Saab 37AU Fighter Viggen: A21 − Australian JA 37 derivative (1970 − 1976)

Apophenia said:
And Hellyer's erstwhile mentor, Northrop's T.V. Jones, had always wanted the F-5 to be a light carrier fighter ;)
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Well here you go... ;) :

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I just came across this proposed Viggen variant for the RAAF. A very interesting what-if and an extremely ambitious one at that.

Is there any information on what radar was planned to be used? To take advantage of the AIM-54 something powerful would be required. I don't believe the improved radar used by the JA-37 interceptor had entered service by that time, and even then I doubt that had the range of F-14's AWG-9 due to simple size/power limits.

The plan to redesign the intakes seems odd since the JA-37 is supposedly already capable of going over Mach 2 and how much speed you could get beyond that probably won't matter very much, since the Viggen isn't carrying some exceptional amount of fuel.
 
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Colonial-Marine said:
Is there any information on what radar was planned to be used? To take advantage of the AIM-54 something powerful would be required. I don' believe the improved radar used by the JA-37 interceptor had entered service by that time and even then, I also doubt that had the range of F-14's AWG-9 due to simple size/power limits.
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Not given by any sources i have, but the nose on the scale mockup is smaller than the JA 37s, so they probably proposed some american radar unit.

Colonial-Marine said:
The plan to redesign the intakes seems odd since the JA-37 is supposedly already capable of going over Mach 2 and how much speed you could get beyond that probably won't matter very much, since the Viggen isn't carrying some exceptional amount of fuel.
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The new intake was on behalf of the Aussies iirc. The JA 37 was capable of mach 2 but it couldn't achieve such speeds on the regular. The oblique intakes would supposedly help it reach and perform better at such speeds. It was noted however that the Aussies asked for a lot which from a Swedish POV was seen as unnecessary.
 
The Mirage 2000D / 2000N had something similar. Being low level attack variants, the "mices" (typical of all Mirages) were fixed in place; restricting top speed at altitude to Mach 1.4.
 
First photo on thread shows a built 'What-if' 72 scale model kit in SPECULATIVE colour scheme and NOT an official model :/

The ARDU tail markings and the addition of Phoenix missiles (no doubt from an F-14 kit) is a further alarm bell, a nice model as a what-if, but BS. as a model as proposed
 
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TsrJoe said:
First photo on thread shows a built 'What-if' 72 scale model kit in SPECULATIVE colour scheme and NOT an official model :/
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Any source? (edit: im not disputing, but u know were this came from?)
 
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Hello!

I would like to resurrect this thread with new information. While researching for a blog post devoted to the 37AU I get in contact with the Library of the Flygvapem Museum in Linköping to request a copy of the Aircraft Saab 37AU: specification. D.1 and D. 2.

Dated in February 1972, they describe the technical characteristics of the 37AU specially the reasons why it was a solid candidate for the RAAF requirement. Here are a couple of interesting details:

-Ericsson UAP 1022 multimode Doppler radar (Maybe a derivative of the PS 46/A latter installed in the JA 37).
-Volvo Flygmotor RM8Mod engine (I think is the same as the RM8B)
-Armament:
-Air to air armament was going to be the AIM-7 Sparrow and the Saab RB372, plus a Oerlikon 304RK 30 mm gun pod.
-For Air to ground, Saab proposed the integration of the AGM-65 Maverick and the RB04 antiship missile along with rocket pods, bombs and a reconnoissance pod.
-The manufacture was open to discuss other armament options as required by the RAAF.
-Sophisticated avionics and navigation suite was going to be integrated.
-A less sophisticated and cheaper variant was proposed, called 37AU/2 that incorporated simpler avionics and a downgraded radar.

It's an interesting read. If you don't want to go through the 300+ pages of the report you can read the highlights in my blog post...;)
 
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NoBarrelRolls said:
They were kind enough to digitalize both documents and make them available as PDFs in their site:
https://flygvapenmuseum.welib.se/#/search?s=Aircraft%20Saab%2037AU%20%3A%20specification.&f=%7B%7D&so=%26sort%3Dscore%20desc&p=0&pp=10

;)
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Thanks for the summary.

I can't seem to get at the pdfs from this computer. Are there any illustrations of the variable ramp intakes developed in conjunction with Grumman*?

More broadly, I'm surprised that the mission radius requirement was only 250 miles. Given the size of Australia I would have thought longer ranges would have been desired.

*I hadn't heard this before. I find it interesting to now know that Grumman was involved with two aircraft I quite like, the Viggen and the Lavi, although significantly more in the latter case than just the intake ramps with the 37AU.
 
apparition13 said:
Thanks for the summary.

I can't seem to get at the pdfs from this computer. Are there any illustrations of the variable ramp intakes developed in conjunction with Grumman*?

More broadly, I'm surprised that the mission radius requirement was only 250 miles. Given the size of Australia I would have thought longer ranges would have been desired.

