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DCS: AJS-37 Viggen Discussion


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Here is a video of SK60(a Swedish training jet) excising a typical Viggen attack maneuver where the plane is coming in at low altitude and then do a steep climb, roll over, then back again, fires of the armament quickly and then RTB.

 

This is what the Viggen was designed for and its why it did not have any cannon :)

 

That rocket smoke :shocking: :D

 

I'm going to be beta testing the Viggen tomorrow, I can't wait!

 

(a Saab 9-3 Viggen but that's pretty much the same thing, right?)

 

You got me for a moment there :D

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Here is a video of SK60(a Swedish training jet) excising a typical Viggen attack maneuver where the plane is coming in at low altitude and then do a steep climb, roll over, then back again, fires of the armament quickly and then RTB.

 

 

This is what the Viggen was designed for and its why it did not have any cannon :)

 

I love this, to bad there isn't very many videos like this available from the swedish airforce. :-(

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I love this, to bad there isn't very many videos like this available from the swedish airforce. :-(

 

Perhaps more can be found in "Krigsarkivet" (military archives)? Not sure if they have films or just photos and documents...

And there are probably a lot of films available within related "kamratföreningar" (veteran communities).

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Here is a video of SK60(a Swedish training jet) excising a typical Viggen attack maneuver where the plane is coming in at low altitude and then do a steep climb, roll over, then back again, fires of the armament quickly and then RTB.

 

 

This is what the Viggen was designed for and its why it did not have any cannon :)

 

nice video!

 

Is this the AJS-37 we are getting? The pilots seem to be sitting side by side in the cockpit in the minute 00:24. Is it the trainger version?

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nice video!

 

Is this the AJS-37 we are getting? The pilots seem to be sitting side by side in the cockpit in the minute 00:24. Is it the trainger version?

 

It is the SK-60, a trainer, not the 37

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Perhaps more can be found in "Krigsarkivet" (military archives)? Not sure if they have films or just photos and documents...

And there are probably a lot of films available within related "kamratföreningar" (veteran communities).

 

http://www.amf-arkiv.se/

 

You can order digital versions of old Swedish military film clips from here. Expensive, though.

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now the first sentence of the post make sense. Thanks for the enlightment, I have to say I am a Viggen illitrate :)

 

The Saab 105 / SK 60 was a twin seat trainer and also a light attack aircraft. This particular film is showing it in the attack version.

Pilot and navigator (student / instructor) are sitting side by side.

 

https://en.wikipedia.org/wiki/Saab_105

 

There was also a Viggen trainer called SK 37, but that one had the traditional configuration with the instructor behind the student.

Some SK 37 airframes was later reconfigured for electronic warfare etc.

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The Saab 105 / SK 60 was a twin seat trainer and also a light attack aircraft. This particular film is showing it in the attack version.

Pilot and navigator (student / instructor) are sitting side by side.

 

https://en.wikipedia.org/wiki/Saab_105

 

There was also a Viggen trainer called SK 37, but that one had the traditional configuration with the instructor behind the student.

Some SK 37 airframes was later reconfigured for electronic warfare etc.

 

That's what I read on Wikipedia. To find room for the instructor, they had to remove the radar. But then I thought, if it is the case then the instructor should be sitting behind not side by side.

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Some Viggen pictures I took at F17 at the air show 2004 when the 70 year anniversary was. The first picture has the SF-37 in front, the second is the JA-37 and then a front view of the SK-37 trainer followed by a side view and last a rear view of two JA-37 and the SK-37.

813445214_F17(1).thumb.jpg.d948d2a7d4ca2f770f249306d4676c89.jpg

1273453585_F17(2).thumb.jpg.45af4babda517eb96c7318278e5cdcd0.jpg

260632314_F17(15).thumb.jpg.cc1e2315e6f04fcd9f8b82545671ae0e.jpg

1109121988_F17(19).thumb.jpg.34d961efdab85ced93361c25f5bb97cf.jpg

968454304_F17.thumb.jpg.e72c8f4079a4062b7578922e4a752c70.jpg


Edited by hakjar

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Here is a video of SK60(a Swedish training jet) excising a typical Viggen attack maneuver where the plane is coming in at low altitude and then do a steep climb, roll over, then back again, fires of the armament quickly and then RTB.

 

 

This is what the Viggen was designed for and its why it did not have any cannon :)

 

Awesome video, we need that nasty looking black smoke trail in the sim once we get the weapons for the AJS 37

 

I'm quickly finding myself looking forward to this aircraft more than any other release since the MiG 21. Cannot wait to get my hands on it!

 

Some Viggen pictures I took at F17 at the air show 2004 when the 70 year anniversary was. The first picture has the SF-37 in front, the second is the JA-37 and then a front view of the SK-37 trainer followed by a side view and last a rear view of two JA-37 and the SK-37.

 

That was the last year of active Viggen service, correct? I'm assuming you still see some at authors these days?


Edited by Hook47
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I found a very interesting piece of text.

 

Its from a seminar that was mostly about the viggen.

 

With multiple of the guys working on developing the viggen aswell as some pilots and it has alot of interesting information.

 

It also contains mentions of other swedish fighters but the talk is focused around the viggen and there is alot of talk about the different systems and the development process.

 

Alot of it goes right over my head xD.

 

Sadly its in swedish =P.

 

Its 51 pages long (with 4-5 pages being blank and 1 page in english)

 

It focuses on the JA-37 Variant but alot of the stuff also applies to the AJ-37

 

Il go through it and if i find anything very interesting i can try to translate.

 

[ame]https://www.diva-portal.org/smash/get/diva2:13266/FULLTEXT01.pdf[/ame]

 

Third page is in english and is a bit of a summary.

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I found a very interesting piece of text.

 

Its from a seminar that was mostly about the viggen.

 

With multiple of the guys working on developing the viggen aswell as some pilots and it has alot of interesting information.

 

It also contains mentions of other swedish fighters but the talk is focused around the viggen and there is alot of talk about the different systems and the development process.

 

Alot of it goes right over my head xD.

 

Sadly its in swedish =P.

 

Its 51 pages long (with 4-5 pages being blank and 1 page in english)

 

It focuses on the JA-37 Variant but alot of the stuff also applies to the AJ-37

 

Il go through it and if i find anything very interesting i can try to translate.

 

https://www.diva-portal.org/smash/get/diva2:13266/FULLTEXT01.pdf

 

Third page is in english and is a bit of a summary.

I've translated some of the jucier parts of that for another forum. I'll just go ahead and paste them here.

 

A few terms:

- FMV is the Defense Materiel Administration, which was (and is) the government authority responsible for buying and developing all kinds of equipment for the Swedish armed forces. At the time when the Viggen was being developed, FMV still had a lot of engineers in house, which was considered important since it was thought at that time that in order to buy or develop a good system you had to know how it worked - they figured you had to understand the cutting edge technology in order to be able to write proper design requirements and adjust to technical challenges as they arose.

