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That's the JA 37, the air superiority version - we're getting the strike version. Almost (but not quite) the same airframe, but almost everything else is different. The strike version only has Sidewinders and gun pods for A2A. As far as the SR-71 intercepts go though, this is obviously the place to repeat the story on how to successfully intercept it with an aircraft that has a top speed of 1450 km/h IAS (M 2.0 at altitude), a service ceiling about 25000ft/8000m lower than the Blackbird's and a max radar lock range that's about same as the distance the Blackbird travels in a minute. The first part of the text is mostly a direct translation of a chapter from the book "System 37 Viggen" (Edlund & Kampf, ed. Flyghistorisk revy, 2009): The second intercept occurred a week later, on November 1st, 1982, with another pair of Viggens from the 13th air wing: Another intercept worth mentioning involved a group of three Viggens and occurred on January 9th, 1986. The group started southward from Norrköping with the intention of intercept training, but immediately after takeoff it was ordered to prepare to intercept a target that was suspected to be a SR-71. The group climbed to 8000 meters on a southeasterly course and then turned northward over the Baltic sea southeast of Västervik, forming up in a column. At this point the JA 37 had been equipped with the fighter-to-fighter data link, so the Viggens could share targeting data with each other, not just with the ground. All three aircraft conducted a simulated missile firing independently. The intercept started at 13:14 local time and was complete at 13:25; the intercept point was about 50 km west of Visby, on the island of Gotland. The target was flying at an altitude of 21,500 meters at mach 2.9 and as usual attempted to jam the PS-46 radar. The Viggen group had had plenty of time to climb and accelerate, so when the lead and the second aircraft had passed the target the flight lead gave the call to just continue the flight at maximum speed since the mach number at that point was around 2.0. The third aircraft did not reply, though, so the leader asked for his status. The answer was "I'm gliding". The third aircraft had suffered a high temperature compressor stall. The engine had surged briefly, the exhaust temperature rose and the warning light "EXHAUST TEMP." was lit. The pilot followed procedure and turned the engine off, and then restarted it when he descended below 12,000 meters. A flameout at that kind of altitude was very scary since without bleed air from the engine, the cabin would lose pressurization within minutes. The entire group exceeded 18,000 meters of altitude during the intercept. The Swedish air force recorded over 50 successful SR-71 intercepts between 1982 and 1988. The intercept geometry is actually pretty bananas when you think about it, and so are the timing windows available for the intercept. For the SR-71, the entire trip around the Baltic sea only took half an hour. It was a pretty convenient "cheat" for the Swedish air force that they could see the SR-71 coming on the outbound leg and have plenty of time to scramble fighters and get them to the correct position to intercept it on the return leg, since they knew where it was going. The SR-71 was actually pretty limited in where it could go - the Baltic sea really isn't very big compared to the SR-71 turn radius at mach 3 and that's why it had to slow down when turning around at the northernmost part of the trip. At the point where the SR-71 starts its 180 degree turn at the northernmost part of its trip, there's maybe six or seven minutes left to the preferred Swedish intercept point. When it's halfway through the turn, around three minutes remain to the intercept and at this point the intercepting fighter has most likely already started its acceleration and supersonic climb. A thing to note here is that at this point, unlike when it gets launched at with SAM's, the SR-71 can't tell that it's going to get intercepted. Its electronic warfare suite and radar warning systems are only picking up the rather harmless sweeps of the Swedish ground based PS-65 or PS-66 S-band long range search and surveillance radars, nothing from the JA 37's vastly more threatening X-band fighter radar. It doesn't have a radar of its own and can't see the Viggen. This leads into the next interesting part: because of the ground-to-air data link, the JA 37 doesn't even need to be radiating while it's climbing to intercept. With the PS-46 slaved to the data link, as soon as the JA 37 gets into radar lock range it will instantly have the antenna pointed directly at the target and it can go directly from silence to single-target-track mode. By the time the JA 37 locks on, there's maybe 45 seconds or so to the closest point of approach between the two, and even if the SR-71 starts jamming it's unlikely to break the already established lock. I think these tiny time windows were the bane of most other SR-71 intercept attempts. Getting into position without the data link, sure, that's doable, it's just a plain old ground controlled intercept - Drakens managed to do this occasionally. However, when you only have less than a minute to find the target on your own radar, lock on it, prepare and fire a missile while at the same time flying the aircraft at the very edge of its maneuver envelope you really don't have much or even any time to **** around with trying to penetrate ECM or fiddle with radar settings head down. Maybe a Tomcat could do it with the RSO handling stuff from the back seat, I dunno, but in a single seat fighter with 1970's ideas of "user-friendly" interfaces, it's gonna be really damn hard. That's why the JA 37 succeeded: the pilot workload was manageable.

