renhanxue

Nice job! I've been thinking I should write something up about the rb 04E and rb 15 since there's really not much information about them publicly available, but I haven't gotten around to it and I dunno if I will anytime soon.

There's been a shortage of good Viggen photos in this thread recently. I present this recent finding as a partial fix:

Oh wait you should have linked like 5 seconds earlier, it turns out Flygmaterielutredningen was a thing. It's classified, of course, and since it's a parliamentary committee I'm not sure how much technical stuff could be in there, but it's certainly worth a try to get declassified.

I don't know anything about that at all, but I bet it could be declassified today. If I could find the documents about it, that is. It's probably somewhere in the archives of Kungl. Flygförvaltningen but I don't really know where to start. Still, I'll keep it in mind - probably a lot of people would be interested in that!

http://www.collectair.co.uk/pdf/interview-hr.pdf

It's not like there even is any definitive answer to the question to the question "why not buy a foreign RWR". You can almost never narrow down any historical event down to having one single well-defined cause. People almost never make completely rational decisions, after all. The real answer is more likely to be of the type "all of the above, to various extents". That I brought up political sensitivity in the first place was not because I thought it was a better reason than what had already been said, just an additional possible reason that might have influenced the decision.

That's not what I said. I said it would have been politically sensitive to buy a RWR (or any American weapons at all) around 1970. Since we didn't do it, it's very hard to say if it could have been done or not (both "would the Americans have been willing to sell" and "would FMV have been willing to buy" are open questions). At no point have I said or even implied anything about the availability of a RWR, FRA's SIGINT flights over the Baltic (with a great deal American equipment, yes), or that Olof Palme was involved personally. I'm still not sure exactly what you think I should admit to being wrong about, nor why you think I don't have enough respect for the air force's lost lives. In fact, I still don't understand what that last part has to do withthe discussion at all.

Like I said in my original post, under-the-table horse trading went on anyway, regardless of what Palme said officially and what the general public believed. I have read those studies you're talking about. Geopolitical support in case of crisis and the exchange of intelligence is not the same thing as trade agreements and purchasing weapon systems - the latter is much more visible to the public and therefore more politically sensitive. I'm really not sure what you're even arguing about at this point.

The ban was because of the engine (formally under export license but hardly top of the line around 1970), and I wonder what might have caused the Americans to do that particular bit of political arm-twisting... might it have been that the Swedish-American diplomatic relations were rather bad at the time? Or maybe it's just that the US wanted to protect its own export interests. I disagree with your claim that it wouldn't have been a political problem to buy an RWR, but it's rather hard to prove a hypothetical argument. I'm just saying, in the years around 1970 it was demonstrably difficult for the Swedish military to purchase American military equipment in general. I really don't understand why you're making this to be a discussion about SUPPORT OUR TROOPS!! or something, nor your accusation of historical revisionism. If it makes you feel any better I can say that I mostly agree with Palme's views of the US in Vietnam, but this is hardly the place to discuss that.

Uh. Did I offend you in some way? Why so aggressive? The man on the street doesn't know what a RWR is. The fact that the Viggen even had one was classified, down to the name of the device ("apparat 27") not having anything to do with what it did. Of course the RWR in and of itself doesn't have any political consequences. What the man on the street might care about is opening Expressen and seeing black headlines about the air force's new aircraft getting equipment straight outta Vietnam. The engine was decided on very early in the project, it was a civilian engine and it was license-built in Sweden and was claimed to be Volvo Flygmotor's in many contexts. The autopilot was developed in cooperation between Saab and Honeywell, it wasn't purchased outright. I dare you to find a single component in the AJ 37 that is actually American - I can't think of one. As for the American missiles, the AIM-9B was purchased in 1960, the Falcon and RBS 67 around the same time (early 60's). After that, the Swedish military did not get to purchase any more American missiles until 1977 - that's when both the Maverick and the AIM-9P were purchased. The entire decade ~1965-1975 was a complete wasteland as far as importing American weapon systems was concerned - it was politically sensitive and relations were bad.

It would also have looked rather bad in the eyes of the general public if Palme's government - the Palme who, in 1972, compared the bombings of Hanoi to Guernica and Treblinka - went off to buy American electronic warfare systems. Of course, under-the-table horse trading went on despite that, but still - anti-American sentiments were very strong in the late 1960's and early 1970's.