- JA 37 is the fighter version of the Viggen.

- AJ 37 is the strike version, which predates the fighter version by about ten years (entered service around 1970; the JA 37 around 1980).

- 35/"aircraft 35" is the Draken.

- 37/"aircraft 37" is the Viggen airframe in general.

 

My comments are in parentheses.

 

Please ask away if there's anything that seems unclear.

 

 

Gunnar Lindqvist (technical lead at FMV for the JA 37 project): In the early 1960's, work on aircraft 37 was initiated, and it was going to be a "main battle aircraft". That is, it was going to be a multirole, just like the Gripen is today and like aircraft 35 also kind of was, although with different versions of a common airframe. For various reasons, maybe because the Draken F existed and was equipped with decent missiles, the strike role dominated early on. That was sort of unfortunate, because it's the fighter role that puts the greatest demands on a combat aircraft. That meant a great deal of modifications had to be done to turn the strike version, AJ 37, into the fighter version, JA 37. A completely different targeting system using a pulse-Doppler radar was required, the aircraft's agility had to be improved and new weapons had to be introduced, some of which - like the radar-guided AA missile - were also based on Doppler radar. And in addition to that, further modifications or modernizations of other avionic systems. That added complexity, while at the same the aircraft's reliability had to be improved.

 

Many of these changes meant the utilization of digital technology, especially in the targeting system. But other systems were also digitalized, down to the engine control system. This was possible in part due to foresighted research in key areas in electronics, and also in part - of course - due to the inherent know-how in our aircraft industry. Maybe also in part due to a good working cooperation between the customer - FMV - and foreign government authorities and subcontractors.

 

[...]

 

Bengt Sjöberg (then at Saab): It's hard to entirely ignore the AJ 37 heritage. Because really, it was in the early 1960's that we pioneered the use of computer technology in an aircraft. And that was a time of "sturm und drang", I'll have to say. The ice was really thick in some places, especially among the aircraft engineers down at Saab. They were thoroughly suspicious towards electronics. I think they might have had some bad experiences a while back with aircraft crashes due to unreliable electronics. And a computer, that was something extraordinary, that seemed very unpleasant and dangerous.

 

But we did have some enthusiasts that understood the emerging technology. There was some experience with a transistor-based machine, SANK ("Saab's automatic navigation calculator", completed in 1960 and intended for missile guidance) that people had prepared themselves with and that we encountered in the beginning, when I came to Saab in 1960. It could fit on a tabletop at least, unlike BESK that took up a whole room. And we had some preliminary ideas back then, but we still couldn't fit it into an aircraft. But then came the development of integrated circuits. Viggo Wentzel and Bengt Jiewertz at Saab were all over those things and traveled around the US and picked up components straight from the labs. We could see the light of dawn in regards to being able to pack a decently powerful "generic calculator", as we called computers back then, into an aircraft.

 

And we tried to help in various places. I was thinking about how you could use a doohickey like that in an useful way and wrote up something about it. I talked a lot with our operations and tactics people about mission planning and what you need on board a combat aircraft. In general we believed early on that it was mainly about navigation and maybe some aiming aids, because we had done some work on gun sights and the like. But we came up with a long list of functions that we thought seemed important and essential, especially in a single-seater where we were going to get rid of the systems operator/navigator. And I wrote some documents about this.

 

There were a lot of different opinions about how much of this would be possible in practice. Our prototype was called NSK for a while, and a lot of people thought that stood for "numeric sighting calculator". But I thought it was better to call it "numeric combat calculator". Later it would eventually become CK 37 ("central calculator 37"). And we were fully occupied with getting even a single generic computer into the system. Some, especially at the aircraft electronics bureau at FMV, were of the opinion that we should have two computers - one that they would use for navigation and one that the weapons bureau could use for targeting and weapons - but I opposed that as much as I could.

 

Because the technology at that time had one great weakness, and that were the input and output systems. Analog-digital conversion, that was breaking new ground and we had to build from scratch. We thought that once we had gotten the signals into the computer there it was very easily possible for different functions to communicate with each other. But getting in and out of the computer was a big problem. And I remember when one of the computer engineers managed to run an analog simulator linked to SANK, that was a big deal. We didn't know if anyone in the world had managed to do that kind of link in real time, but at least in Europe I don't think there was anyone. But we succeed and started to believe in it, just to give you an idea just how tentative and fumbling everything was. Everything was new.

 

Later, we built what would become CK 37 with integrated circuits. Saab was a huge customer at the US manufacturers during the years when CK 37 was in development. The fact that it was one central computer wasn't just a device issue, it was also a philosophical issue. Because we gathered so much information in a central device that could be managed with software, we got a firm grip of all the important functions in the entire avionics system. We organically grew a personnel organization where, in a single corridor with everyone just a few steps away, we had full control over the development of the entire system. And that turned out to be very important for the future. We sort of inherited this central computer from AJ 37 to JA 37.

 

Those of you are interested can take a look in these pictures handed out. My memory isn't what it was and I have to look a bit at it before continuing.

 

Fci340k.png

(I guess I should translate this at some point)

 

Well, it's a small diagram showing the avionics system when we got started with the JA 37 project. In the center there's a pretty big central computer. It's not big because it's physically big but because it keeps then entire avionics system together. And these central computers, both in the AJ and the JA, they came to be filled with a lot of what we could call "pilot support functions". The cooperation with the pilot went from input data via the computer and to the presentation equipment, and from the pilot's control equipment to the various parts of the system. The data traffic was coordinated. One thing we learned from the AJ 37 was what a surprising number of logical operations that grew up during development. We re-did the instruction list in the CK 37 a number of times during the 60's. We had four separate prototypes before reaching CK 37.

 

All of this grew organically during violent but friendly altercations between us and the computer engineers. We discovered the importance and the computational load of various logical operations and mode selectors. We built those into the computer, which became very good at managing logical operations with a small memory footprint. And this central computer was the pilot's partner, you could imagine the pilot's brain working in parallel with the central computer.

 

If you look at the diagram, you'll see some boxes with doubled border, those are the functions that became computerized in the JA 37. Not just the central computer, which we kept in principle, but also for example the autopilot, which became the first operational digital autopilot in a combat aircraft. It was the result between a partnership between Saab and Honeywell. The basic system was a mechanical-hydraulic one, inherited from the AJ 37, and on top of that an autopilot that adds or modifies input signals in various ways. Then we also see that the atmospheric measuring system was also computerized, which was a big improvement because especially when you run back and forth through the sound barrier you get a lot of issues. We were sick of old mechanical cam discs and other miserable things in the old measuring devices, we could do better functionality in software. Then we also have some other sensors and some old purely mechanical instruments in the cockpit.