*I hadn't heard this before. I find it interesting to now know that Grumman was involved with two aircraft I quite like, the Viggen and the Lavi, although significantly more in the latter case than just the intake ramps with the 37AU.
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Hi apparition,

The Saab report briefly mentions the intakes but doesn't go deeper into their characteristics, moreover the illustration of the aircraft included doesn't look (at least to me) different than the regular AJ or JA 37.
Nevertheless, the report does mention that this feature is going to be omitted in the cheaper 37AU/2 variant causing a reduction in performance.

The detail of the Grumman involvement was taken from other sources.
 
I'd like to know/see more on this notional Aim-54 incorporation into this Saab 37AU study/proposal, given the size, weight and drag of the Aim-54 vs. the already questionable range of the Viggen design. Also, if I may, wasn't the specialised LAU-93 missile launcher integral to the use of the Aim-54? which I don't see associated with the 37AU/Aim-54 depiction.

Regards
Pioneer



 
I think how they squeezed relevent electronics for AIM-54 use into the Vigen is more the question.

It would help the design seems to only carry 2 such AAMs. So arguably the radar and missile computer boxes can be simpler and smaller.
 
blockhaj said:
In early 1970, the Aussies sent a request to Saab that they wanted to procure the in-development fighter variant of the Saab 37 Viggen (JA 37) as a replacement for their aging Mirage III. Saab got green light for export and sent classified preliminary documentation in December 1970. Swedish standards were seen as unfavourable, despite noting good track record. Requirement specs came at the end of 1971, aiming for a 1976 delivery.

In March 1972 specs were done for the planned Saab 37AU, which was supplemented with a proposal for collaborate license production to revive the dying Australian aviation industry. During the same period the design competed against the Mirage F1 and the Northrop Cobra. On May 11 1973, a formal offer for 27, 67 or 127 aircraft was made and the Australian aviation industry was invited to become part of the projects development, including future plans, as well as green lighting license production of the engine, spare parts and electronics. It was given the preliminary serial designation A21.
View attachment 706544
Saab 37AU mockup. Of note: what appears to be AIM-54 Phoenix missiles on the intake pylons, the aerial refueling probe on the nose, the A21-002 serial designation on the tail, the redesigned nose which appears smaller than the nose of Swedish Viggens.

The Saab 37AU was relatively different from the Swedish JA 37 base in several aspects, such as requirements for increased speed, increased lifespan and different armament etc. Saab, in collaboration with Grumman, spent lots of money into the development of oblique intakes to handle Mach 2+ flight. The project came to a stop however with the 1975 Australian constitutional crisis, with only a full scale mockup of the intakes being done.

In 1976, procurement restarted. The new government found the Saab 37AU too expencive and inquired the costs of 72 AJ 37 or JA 37 aircraft. At this phase, however, the inquiry was also sent out to all other possible aircraft suppliers. Saab 37 was examined by Australian politician and diplomat Lance Barnard, the Australian ambassador to Sweden at the time (possibly after his term). American aircraft was however favorised, and in 1981 Australia ordered 75 F/A-18 Hornet strike fighters, with deliveries in 1985, ten years later than originally planned for the Saab 37AU. The A21 serial designation went over to the F/A-18 instead.

According to one source (an overall good one but not perfect), the Aussies interest in Viggen started with the Australian defence minister, who was a former ambassador to Sweden. During his time in Sweden he had observed the Swedish aviation industry and cracked a plan to use it to rebuild the dying Australian aviation industry. No name appears and no defence minister was a Swedish ambassador before that post. Neither can i find anyone who fits into this story in the slightest, except possibly Lance Barnard, who was an ambassador post 1976 which actually inspected the Viggen (although what appears to be post 1979, at which point the project was effectively dead).
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I'm very late sorry, but may I ask, where did you get that mockup picture? Awesome job researching this thing btw.
 
Panzer said:
I'm very late sorry, but may I ask, where did you get that mockup picture? Awesome job researching this thing btw.
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I'd be interested in the photo origin too. (However, that is a model not a "mockup" - I suspect it is the old Esci/Airfix 1/48 kit with Hornet serials (and ARDU decals) applied.
 
Apophenia said:
I'd be interested in the photo origin too. (However, that is a model not a "mockup" - I suspect it is the old Esci/Airfix 1/48 kit with Hornet serials (and ARDU decals) applied.
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yeah right! sounds very plausible
 
Apophenia said:
Care to clarify?
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sorry, english isn't my first language. Didn't realize until now that it sounded ironic in text. What I meant was: Yeah, right. The photo origin is indeed interesting. And that you said about the model 1/48 etc etc is a very plausible explanation. Sorry if it came out weird
 
The SAAB 37 two-seaters in those what-if Aussie liveries are markedly different from the actual two-seaters (Sk 37). Is there anything else on that proposed configuration?
 

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