Backy 51 Posted December 23, 2016 Posted December 23, 2016 Quite an accomplishment. "By the mid-1980s, Swedish Viggen fighter pilots, using the predictable patterns of Lockheed SR-71 Blackbird routine flights over the Baltic Sea, had managed to achieve missile lock-on with radar on the SR-71 on numerous occasions. Despite heavy jamming from the SR-71, target illumination was maintained by feeding target location from ground-based radars to the fire-control computer in the Viggen. The most common site for the lock-on to occur was the thin stretch of international airspace between Öland and Gotland that the SR-71 used on the return flight.[83][84][85] The Viggen is the only aircraft to get an acknowledged radar lock on the SR-71." Source: Wikipedia post. Of cource, we now need the DCS Blackbird to recreate these historic encounters! :D I don't need no stinkin' GPS! (except for PGMs :D) [sIGPIC][/sIGPIC]
RaXha Posted December 23, 2016 Posted December 23, 2016 Yes, it's important to make the point that that feat was done by the JA 37 interceptor variant, and would not be possible to achieve in the AJS 37 in any way. :P
renhanxue Posted December 23, 2016 Posted December 23, 2016 (edited) 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 JA 37 tactics development unit got started quite early on with working on a mission profile for intercepting targets at very high altitudes. The targets considered were the SR-71 Blackbird and the MiG-25 Foxbat; both types were capable of mach 3 at altitudes above 20,000 meters (65,000 ft). Since the Viggen obviously wasn't fast enough to catch up to the target, the profile they came up with involved the intercepting aircraft meeting the target on a directly opposite course, with intercept vectors and combat control provided by ground-based installations over datalink and/or regular speech radio (in Swedish terminology, the air combat control system was known as "Stril", portmanteu for "Stridsledning och luftbevakning", which means something like "combat control and aerial surveillance"). This meant the JA 37's PS-46/A radar would be supported by the ground-based Stril ones - the intercepting aircraft obviously couldn't catch the target on its own radar in time to climb and accelerate to intercept. The tactics and armament systems were developed in the JA 37 systems simulator at Saab, with the simulator connected to Stril. For obvious reasons there were no opportunities to practice against our own aircraft in reality. The mission profile started with acceleration in level flight to mach 1.35 at 8000 meters (~26,000 ft). Then the nose was raised to 3-5 degrees above the horizon in order to climb while accelerating further. The USAF SR-71 recon missions were commonly known as the "Baltic Express". Usually, the SR-71's entered the Baltic at an altitude of about 21,500 meters (70,000 ft) about 80 km south of Copenhagen, accelerated to mach 2.98-3.0, continued eastwards and then northwards along the coasts of East Germany, Poland and the Baltic states, followed by a left turn westward, crossing the Baltic sea to the Swedish side just south of Åland, then another left turn southward and flying through the narrow corridor of international airspace between Öland and Gotland. Initially the left turn westward south of Åland was so wide that the SR-71's ended up violating Swedish air space, which led to a diplomatic protest which caused the SR-71's to slow down to mach 2.54 during the turn before accelerating to mach 3 again on the southbound leg. Between 1977 and 1988, 322 such missions were flown; in a few cases the mission was also flown in reverse. Map of a typical SR-71 flight (note the times - wallclock time - noted along the flight path, the violation of Swedish airspace near the top and the Soviets running circles in the top right): The big island above and to the right of the center of the map is Gotland; the smaller, narrow island near the Swedish mainland is Öland. Åland is beyond the northern edge of the map. The intercepts would typically be done either around the place that says "0910" on the route, or just after the SR-71's left turn was complete. Simulator training on the mission profile started in Norrköping at the 13th air wing (one of the first wings to receive JA 37's; it had been equipped with them during 1981) for both pilots and air combat controllers. You couldn't know who ended up getting the intercept, so everyone was trained. The first real intercept opportunity came on October 26th 1982, when a pair of Viggens encountered an SR-71 for the first time. One of the pilots tells the story: We had no extra time for getting into position before the intercept, so there was no margin of error. I got a radar lock on the SR-71 during its left turn north of Gotland and I remember being somewhat surprised by the unusually long target velocity vector on my radar screen. The target altitude was above 20,000 meters, speed exceeding mach 2. Because of the great closing speed, the supersonic climb had to be started at a great distance, greater than you'd think if you hadn't practiced beforehand. The final stage of the intercept went very quickly and