 

Additionally, a computerized or digital inertial navigation system was introduced in the JA 37, a good deed that was largely dependent on the people at the aircraft electronics bureau at FMV being proactive. Down at Saab the thinking went along the lines of let's save money, we did fine in the 35's with the old platforms. But this was a great improvement in quality. We had managed to create a "pseudo-inertial" system in the AJ 37 purely in software, via filters, complementary filters and such things. And that was very well suited to porting over to the better quality when we got a real platform for the inertial navigation. It turned out to be very important, both for the position reporting during fighter missions and for the quality of detail, the dynamic quality of all values shown to the pilot. The HUD in particular was especially sensitive since the symbols - like the horizon indicator, for example - had to be stable in relation to the outer world.

 

Then we have the electronic presentation, it was called EP 12 if memory serves. It had some digital solutions in a presentation generator and a "Digital Interface Unit" that talked to the radar (the DIU was made by Hughes in the US according to a Swedish specification and named such because of export restrictions; it was also called a "scan converter" and transformed the polar coordinates from the radar data into rectangular ones that were used by the cockpit radar display). The radar also introduced some computers, which you might hear more about soon. And all of this meant a lot, both signals processing and general control of various functionality via software. The HUD we inherited from AJ 37 and improved. There were some issues with the field of view, but some of the engineers mucked around with it and got double reflex glass which improved the FoV and made the thing more manageable. Then, of course, we have the radar display. The guys in Mölndal and Kista (SRA and Ericsson, respectively) hacked up some new technology with some kind of digital processing of the radar data, which made it very simple and nice to overlay symbols on the radar display in the same way that you displayed radar returns and tracked targets.

 

R9U0Vph.jpg

eQQnxAb.png TlL95Bs.png

 

The radar display is in the center of the cockpit front, behind the stick. If you look to its right and slightly upwards, there's a new indicator screen there that wasn't there in the AJ 37. That's the tactical indicator, TI. There was a lot of gargling about that. The aircraft electronics bureau at FMV and SRA (Svenska Radioaktiebolaget; "Swedish Radio Company, Ltd", acquired by Ericsson in 1983) had agreed that it was entirely possible to add another indicator screen with the same kind of info as the target indicator (MI). But they didn't really know what to use it for. They started by drawing something like a course indicator for showing the bearing to the target. The air force test center's test pilots were really skeptical and wondered what the hell they were gonna use that for, and went "give us an ordinary mechanical course indicator"!

 

But we had a guy at Saab that had previously been an air force air combat controller. And he was very excited when we started talking about drawing maps on the tactical indicator and was like "it should be possible to use this for mission parameters in a better way and show some targets and stuff". He was all over that idea and wanted to combine the target display with some kind of simple map. Since he was an air combat controller he was able to convince the controller people as well. We started working on some suggestions. SRA started thinking about electronic map generation and came up with what would later become an ELKA (basically an abbreviation for "electronic map"). However, when we got to the time to make the decisions, we got a document from the test pilots that said that they by Jove didn't want no tactical indicator, it should be thrown out of the system. They wanted a bigger mechanical course indicator. But down at Saab we all agreed that the tactical indicator would be a big step forward and FMV agreed with us.

 

In the end it was decided that the tactical indicator was in, and that turned out to be one of the big improvements in how data was presented to the pilot. Among other things, this was because until then, we had used what was called "direct combat control" on the 35's, that is to say all commands and courses and altitudes were decided and calculated on the ground and transferred to the aircraft via data link. But this new technology opened up a world of possibilities to do what we called "indirect combat control", in part due to a good inertial navigation system and in part due to this tactical indicator. But the air force chief of staff, I think it was the choleric man Gösta Tullson, he forbade us to do anything related to indirect combat control at all. We ignored him, though.

 

Together with the air combat control people we programmed the computer with all of the different data link messages and did all of the ground work for this, so we could transfer everything the ground installation knew of the target's position to the aircraft. And up there we had the complete freedom to calculate intercept vectors and target bearings and such things ourselves. This eventually turned out to be very important functionality in the JA 37 and all of the hostilities were forgotten. But to throw the test pilots a bone we had to extend the panel above the tactical indicator, as you can see in the picture of the cockpit. We had to make a bump on the right and take some space from what had previously been holy, namely the field of view over the nose during landings and low altitude flying, in order to put in a mechanical course indicator that resembled the one in aircraft 35. Because the 35 was holy to our fighter pilots back them. But that course indicator really wasn't necessary. The tactical indicator had the same information plus a considerably better overview of the situation, a map, targets, friendly aircraft and so on. I've met fighter pilots who wondered about this mechanical indicator, because they had hardly looked at it. For symmetrical reasons we had to raise the panel on the left as well. Suddenly the field of view over the nose wasn't so important anymore!

 

Well, that was a long parenthesis about the tactical indicator. There's one more thing to say about this, though. The communication in and out of the central computer, between all of the computerized subsystems, it was done point-to-point using serial binary links. And that was a huge leap forward, because they were programmable in both ends. We could grow flexibly as our knowledge grew, we didn't need to change the hardware. What remained of analog things usually entered the computer world via a conversion unit that turned the analog data digital and then let it into the central computer. The communication with the combat controllers on the ground was of course digital. Digital tape recorders were also an important thing that SRA developed while working on various presentation screens, and they came to be used a lot for training. You could record everything that was displayed to the pilot and show it to them on the ground after the mission, and they learned a lot from that. This was used more and more as the JA 37 was developed. Other tape recorders were used for maintenance and testing.

 

[...]

 

 

Moderator: Bengt, I have a question. Early on you hinted that it was hard to get traction for this idea with a central computer. Was it some big isolated thing that led to you guys getting approval for it, or was it more like a gradual acceptance of the idea? And who were the key people involved in this?

 

 

Bengt Sjöberg: Well, we had some enthusiasts down at Saab. Then we had a lot of support from FMV, the aircraft electronics bureau and also the weapons bureau. Despite those two being kind of at odds with each other, or maybe more like competing with each other in some respects. There were some people up there that tried to be at the cutting edge of technology and cut in at certain critical points. The big skeptics were down at Saab. The closer to the aircraft building and sheet metal bending you got, the more contrary they were. They saw all avionics as a complication. They were used to Saab just making aircraft and that FMV ordered empty spaces that they put their secret black boxes in. And who was responsible for the entire system, that's beyond my ability to judge.

 

 

Ulf Frieberg (test pilot): Well, there's been some criticism flying through the air here. If we consider what kind of people could help with with development, I saw with more and more clarity over the years that there were serious problems with the test pilot training, with the different specializations available. There were those who knew the aircraft and all sorts of ergonomic things very well. And there were those who were starting to tentatively look at avionics systems. But not even at Saab they weren't listened to very well. And that's something I'm definitely remembering for future generations. But then I had the great privilege to join those who had been involved since the start of the AJ project. And when we got started on JA people were suddenly all ears from the beginning. One big obstacle was actually the Draken, which was a very good aircraft for its time. But in terms of development it was a surprisingly bad aircraft. If the pilot got into a combat situation where decisions made in the matter of a second decided if he was going to live or not, he was presented with choices that he would need time to consider. Some of our people saw that, some didn't. And that was the big dilemma in JA 37. Those of us who had been involved in the AJ 37 development were considerably better prepared for discussing these things.

