb.brooklyn.cuny.edu/specs/northrop/ya-9a.htm
 
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