it turned out to be a perfect 180 degree interception. The climb attitude increased gradually in an arc upwards in order to keep the target within the engagement envelope presented on the radar screen. The target started jamming our radar, but it kept the lock. I started getting antsy regarding the flight profile after the simulated missile firing, since my nose was pointing very far up and I was slowing down. But aborting now didn't feel like an option now that we had finally gotten the opportunity to try our capabilities against this very difficult target. When I had "fired" my Skyflash (rb 71 in Swedish service; a British improvement of the AIM-7 Sparrow semi-active radar-guided missile) I looked up and saw a black shadow pass over me and continue to my rear. Just a shadow, I couldn't make out any details. Normally when you fire a Skyflash you're supposed to maneuver so that you maintain your radar lock on the target until the missile hits. I seem to remember that in this case though I didn't have much room for manoeuvring. I had to concentrate on sloooowly rolling the aircraft around and get my nose back towards the horizon so I could accelerate again. I think that when we evaluated the mission recording and the simulated missile firing on the ground afterwards, we thought that the intercept could possibly be regarded as successful. But the margins of error when intercepting an SR-71 with a JA 37 were very small. You needed a carefully considered starting position, very precise directions from the ground, very precise flying and, certainly not the least important, that the target didn't change its course at all during the intercept. The second intercept occurred a week later, on November 1st, 1982, with another pair of Viggens from the 13th air wing: I was over the sea near Gotland when I got the order to prepare for an intercept. I got the target info transferred to my aircraft over data link and presented on my radar screen and tactical display. I accelerated to mach 1.35 at about 8,000 meters (~26,000 ft) and started pointing my nose up; I had full afterburner on during the entire intercept. I chose the Skyflash on the weapons panel for a simulated firing. The JA 37's max radar lock range was about 60 km and the tactical display showed up to 80 km of my surroundings in one direction. I slaved my radar to the Stril data link. The target info from Stril showed that the target was flying in a westward at mach 2.54 at an altitude of 21,500 meters (70,000 ft) in the far distance. The air combat controller on the ground gave me an intercept position south of Åland and I quickly assumed that the target could be either a MiG-25 or a SR-71. The target turned left and towards me. The closing speed increased very quickly as the meeting angle approached 180 degrees. The circle on my radar screen that indicated target data provided by the Stril ground installations popped up, indicating an echo at maximum range. I gave the lock command and the PS-46 locked on immediately. The target initiated intense radar jamming, but I didn't lose the lock. The engagement envelope for the Skyflash was presented on the HUD, the radar screen and the tactical display. I conducted a simulated firing in the middle of the envelope with an aiming error close to zero. The closing speed was approaching mach 4.5 and the target indication was starting to point upward. I was quickly approaching my permitted ceiling of 16,000 meters (52500 ft) and I was still supersonic. I briefly got a visual on the target (a SR-71) which appeared charcoal grey as it passed 2-3000 meters above me. I started rolling over, very carefully, in order to bring my nose down. My maximum altitude turned out to be about 18,500 meters (60,700 ft) and my slowest speed during the intercept about mach 1.35-1.45. When I re-entered the normal flight envelope at 16,000 meters I gradually eased off the afterburner. When I came back to base a phone call was waiting for me, with a colonel at the Air Force HQ in the other end. He was well aware of my intercept and I had a brief chat with him, where he asked me if the mission had been successful and if the aircraft's weaponry had worked as planned and so on. The general impression was that everything had gone according to the plan. The recording of the mission was analyzed and shown to all pilots at my squadron, as well as to the tactical development unit. We simulated the missile firing on the ground and it was judged a success. 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. Edited December 23, 2016 by renhanxue 1
AdurianJ Posted December 24, 2016 Posted December 24, 2016 An SH-37 Viggen got a maneuver kill on an Su15 over the baltic in 1985. The SH-37 was very similar to the AJ-37 Viggen it had switched some weapons options avionics for recon equipment. In 1981 Formations of AJ-37 Viggen took off loaded with RB04E's to strike a soviet flotilla believed to have penetrated the Swedish border while J35F Draken flew CAP. In 1994 a Viggen accidentally landed on a road near the airbase did a reverse thrust 180 and took off again blasting the front end of a civilian car with gravel in the process !