 

But when we saw Bengt Sjöberg's vision about systems and improving pilot efficiency that was met with a great deal of enthusiasm from both sides. We saw the possibility of improving pilot effectiveness a great deal, you could not just do things but do them during very high levels of stress. And, like I said, there were all to few that had the possibility of developing themselves through the insight of a superior, instead there were some individuals that educated themselves, and of course this resulted in conflicts. But these things were irrelevant considering what actually happened. Bengt came along with his enthusiasm and I needed to support him. Unfortunately, at the air force test center there was a faction of very talented guys who knew the J 35 very well and really wanted to use it at its full potential, which was far above the level most regular pilots could get to. That meant it was one hell of a job to get everyone on board. I guess used some tricks, but that's probably forgiven today.

 

As an example we can talk about this little mechanical course indicator above the tactical indicator which Bengt mentioned. It was absolutely nothing until we suddenly realized that SRA had improved that map above a certain level. And suddenly everyone agreed that the tactical indicator should be in. We had an experimental model installed in the simulator at an early stage and the entire mission overview was ready in a second. I mean everything was clearly laid out immediately! But if you wanted to get the same overview through conventional instruments you had to look in a lot of different places and gather the information up yourself. That was a big step in convincing the test center and this faction. Without this development step you'd have to be continually keeping up with new directives and commands from the ground. But with this tactical indicator, that wasn't necessary. The pilot was far, far ahead of the data link directives and he was aeons ahead of the air combat controller on the ground and could see the entire situation continually and correctly. I've never heard any pilot saying he actually used this relatively expensive mechanical course indicator.

 

 

Kim Bengtsson (computer engineer at FMV at the time): Well, I can relate a ridiculous anecdote. Bengt was talking about integrating the inertial navigation unit. Originally it was completely analog, that unit, and had the software running in the central computer. It was FMV that bought the inertial navigation unit and paid for software development for it in the US. It worked very well. Then Kearfott came up with an improved unit that had a built-in computer, a pretty powerful machine, so we could move all the inertial navigation calculations to that computer. In theory, that is. But then we ran into the problem of how to replace the unit in the test aircraft, which still had the inertial navigation program running in the central computer. In order to make that transition smoother we let the inertial navigation unit's computer simulate the old analog inertial navigation unit, so we kept the same interface but without actually making meaningful use of the computer in the new digital unit. As far as I know it still worked that way when we scrapped the JA 37's. We sometimes talked about how possible future researches would wonder what the hell we were doing.

 

I also have something to add regarding what Bengt said about direct vs indirect combat control. There were a lot of big discussions about that. From the start we were more or less forced to make JA 37 simulate and act like a J 35. And that was really stupid, a lot of people were pissed off about it. But when thinking about it in retrospect maybe it wasn't so stupid after all, because we had one leg firmly on the ground in the connection to the ground systems, and we adapted the aircraft to that. And after that we could make the transition to a more complete combat control system in the aircraft. At that point we had gotten to know each other, understood each others problems and so on. So maybe it was a bad thing that turned out to be good in the end.

 

 

Gunnar Lindqvist: The Draken had a complicated targeting system. It wasn't just a radar, but also an infrared sensor that unfortunately wasn't too reliable. And this made it pretty hard to switch between different working modes. You took information from one sensor and combined it with information from another and there were a lot of different cases that made it pretty hard on the pilot. But under not too stressful circumstances I maintain that it wasn't such a bad system. In particular it wasn't bad compared to what everyone else had at the time. You shouldn't compare the 35, which dates back to the late 50's, to aircraft introduced a decade later.

 

When it comes to the central computer, its origins are further back. There were a lot of discussions regarding if aircraft should have one or two engines and if they should have one or two crew. And most of our strike aircraft have been two-seaters, but some that have been modified from fighters have been single seaters. That was a big issue during the development of the AJ 37, if it was going to be a single pilot in it, or a pilot and a systems operator. But finally the faction that wanted a central computer instead of the operator won. That was a risk, but it turned out to work well. But I want to remind you that we have aircraft called JAS 39 B and D, and those are two-seaters. Sometimes you need two crew.

 

[...]

 

Leif Åström (strike aircraft squadron commander at the time): I'm going to back up a bit and talk about what Gunnar mentioned, taking the step from flying two-crew aircraft to single seaters and the worries we had about that. At that time I was in a strike squadron and flying the Lansen and experienced this change personally. In the Lansen we were dependent on having a navigator/systems operator in the rear seat to be complete as a leading aircraft. It wasn't certain that all aircraft had one, only some did. We were also dependent on having a radar, and not all aircraft had one of those either, so only some aircraft could lead. If you were flying with the squadron commander he was usually in charge of one group while his second-in-command led the other. Really, those two were the only ones who were fully equipped. If you lost one of them, or even worse both, we were very ill prepared to continue the mission. In practice the unit lost its decision making powers. Happened a lot. It was the operational consequence.

 

From a pilot perspective the obvious thing was that we had a system that was based on top-down control. The commander led, the rest of us hanged on to his wingtip and followed. And that was an organization that motivated the flying personnel about as well as you'd think, of course. When we switched to aircraft 37, a single seater, where every aircraft was fully equipped with radar, navigation systems and so on, we suddenly had the capability that anyone in the unit could take over command at any point if necessary. It could be because we lost someone or maybe the guy taking over had the best view of the situation, or whatever reason. And that, I'd say, was a very important turning point for us. We now had an equipment system that let us switch from a top-down organization to a management-by-objectives one. We could use the squadron's intellectual capacity in a completely different way. So this was a very important step in many ways, not just important technically but also important operationally.

 

If we then look at the JA 37 and the tactical indicator it was basically the same thing. Earlier, it had been the air combat controller on the ground that made the decisions and controlled his fighter aircraft with data link directives. With the introduction of the tactical indicator, the air combat controller's behavior changed. He became the one that served the pilot with information so that the pilot had a better view of the situation, a better basis on which to make decisions. And then air combat controller wasn't the bottleneck he had once been. Not to say anything negative about the air combat controllers, but if you have a demanding decision making role, you can only manage a certain number of fighters at a time and the air combat control was often a limiting factor. When we started serving up information on the tactical indicator that limitation mostly disappeared, and at the same time we started getting pilots who were used to making their own decisions. The pilot's task was to make decisions based on what he saw on the tactical indicator, and we created more decisive pilots, pilots that were better prepared to handle the unexpected and better at reacting to quick changes. So I'd say both of those changes were fortunate.