No. Closest thing you get is the rb 04E anti-ship missile which has a home-on-jam fallback mode in its seeker.

The staff can use whatever equipment they want, it's just visitors that are limited to handheld cameras. And it's true, since it's a ring binder with loose pages you could just stuff them into a regular multifunction printer and have it scan for you - I was thinking of regular bound books. You can probably email them in English by the way, I think they'll think that is easier than machine translated Swedish. Allowed by who, the guy who photographed them? If you have them photographed they've definitely been declassified or someone's made a huge ****up somewhere (and you can't get in trouble for that, since you're not qualified to judge if it's sensitive or not).

Not much, but see the discussion here and on the following page.

In the library at the national military archives, most likely, but as far as I know it has never been declassified. I dunno if they will initiate the declassification process for a foreign national or if they're willing to scan it for you (may cost quite a bit of money, you're probably gonna have to pay for the labor of the poor guy who's flipping all those hundreds of pages on the scanner) but it doesn't cost you anything to ask.

FK = Funktionskontroll, self-test basically. When it says things like "fällströmställare" and "tryckströmställare", it doesn't have anything to do with what the switch does, just what kind of switch it is (tryckströmställare = button, and in this case fällströmställare seems to be a 3-way switch). "Strömställare" can be translated to just "switch". The MOTVERK light just means any of the countermeasures are active IIRC. It's in the manual somewhere. ÖVRIG ELNIK RADAR MOTMEDEL is a switch for choosing whether to test other electronics, radar, or countermeasures - ELNIK is just a cute way to abbreviate "elektronik". BTW check the "ändring 90" PDF, it has some more details I think.

Right, that's what I get for speaking from memory instead of just checking the manual.

Various stuff that I can't be bothered to PDF-ify. Most of it is kinda incomplete by the way (pages or sometimes entire chapters missing).

Returning to the data cartridge, I put up a bunch of fairly obscure stuff I can't be bothered to PDF-ify on my Google Drive if you want to go even deeper into the rabbit hole. There's a little bit more on the cartridge in the "Fpl AJS37 beskrivning del 4" folder, IMG_0862.jpg and onwards. By the way did you know a JA 37B capable of carrying rb 15 and rb 75 was proposed as early as 1979? I guess that explains why that designation was never used and we went straight to C-mod (edit 32) and then JA 37D.

Looked at the video again and it seems like you're referring to the striped hand on the fuel meter (popularly called slipsen or "the necktie" in Swedish - it's even referred to by that name in the flight manual). That's not the actual fuel fill level. The fuel fill level is indicated by the white hand that shows 100% in that scene (but later, after taxiing out, that hand has indeed moved up to 125%, indicating Cobra was being sneaky with his drop tank). The necktie, on the other hand, shows your fuel reserve - if you fly the programmed waypoint route at the programmed speed, you will have the fuel amount shown by the necktie left when you land (or when you arrive in the landing pattern, don't remember which). That's why it jumped up when the data was loaded from the cartridge - a waypoint route for it to estimate fuel consumption from was loaded. It's a very handy bingo indicator. IIRC if you don't program a landing base the computer will assume you want to return to the base you started from.

It's battery powered at least but I don't remember off the top of my head how it works. I think I have some more details about it somewhere but I'm not at home at the moment, will try to look it up tonight. e: page 16 in this PDF: IIRC it has like 8MB of memory or something huge like that (well, huge for early 90's)

The fuel indicator goes from 100 to 125-ish percent if you hang a full drop tank, so that might be what happened.

It may or may not have been a mistake in the declassification process but there's really no hard data to speak of in that section of the manual - no range, no warhead weight, no details about the seeker, nothing. There are some quite vague descriptions of the targeting logic but really, remember that this is a 30 year old missile design we're talking about here - rb 15F became operational on the AJ 37 in 1989. I also strongly suspect that the missiles themselves are about to pass their "best before" date if they haven't already. The Gripen is capable of carrying them but I really do wonder if there are actually any missiles to launch. A 20 year shelf life was the norm in the 90's (bk 90 was designed for that according to the information from the cluster munitions treaty dug up by microvax, for example) and we're well past that even if we're being generous and assuming they ordered new missiles for the Gripen A - I suspect though that any rb 15F's still in the inventory are the originals from 1989. Wiseman also mentioned that the 2014-2020 equipment plan said that the missiles would have to be replaced (or refurbished, I guess) in the later half of the 2010's. It may further be noted in support of this theory that while the Air Force claims to have the rb 75 (Maverick) operative on the Gripen in reality they do not actually have any such missiles. The Gripen can carry later Maverick variants but not the A version that they actually had and there has never been a purchase or an upgrade to newer versions of the missile. Again, see Wiseman's post above and also J. K. Nilsson's similar post with a few more details.