I'm done now though, I think I got all the SFI's for the AJ(S) 37 that are actually in the national archives library declassified. so, two weeks?

what do you mean, complex?

Manual says not to launch it above 500m AGL. No idea why, though.

No problems! Figured this might be interesting: Bk 90 engagement envelope. Dashed line is what could actually be reached from a purely kinematic standpoint; solid line is the simplified area shape used by the aircraft's computer for launch permission calculation purposes.

Added part 3 of the AJS 37 flight manual.

Fpl AJS37 speciell förarinstruktion (SFI) del 3.pdf Enjoy!

get hype, etc The still classified chapter is on ECM and RWR, stuff about bk 90 and RBS 15 is in here

I have a release date to announce, because an email came in: I'm not sure exactly what chapter 5 contains but I believe it's most likely weapon systems-related (RBS 15 or possibly bk 90). Look forward to Monday for more flight manuals.

fBE41A9VT3Q check about a minute in when you gaze deep into the afterburner, the afterburner gazes also into you

Yea, they do fly it pretty carefully these days. Speaking of which I'm going to take the opportunity to repost my favorite Viggen air show clip again just because it's so awesome. I mean, here we are: Rovaniemi in Finnish Lapland, of all god-forsaken places. I mean, it's not a tiny city and it does have a fairly big airport, but it's what I'd call a place "långt bortom all ära och redlighet" as Tove Jansson so nicely put it. The runway is literally on the arctic circle. Most display pilots wouldn't ever come within hundreds of kilometers of being this far north, let alone to this little bit of reindeer-infested taiga that's about as remote as you can get in the entire European Union while still having a commercial airport. And of course the weather's absolutely miserable: visibility's bad, cloud base is low and the rain is doing that kind of steady drizzling that just makes you feel like it's late in November regardless of what month it actually is. Even if this had been the Paris Air Show, I'm pretty sure most display pilots just wouldn't have bothered flying on a day like this. And yet, just to spite everything in this world that hates fun, here comes the JA 37, lines up, fires up max zone 3 and goes to town. It's beautiful.

To answer my own question: no, seems unlikely. Can't find figures for 5km, but at 1 km you can only sustain just under 5 G at M 1.1. Graphs for M 0.9 and M 1.1 respectively at 1 km: On the Y axis, thrust (kN), on the X axis load factor. Solid line is total drag, the horizontal lines are available thrust at full military ("MS") and max AB zone 1, 2 and 3 respectively.

It's the line marked "max släckt" in the fuel diagram I posted above, so a bit over 2% internal fuel per minute. Well, it can reach that load factor but the question is if there's enough thrust to sustain it. Here's a a graph of the max attainable load factor for a clean AJ 37: The load factor limitations are the solid lines with numbers on them - read them like height curves on a map. "Higher up" = higher load factor. The colored zones show what the reason for the load factor limit is at that particular altitude and speed. The key on the right should be mostly understandable but to be clear, from top to bottom the reasons are: - 18° alpha - -22° elevon deflection (they won't go further)* - the "pitch gearing", the gearbox that attempts to maintain a constant (well, ish) relationship between stick force and load factor regardless of speed and altitude - limitations on the elevon hydraulic forces (there's not enough force in the system to push the elevons as hard as necessary) For Mach 1.1 in particular or altitude 6km in particular these two graphs may be easier to read: SPAK = the autopilot's artificial stick forces etc active, GSA = no such conveniences. * The elevon situation is actually more complex than this. The elevons can be deflected 27° upwards and 21° downwards, but not all of this is available to respond to pitch inputs. On the AJ 37, 22° up and 16° down is available for pitch input, the rest is reserved for roll inputs. The JA 37 has it considerably better by the way, they redid most of the control surface systems and the same max attainable load factor graph just looks like this: Max permitted load factor (8 G) is easily attainable throughout most of the normal flight regime and even all the way up to 7 km and M 1.8.

100% dry thrust takes you to around M 0.85 at sea level with 2x rb 75, both ECM pods, an empty drop tank and 100% internal fuel. Probably similar for 4x rb 75. Adding two AIM-9's doesn't add a whole lot of drag either.

That is a very nice diagram, RagnarDa! Especially since I haven't seen one like it in the SFI. I can provide one for fuel consumption, though, if you promise not to fall off your chair when you see it, because it ain't pretty: Yes, max zone 3 drinks 15% fuel per minute around M 0.7 and even more than that at higher speeds. At 8 km altitude it's slightly less bonkers, but still.