 

 

Lennart Alfredsson (then at SRA): You're talking so much about that tactical indicator, but I guarantee that back then when you were going on about it, there wasn't a chance in hell to actually make it work. We had no working solution. Map instruments in aircraft did exist, optical ones. Ferranti had implemented one, it was based on a 35mm film running around like crazy, rotating and whatnot. Then there were those who built small extra ports in the back of cathode ray tubes and projected the map on the back of the phosphorus layer, it was white so you could see it, but it had to be pretty thin to be visible. Since we didn't have an aluminum backing we'd lose half the luminance if we did it that way. So we didn't really have any good way to do it. On top of that our project lead didn't want the thing to be too expensive.

 

Well, we decided we were going to try with a digital tape deck, and the ones we had could hold about 14 megabits unformatted. But it took five or six minutes to run the tape from one end to the other and that made things difficult. Sweden's a very oblong country so we had to split the tape in segments. Possibly this "Raymond Tape Unit" we had could work, it was in use in aircraft but not for this purpose. So we really didn't have any solution that would let us draw a decent electronic map. We worked for over a year with trying to find new solutions that we eventually discarded, further new solutions that we also discarded and so on. For about a year. I had a colleague called Stellan Nennerfelt, many of you knew him. One Friday we went home and suddenly we both had an idea. And we both rushed back into the office and said "I have the answer!". We had the same solution, the two of us. Exactly the same.

 

Simple, but not something you come up with immediately. The time for a presentation on the tactical indicator is about 20 milliseconds, and it refreshes all the time, so you have to do everything in 20 milliseconds. We callously stole two milliseconds and said that two milliseconds, that's what we got for the map. But no longer. We wanted a lot of other things on the indicator as well, after all. And then we made one long chain of segments, starting in Sundsvall. Ordinary seven-segments, sometimes you could jump a bit further and sometimes a bit shorter. Sometimes it was silent and nothing was drawn. We started in Sundsvall and just followed the chain as fast as humanly possible, along the coast, up rivers and down rivers and up to Umeå. Along the entire Finnish and Norwegian border and the entire way down the western side of the country, some islands in and out and up and down. And when we got to the place where the aircraft was, we stopped and went segment by segment and illuminated the entire map within the area the indicator showed. And when we got to the far end we sped up again.

 

This actually worked, this was something you could do in a small country. Hughes Aircraft Company, our partner, they couldn't do it in the US, it was too big. And when we tried with Australia when we were going to travel down there, that didn't work either. Sweden was just small enough. Those of you who were involved back then will remember that there was always a demo map over Scania (southernmost part of Sweden). That's the perfect place in Sweden to draw an electronic map of. Try it up north and see how that works out for you! There's one single building! And that building was put there on the map just to make it possible to figure out where the hell you were.

 

But the electronic map turned out to be cheap, actually. The entire system was 4000 four-bit words, 16000 bits total, and that covered the entire country. You can imagine how much that is. 16000 bits is about two kilobytes. Saab's travel expenses form is 65 kilobytes today, and that's before you fill it in. It wasn't easy to get this electronic map in, really, it took us over a year to find a workable solution.

 

 

Ulf Frieberg: But there's no doubt that once that step was made, all resistance was gone.

 

 

X4JuMVc.gif

What the tactical indicator actually looked like. The aircraft is the small triangle in lower center; it's heading south by southwest over the island of Öland. In the lower right corner the aircraft weight (VIKT) and something about the angle of attack (ALFA - possibly max allowed AoA in current configuration?) are shown.

 

 

Lennart Alfredsson: We had simulated the electronic map earlier in a simpler way in aircraft 35, or maybe it was in 32 Gamma (32 Gamma was a modified Lansen that was used as a flying testbed for the JA 37 radar and some other avionics). We had the resources, we could actually fly these experiments. In combat aircraft, too, unlike the yankees who got to do it in transport aircraft early on.

 

 

Hasse Olofsson (at the aircraft electronics bureau at FMV): I worked on the presentation system and related developments directly. What I think was a major factor in all of these parts was actually our experimental and testing activities in parallel with the regular development. Without those we would never have dared to push as hard as we did. You mentioned 32 Gamma and that's where most of the work was done. It was the same with the HUD in JAS 39 which was the first of its kind in the world. We've had an incredible experimental and testing environment.

 

 

Bengt Sjöberg: I thought since we were discussing the usefulness of the tactical indicator I should jump back a bit and point out a bit of icing on the cake, if you will. More specifically the fighter-to-fighter datalink that more or less came skidding in on a banana peel at some point. They were working on a project called A 20 (proposed new low-cost strike Viggen version with the capability of carrying more and heavier weapons) and couldn't afford to put a radar in every aircraft, some development work was done more or less by feeling and then the entire thing was cancelled. But one thing they did come up with, namely that if only some aircraft had a radar then you could make those transfer their radar data over a radio link to their squadron mates. They squeezed a solution out of the radio system that made it possible to send that data during idle periods. The aircraft with a targeting solution could transfer both the radar image and the targeting solution to others. From this the real fighter-to-fighter data link grew and was later integrated on the JA 37. We ended up with outstanding cooperation capabilities within a fourship, through this datalink and the tactical indicator. And that functionality JAS 39 ended up inheriting as well.

 

 

Leif Åström: I have a few things to add to that, it might be worth commenting on from the user's perspective. The first step, the introduction of the pulse-Doppler radar, that marked the end of the days when the silent men of honor rushed along between the treetops of pine and fir and nobody could see us with radar. We could hide pretty successfully from the 35's back then, but with the Doppler radar that came to an end. They dug us up and saw us down there too. On top of that, when the fighter datalink came, when I got a radar warning from one direction, suddenly another one appeared from a different direction and had me boxed in without me having discovered him at all. That was a very unpleasant development for a strike pilot! It was a very big step forward.

 

Initially, this was something we were pretty careful with. There was a lot of secrecy around the fighter datalink, it was nothing you could talk about carelessly, it was some years before we showed it to anyone. And what I was actually going to talk about was the first time we showed it to an international audience. It was at the 6th air wing and we had a visiting squadron of Jaguars from the UK. It was kind of a special visit, we met up on a Monday and gathered up as usual in the briefing room and presented ourselves to each other. We talked about what we were doing, about our aircraft, such things. Their squadron commander did the same thing for their side. They had their wartime assignments in Norway, as it turned out. That was interesting. But then he said something that was pretty surprising and very un-British. He said "well, I really gotta ask you one thing I've been wondering about. Why on earth are you, in this small country with a population about London's size, developing your own combat aircraft for silly amounts of money when you could just buy off the shelf, from us for example?" And that was pretty hard to answer then and there.