The Viggen's autothrottle feature is called automatisk fartkontroll (AFK). If you like me are twelve years old mentally, well...

Is "vinkelhopp" not implemented or am I misunderstanding what "first and second" etc means?

It's not unstable in the transonic region, but there are trim changes and that's what the light is calling your attention to. The SFI (del 2 kap II) says: The issues start if the autopilot has failed somehow so you don't have the oscillation dampening and trim help etc that SPAK mode provides. In the fallback mode (GSA) the aircraft starts having weak pitch down tendencies at M ≈ 0.85, changing to pitch up at M ≈ 0.95, and then changing back to pitch down at M > 1.03 and increasing in force as M increases. Additionally: e: the aerodynamics compendium has more to say about this though, namely that certain types of underwing loads (ARAK and countermeasure pods mentioned) make the available pitch authority quite low in transonic and supersonic regimes.

IIRC there's a button called "IR-RB FRAMSTEGN" that is supposed to cycle through the heaters. Don't know what it does if you have both types though.

the relevant pages from speciell klargöringsinstruktion

The rb04's all choosing the same target is realistic, that's what happened when FOA simulated it back in the 60's/70's too, and that's why they added the group targeting mode.

At this point "they did it just to be weird" honestly sounds kinda like a plausible explanation. I have one alternate theory, though: on the Draken they had some issues with getting enough luminance out of the display when the cockpit was lit up by the sun, so there was a hood that shaded the radar screen. Maybe they figured that it'd be easier to get a bit more contrast out of it this way. I really don't know, though. As far as I know nothing else works this way - only the AJ 37.

I don't know why exactly they chose to do it this way, but yes that's how it works. All other Swedish radar installations I know of including the ones on the Lansen and the Draken work in the expected fashion (bright echoes, dark background), so the AJ 37's display was deliberately inverted for some reason.

It is your job to avoid terrain, the radar will just tell you about it. Darker areas are radar returns (=mountains), lighter areas are clear.

afqWWnSjTtA Another treasure from the final days of Martin Blå.

The flight path marker is exactly that. There is no numerical airspeed indication in the HUD, but the "tailfin" on the flight path marker can detach from the circle that represents the aircraft body to tell you if you're going too fast or too slow. If the tailfin hovers above the marker, you're going faster than your current planned speed (appropriate glide slope speed during landing, or planned speed entered in the nav computer for your current leg during normal flight); if it descends into the circle you're going too slow, and if it starts blinking while doing that, that's a stall warning: you're at a critically low speed and must increase throttle/lower nose immediately to avoid the stall. During takeoff the flight path marker behaves slightly differently (it's effectively an attitude marker only) but I won't go into that right now, read the SFI if you want the gory details (SFI AJS37 del 1 kap 1 flik 17 punkt 4.3). "3,0" on the horizontal line is your current altitude, 3.0km (the Swedish decimal separator is traditionally a comma). Below 995 meters the display changes to meters shown with three digits (000-990). Above 9.9 km the display wraps around and you need to add 10km to it yourself, so a displayed number of 1,2 can mean either 1200 meters or 11200 meters. Trivia: while in aiming mode, the numerical altitude moves to the right side of the HUD while the trigger is depressed. 35 and 36 are indeed heading in degrees divided by 10, and the small vertical line to bottom right is a 5-degree marker, like you suspected. +5/-5 is attitude above/below horizon, as you say. The vertical bars are the best part of the Viggen HUD. I haven't seen anything like them in any other HUD I can recall. They are a quick way to tell you if your flight path is currently on the planned altitude. Imagine that the bars form a colonnade stretching off into the distance ahead of you. You want to fly along the tops of the columns, so to do this you align the tops of the bars with the artificial horizon. If you do that, you're at the planned altitude (as per the nav path). If the tops of the bars are above the horizon, you're too low (you're flying below the tops of the bars and looking "up" into the colonnade) and vice versa. If you're below 500 meters, there's also an extra bar to each side with the length 100 meters, so you can gain a visual estimate of how tall the bars are. In the screenshot the aircraft is way above the planned altitude. Not present in the screenshot is the second best part; the timeline. The timeline is a horizontal bar with three "notches" on it that starts out pretty long and shrinks from both ends towards its center to indicate time or distance left to objective (nav waypoint, bomb release point, that kind of thing). It can even tell you if you're in engagement range for your heaters or not. e: I don't have enough experience with flight path markers to know if the Viggens' is weird or not, but here's the explanation of what its position means:

Dodging and weaving is a bit of an exaggeration. When it gets within a few kilometers of the target (from memory, someone with the manual handy correct me) it changes course to one that is something like 15 degrees offset from the target and the turns in towards it in the terminal phase.