RaXha Posted December 24, 2016 Posted December 24, 2016 (edited) In 1994 a Viggen accidentally landed on a road near the airbase did a reverse thrust 180 and took off again blasting the front end of a civilian car with gravel in the process ! Imagine going along in your volkswagen and suddenly having a Viggen comming at you at full speed on the street! :lol: Full story: Wednesday, November 16, 1994 would root Petter Petter 29 and 19, JA 37 or F 16, land on Byholma airbase. Number one landed without problems on the main strip, but number two, 19 37419 Petter, happened to land on runway B (short runway hon main road 545) instead of the main strip. In a commemorative publication on Byholmabasen one can read an excerpt from the radio traffic (here slightly paraphrased): FF: Reports that he is on route. MIF: Reports wind direction and that landing strip is clear. FF: ”Comming in for landing” FF: ”What intersection was this?” (korsningen Lidhult-Odensjö) FF: ”Is it straight ahead here?” MIF: Reports that he has no visual contact with Petter 19. FF: ”Is it possible that i have landed in the wrong place?” MIF: Once again reports that he has no visual contact with Petter 19. MIF: ”Petter 19, are you one the ground or in the air?” FF Doesn't respond since he is occupied reversing around an intersection. FF: ”I'm comming” Petter 19 eventually landed on the main strip and after taxing the wrong direction for a while arrived at H2. MIF = is the military ATC during the exercise. The fact that the pilot happened to land on a road that hadn't been closed of was serious enough, but what was even more serious was that he pulled around and took off again! During this maneuver Anette Rydén came driving in her car at the intersection Lidhult-Odensjö, but felt compelled to back away. Newspaper Smålänningen learns she had said "Now i might need to get a flight radar in the car!" And "Should they continue in this way, they may well make license plates." The day after they found that a number of road signs were blown down and the chimney in a neighboring house had burst because of the vibrations created when taking of with AB Zone 3 (max AB). This is what Anette had to say about the incidents a few years later: She had come to the short strip from the Odensjö direction, and stood and waited to turn out onto the road when the airplane came rolling. She was really scared and thought it was the Russians who came, fighter aircraft with a pilot who had a helmet and with hoses and stuff. After a little while she saw the swedish markings on the aircraft, and then she calmed down a little. Meanwhile, a car connected from Odensjö, I do not remember exactly his profession, it was probably the plumber, but it was a person who knew Anette. He had run up and instructed her to back away a bit, they moved their cars and the Viggen started reversing toward them. "The wheel turned to the side and backed up against us." When he backed into two trucks drove past, then taxied the aircraft out "and turned up the volume" and vanished away. It should be added that the road he landed on was actually a short strip to be used during war, but it had not been closed of for this particular exercise. :P http://imgur.com/a/qYZ4h Edited December 24, 2016 by RaXha
antagonist Posted December 24, 2016 Posted December 24, 2016 Imagine going along in your volkswagen and suddenly having a Viggen comming at you at full speed on the street! :lol: Full story: This is what Anette had to say about the incidents a few years later: It should be added that the road he landed on was actually a short strip to be used during war, but it had not been closed of for this particular exercise. :P http://imgur.com/a/qYZ4h MY SIDES!
AdurianJ Posted December 27, 2016 Posted December 27, 2016 I read about how the Viggen squadrons would act in case of an attack. A plan evolved where all the aircraft would be fueled and would take off even without armament in case of hostilities. The planes would fly along the Norwegian border at the most fuel economic speed they could which was out of range of Russian fighters. During the 2-3 hours the planes where safe in the sky the ground-crews would get weapons ready so the planes could land arm up and fly off to engage the enemy. This whole tactic was tested during an exercise where it succeed spectacularly.
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