 

But then they got to follow us for a week. They got to ride in the 37, see its performance for themselves, performance that wasn't just marketing but actually true in real life. And they got to see some other things. At that time, we showed - for the first time, as far as I know - the fighter-to-fighter datalink. They got to see it at the 13th air wing in Norrköping through the UTB (the UTB was a recording and presentation system mainly used for training; it recorded almost everything that the aircraft showed to the pilot, as well as pilot input and some tactical data, and the entire mission could then could be presented - including pausing and rewinding - and analyzed on the ground in what basically amounted to a simulated cockpit) and we noticed how they grew silent. They started whispering among each other, talking and pointing, and it was obvious that this was something that had impressed them. And the week went on and the time came for them to go home. And the same squadron commander stood up again, and he was a bit embarrassed, because remembered what he had said that previous Monday. He hemmed and hawed for a little bit but then he finally got to the point and said "I remember what I said last Monday and well, now we've seen some things here".

 

Then he talked about the experiences I mentioned and he said "You should know that right now we're discussing if we can afford a system like this in our next aircraft, the Eurofighter, and in that case how many of the aircraft we could afford to put it in. And then we get here and see that you already have this system operational, and at a fraction of the cost we're going to spend on it. Keep building aircraft, it seems like a good idea!" He actually said it, just like that. I think that might be some kind of indication of how valuable that system was, because sometimes it's hard to see internally how far you've gotten. This was in 1985, I think, and only today are other systems like this starting to become operational. Sometimes we've been far ahead without knowing it.

 

 

Kim Bengtsson: Yeah, I just want to relate another anecdote of how the datalink was perceived. I remember the first time the test center pilots were up and flying with it and when they landed they were like, "This is goddamned awesome, now we can turn those guys down in the cave off".

 

 

Moderator: Who were the guys down in the cave?

 

 

Kim Bengtsson: The air combat controllers. But maybe I shouldn't call them that here.

 

 

Bengt Sjöberg: Well, "turning the guys down in the cave off" might be a bit of an exaggeration.

 

 

Kim Bengtsson: Well, yes, slightly, but that was the general feeling you got.

 

 

Bengt Sjöberg: These days though you want encryption and ECCM on everything, so it's not so easy to detect and identify what's flying around up there. You can out yourself by sending out a bunch of signals.

 

 


Edited by renhanxue
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Part 2:

 

 

Moderator: Well, we've talked about the system, but I was thinking we should focus a bit. We've already talked a bit about user interfaces, but maybe there are more things about the machine end of things that we'll want to cover?

 

 

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The target indicator display in the JA 37, in its original incarnation.

 

 

Lennart Alfredsson: Yes, well, you can't avoid talking about user interfaces when you've been at SRA working with displays for a significant part of your life. In the very first solutions for the JA we used parts from the AJ, of course. In the AJ you could turn the reflex glass for the HUD up and down, but Ulf Frieberg didn't like that, he wanted a different solution. And we did end up with another solution in the end.

 

In the AJ the central display in the cockpit was a round thing with an outer diameter of 110 mm (4.3 in) and on that an ordinary PPI was shown. The useable area was about 100 mm in diameter. We couldn't go back to the system we'd used on the 35, because there the radar returns were "stored" with simple electroluminescence that showed a "memory" of the pulses, and the visibility wasn't great. We wanted something with much better visibility than that, and so we started off with the AJ's indicator screen.

 

The first thing we tried was drawing a regular B-scope. An analog B-scope has pretty big distortion errors at the bottom of the display, things float out towards the edges no matter what you do. We implemented some B-scopes and showed them on the indicator screen we had then; as Hasse Olofsson mentioned we had a pretty good amount of money to use for various related development. But the result wasn't very good, nobody at all thought it was a sound idea. Instead we returned to the solution they had in the US, which was based on a "scan converter", which meant you took the radar input signal, put it through a special cathode ray tube and then you could read a signal suited for presentation in the other end and show that on a display. You needed an extra glass tube, about 40 centimeters (15.75 in) long with a weird double anode in the center and two electron guns, and this was supposed to fly.

 

I know the yankees did that. We had steady contacts with Hughes Aircraft Company. Their solution was originally part of a system called CORD (Coherent On Reception Detection, a precursor to fully coherent systems), which some of you might remember. And that was no good. It was nothing. Nobody at FMV, especially not at the aircraft electronics bureau, found that particularly attractive. But then, in the morning of May 8, 1968, my colleague Acke Axelsson called me and said "I'm back from my visit to Hughes and I have something to tell you". And he came to me after lunch. He told me there was a new component, a linear shift register, which was a thousand bits long.

 

A single component that could store a thousand bits, that was something that hadn't existed before. We got started, Acke and I, and we kept on until nine PM and we drew and drew and drew. We built chains of these shift registers. We needed about a hundred thousand bits (~12.2 kB, about two thirds the size of the text of this post) to make a B-scope. And we really wanted the possibility of storing and "aging" the radar returns. On top of that we had the problem that while the radar had a refresh rate of about 1 Hz, the presentation system ran at a refresh rate of about 50 Hz. Thus we had to be able to present the information continuously while reading in new radar data and removing old information from the system. It actually took us nine hours until we were convinced that it would work. From that day, when Acke and I went home at about 9 PM, the old solution for the central indicator screen and everything behind it was completely dead. There wasn't a chance we'd even get the idea of getting that back.

 

We had solved all of the problems. In the central indicator on the AJ there's radar integration pulse by pulse, there's brightness control, there's memory, there's tons of things. Everything was a huge compromise, an extremely fine balance of voltage potentials that controlled various grids and cathodes in the system. It was all gone, we could divide and conquer. The radar did its own thing, it delivered a neatly packaged video signal. We could draw symbols separately, we could solve the storage of radar pulses separately, we could solve the brightness control separately. Everything came together in a single evening. And there was no talk of going back to any other solutions.

 

But it was hellishly expensive. When we got started the military variant of these shift registers were eleven bucks per bit. Eleven bucks per bit (in today's dollars; I adjusted the original Swedish numbers for inflation and converted to USD). And we needed quite a number of them. We were talking millions, and there was no way we could spend that on trials, so when we built an experimental system we used the civilian ones and they were about $2 per bit. In the end when we had to quote the cost for the system the military variant had gone down to $2.2 per bit as well, so that was 220,000 dollars for that one component. Everything, the entire system, five boxes of electronics, was $287,000 in all. It wasn't easy to convince the management that we should blow $220,000 on a single component.

 

Anyway, we built these things. From that point analog wasn't on the table, everything was purely digital. This turned things on their head, we could process targeting data, we could do all sorts of things. And then Hughes had another flash of genius. They suggested we should switch to drawing the targets character by character as ASCII. What we did was we chose only the targets and marked them, which meant the memory footprint was greatly reduced. In the system we had the capability of showing 128 targets. That was all. We implemented "aging" so we could see the target tracks, we could save two, three, four, five or six, as many sweeps after each other as we wanted. So we could see where the targets were going. We could draw their course vectors directly on the display. But that information might not be all that easy to interpret correctly when you're going really fast yourself and on top of that you have to take the B-scope distortion into account. So then we implemented compensation for the aircraft's own movements and for the B-scope distortion. More or less, the tracks you saw on the display were a pretty good representation of how the target was actually moving in relation to the aircraft's "track-up" in the system.

 

May 8th, 1968, that was the big turning point for us at SRA. The symbols weren't a huge problems, we had those in the computers, we did a lot of experiments with those, we tested all kinds of things. It was obvious that computers and digital was the solution. But for the radar it was on that day that we received the information that solved everything. Sometimes you're in luck.

 

 

Some of the JA 37's original displays in action; the tactical indicator is shown at the linked time, the HUD and the target display come up a bit later. The arrows are friendly aircraft, the # signs are targets.

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Goran Tode (visitor at the seminar, worked with strike aircraft ops at the air force HQ at some point): I have a question, let's see if I can formulate it decently. I'm rather impressed when I hear you talk about these things, how you took advantage of new ideas. I wonder if there's something special with corporate culture when it comes to aircraft in particular. In that you take advantage of all opportunities, and that it's so dynamic, it changes all the time. Many years ago I got take a ride with the navy while they were hunting subs, and I took a look at their command and control system and I understood immediately why they never caught anything. It had brass tubes and whatnot. No, I mean, through the aircraft, through high-tech and the danger and everything, you immediately get to know if things are good or bad in a different way than you do at sea. And if we look at administrative control systems that's even worse, then you never see anything until it's too late. Does anyone want to comment on this?

 

 

Lennart Andersson: Well, it's a good thing. In my world there's always been positive and negative things. If we at SRA had some good ideas that we believed in, that we though we could do - and it was certainly the same at Ericsson in Molndal - FMV was always up for it. Sometimes you had to advance some money but it always came back in the end. We had lots of opportunities, we had it better than the researchers at any university. However, in my opinion, what was kinda wonky was the corporate executives, you couldn't trust those. At all. When we got started with digital technology at SRA, which was about 1964 to an order of magnitude, the circuit boards were huge clunky things. And then a directive from the execs came down, saying that digital circuits were for the development division only, and those guys were on the sixth floor somewhere far away. The rest of us were not to work with integrated circuits. They forbade us to work with these things, but we didn't give a ****, we didn't take that seriously.

 

The next big thing was when Saab got started with computers, or calculators as they were called back then. There was a directive from Marcus Wallenberg himself to all of Ericsson and SRA (Wallenberg was one of the big owners of both Ericsson, Saab and SRA; he was the chairman of the board at Saab at the time) that we could not do anything with computers. Period. And of course we didn't, we called them program units, and in Molndal they called them control units. But they were surprisingly computer-like, I'd say! Anyway, those were the orders, we were not to work with calculators. When new things show up the execs have to let them out all over the business and let everyone use them, no restrictions, check them out and poke at them. There's always someone who has an idea somewhere.

 

 

Moderator: Can I add something to that? You'd think that the universities would be on the cutting edge, and I became a professor in 1965. If we were to purchase a computer at the university, it had to be approved by the computer committee, the computer central. And they were kinda like corporate execs, they said we couldn't get a computer of our own. But then we called it a process control unit instead. And then it was fine to buy one. So it's not just the corporations that has management like that, the kind of progressive places called universities suffer from that too. Sorry, I shouldn't talk so much myself. Gunnar.

 

 

Gunnar Lindqvist: Well, regarding the skepticism against electronics. I suppose I should point out the background information that in the case of aircraft 32 and 35, the electronic systems were heavily delayed and couldn't keep up with the aircraft deliveries. That's why the aircraft engineers a bit doubtful about newfangled things. At Saab they had a new systems division and the guys who "banged at the sheet metal", as someone irreverently put it, wondered what these systems people were doing. When it came to delivery deadlines the avionics industry wasn't as mature as the sheet metal benders. When we were getting started with aircraft 37 we got a directive from the commander of the air force, that we couldn't put a single new device in the 37, it was all to be stuff from the 35. This was changed later but the IFF unit remained. One of my coworkers said it was only interesting to museums and souvenir hunters. That was some background regarding the skepticism against electronics. As always, it was about risk management.

 

I almost forgot the most important thing I was going to say, the issue of the customer's knowledge compared to that of the provider. We at FMV had the mindset that we had to have very good engineers with a vision of the future, who could communicate with the people in the industry, our suppliers. The Royal Academy of Engineering Sciences conducted an investigation in the 70's where they found that one of the reasons that Swedish industry had been so successful was the relationship between customer and supplier. And that wasn't just between FMV and Saab and Ericsson, but it was at least as important between, for example, Vattenfall and ASEA Atom (nationalised power company and nuclear power generation respectively), and between SJ and ASEA Traction (national railways and train builder respectively). And certainly not the least, Televerket (the national telephone administration). The national telephone administrations in Norway, Sweden and Finland came up with a standard for cell phones. That meant that the Nordic countries were more than a decade ahead of other countries in that area. But in today's investigations made in the armed forces they find that the engineering people at FMV are an unnecessary double competence that just bumps up the requirements and that those engineers shouldn't be there.

 

 

Bengt Sjoberg: When it comes to working methods maybe I should direct some attention to the working groups that more or less grew up during the time of the AJ 37. For example, when it came to to adapting the JA 37 to the needs of the pilots, we made sure that was a more formal working group. It was called the PM group and it consisted of representatives from Saab, FMV, the air force test pilots and Saab's test pilots, as well as some people from Molndal - the radar was important - and some presentation guys from SRA, usually one or two from each. And we had some pretty intense meetings. First we had some smaller groups meeting up to discuss every single system function, and then we had more formal meetings at regular intervals. Other than the PM group there was also, for example, a radar integration group, called Malinmatningsgrupp 70, MIG 70.

 

 

Lennart Alfredsson: We weren't allowed to call ourselves 37. MIG 37.

 

 

Bengt Sjoberg: No, and this was in the early 70's. I think we met every two weeks for several years. We alternated the place where we met, and here we benefited from Sweden's limited size, we could always call for a meeting just a day or two in advance if we had to. We could gather the knowledge that existed within our borders. Then we had a communications and combat control group where the corresponding people at FMV were members. The pilots had their say, we always had excellent cooperation with the test pilots. Some of them were very good a understanding us engineers and could describe details they observed during the flight, as they were observing it. In a single-seater aircraft it's not easy to hitch a ride and look over the pilot's shoulder. Then we got good simulators and there we could have intense discussions.

 

When this PM group came with a recommendation that was sometimes a pain for the project management, because who the hell was responsible for what in this group? Who was in charge of the economic issues, and so on? But we always replied that we were just issuing recommendations. Then it was up to every project manager to count his own purse and for the project management in concert to decide. And it was very hard for the project management to go against these recommendations, because there was a lot of power behind them if you look at who was represented in these groups. The way the contracts were written for the 37 was also pretty good for cooperation in an area of technology where the understanding of things was constantly growing. Because the man from FMV could go home and talk to Gunnar here, and come back with a small bag of money, most knots were untangled. FMV had some resources in reserve.

 

Since we could talk freely between the industries it worked very well. If we didn't like something you could always call up Acke Axelsson or some representative at FMV and say "We're having some trouble with this detail, can't you go talk to the guys in Molndal about it?". And after a while the problem was usually solved. Usually the FMV man in question had a small bag of money with him because he saw the long-term economy in getting a better system, while the industry was working with a more limited perspective. But, well, you didn't win any popularity contests with your bosses at Saab because of all the suggestions we came up with. Because it cost money. But there was a solution for that in the 37 era.

 

Those solutions weren't there when we were developing the JAS 39, there we couldn't criticize each other in front of FMV. I couldn't say that now things are ****ed at Ericsson in Kista, they're completely stuck. We shut up about that. We didn't tell our friends at the aircraft electronics bureau. I really do believe though that it was basically a good way to write a contract for the 37, and these working groups worked very well. Many solutions and ideas grew from there. The PM group, for example, just decided many hundreds of details that we flat out sat down and signed off. No project manager could even be bothered to get up to speed and understand the details, so it became as we had decided if the costs didn't skyrocket too much.

 

 

Lennart Alfredsson: There was one downside to these contracts, and that was that it was very easy to change, add or remove things during development. And nobody thought about the upcoming series production. We added a small casing here, we laid a cable there and there was some of this and some of that. The electronic map and the other things weren't free. Things got added here and there. And then when we had to come up with a quote for the series production it turned out to be pretty expensive compared to what we had said originally, we had gotten a gradual increase of costs in this system, at least at SRA. They wanted to get rid of that in the coming discussions about JAS, and so they did and unfortunately they did it way too well. There they connected the development to a limited series production run and there were no changes allowed for something like seven or eight years. That was sort of unfortunate. But there are downsides to any contract.

 

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Bonus, a highly interesting 1983 issue of Ericsson Review, which covers the design of the JA 37's pulse-doppler radar as well as some radar theory in general:

 

A bit technical at parts but very interesting ;)

 

The other parts are also interesting. I don't think there are many that understand how innovative the AXE phone system was for its time.

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I'm going to be beta testing the Viggen tomorrow, I can't wait!

 

(a Saab 9-3 Viggen but that's pretty much the same thing, right?)

 

It's been out of Beta for quite a while, I last drove one in 2001....still the only car I ever broke on a test drive. :doh:

 

Lets just say that the shift-linkage wasn't terribly durable or amenable to powershifts....how else do you keep a laggy, single-scroll turbo four on boil for acceleration runs? ;)

 

And mind the torque steer too! That engine has a healthy mid-range that paired poorly with FWD.

 

-Nick

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It's been out of Beta for quite a while, I last drove one in 2001....still the only car I ever broke on a test drive. :doh:

 

Lets just say that the shift-linkage wasn't terribly durable or amenable to powershifts....how else do you keep a laggy, single-scroll turbo four on boil for acceleration runs? ;)

 

And mind the torque steer too! That engine has a healthy mid-range that paired poorly with FWD.

 

-Nick

Shame you had a bad experience, I loved driving this one. The owner put in a rear sway bar and new steering rack to help with the torque steer. Very forgiving clutch. Didn't stall it once despite only have 3 hours or practice on an old truck!

 

I was a little disappointed that the RM8B turbofan couldn't bring her up to Mach 2.1 as advertised. And where are the weapon systems? :lol:

 

hLgvxcg.jpg

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Before the AJ 37 Viggen was the A 32 Lansen, which had the same role. One of the last squadrons to fly it was "Filip Blå" at the 6th air wing out of Karlsborg. Here's a 1975 Super8 recording of some of those "silent men of honor" (with magnificent facial hair), the ones one of the test pilots were talking about in the JA 37 seminar above, doing their thing - with dumb bombs, though. Look out for some very, very low flying. Actual bombing run starts at at around 6:30.

 

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Shame you had a bad experience, I loved driving this one. The owner put in a rear sway bar and new steering rack to help with the torque steer. Very forgiving clutch.

 

I wasn't disappointed in the Viggen, more in myself for beating up the cable linkage in a new car. Still love the color!

 

For it's day, it was quite quick and I really enjoyed the drive. Also, the failure may have had more to do with a factory fault than weakness of design. I wasn't going too easy on it anyway...;)

 

I'm generally a bit gentler these days, but still enjoy banging off 0.25 sec shifts when the moment calls for it. My current car's tremec T6060 is a bit more forgiving of such things. :D

 

-Nick

 

PS - That 2.3L single scroll turbo 4-cylinder has roughly the throttle response of the RM8A/B...but that's not a fault in the fun-to-drive category, generally speaking.


Edited by BlackLion213
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It's been out of Beta for quite a while, I last drove one in 2001....still the only car I ever broke on a test drive. :doh:

 

Lets just say that the shift-linkage wasn't terribly durable or amenable to powershifts....how else do you keep a laggy, single-scroll turbo four on boil for acceleration runs? ;)

 

And mind the torque steer too! That engine has a healthy mid-range that paired poorly with FWD.

 

-Nick

 

The gearbox was always the weak spot for SAAB. It was common to get the standard gearbox replaced with what we called "Police boxes" here in Trollhättan (where the cars were made). SAAB had a division that converted standard cars to emergency services versions and they had more durable gearboxes. They were a bit too noisy to fit the average customer but they worked great. A buddy of mine had a Viggen convertible tuned by Nordic Uhr with almost 400 bhp and a bigger Garret turbo. Worked great with the "Police box". Almost mach speeds. Almost... :D

[sIGPIC][/sIGPIC]

My computer specs below:

 

CPU: Intel Core i5 3570K@4.2GHz | CPU Cooler: Corsair Hydro H100 | GPU: MSI Nvidia GTX 680 2GB Lightning 2GB VRAM @1.3GHz | RAM: 16GB Corsair Vengeance LP DDR3 1600 | SSD 1: Corsair Force 3 120GB (SATA 6) | SSD 2: Samsung 850 EVO 500GB (SATA 6) | Hybrid disc: Seagate Momentus Hybrid 500/4GB (SATA 3) | Keyboard: QPAD MK-85 | Mouse: QPAD 5K LE | TrackIR 5 + Track Clip Pro | Thrustmaster HOTAS Warthog | MFG Crosswind | OS: Win7/64

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I had a slow day at work so i decided to translate the first few pages of the manual for the AJS37. I might do more i find the time. :P

 

AJS37 Drivers Instructions Part 1

 

Edit: Just added a translation of the second tab of the manual.

 

Edit 2: The next section, that covers power supply (hydraulics and electrics), is 39 pages, so that might take a while. :P


Edited by RaXha
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Great work!

 

Thanks! I realize it might be more or less a waste of time since you guys apear ot be close(ish) to finishing the module, and thus there likely exists a translated manual already out there, but i guess i learn more and have more of an excuse to read it this way! ;-)


Edited by RaXha
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