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renhanxue

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  1. 1000 what? The altimeter's pressure setting is in hPa so 1019 is the setting for mean sea level. 1000 hPa is a perfectly reasonable setting, but 9449 is impossible. Either you're reading one digit too much or you're talking about something other than the pressure setting, I think.
  2. There's almost certainly data from actual flight tests in the national archives, the problem is finding the right place to look. As someone with a decent amount of experience in Swedish military archives, I'd say it could easily take a year to find something like that - weeks of digging through indexes to find likely places to look, then months waiting for declassification and weeks to dig through the results, then repeat because you probably looked in the wrong place the first time but now you know more about how the archive is organized. I've been kinda itching to get back to archive diving, but unfortunately the archives have moved so they're way less convenient for me to get to. I used to be able to spend an hour or two on Wednesday evenings after work there (they were only open evenings one day a week), but now it's like 45 minutes just to get there.
  3. Excellent work, this must've been a ton of effort! Weird to see that the top speed is still this extreme, it's been well established that it's too high for years now. The clean aircraft being extremely fast at sea level is one thing, but doing well over M 1.1 with the draggiest loadouts in the arsenal is just wildly off. Some of the weapons are clearly not modeled correctly, and the 11km test is just nonsensical. I'm almost certain the thrust-to-drag diagram doesn't considers fuel consumption, so in reality the aircraft should probably do slightly better than the diagram as fuel is consumed (the diagram is calculated at 100% fuel for loadouts with the drop tank mounted), but that doesn't come anywhere close to explaining the huge differences here - the benefits of slightly lower alpha are insignificant compared to the enormous transonic drag from the stores.
  4. Other way around; the general rule was no lower than 10 meters over water or 20 meters over ground in peacetime. In mission plans and the like you wouldn't usually see those numbers though, you'd see a call for "lowest altitude", leaving it to the pilots to decide exactly how low was appropriate (with safety regulations like the 10/20 meter floor in mind).
  5. To clarify here, ground collision warnings on the AJS 37 are a complex enough topic to have an entire chapter dedicated to them in the SFI. There are three main cases and then a bunch of special cases mostly related to weapon release altitude restrictions. The first main type is bottenvarning (literally "bottom warning"). This requires the HÖJD CI/SI switch to be in position LD while the radar altimeter is enabled, and the trigger condition is radar altitude < 150m while also being less than half the air pressure altitude (e.g. it'll trigger if the radar altitude becomes less than 50m while the pressure altitude is 100m). The second one is metspövarning, literally "fishing rod warning", and is the one referenced in the OP. As MYSE1234 says it doesn't actually use the radar nor does it require the radar altimeter to be active, but it is nevertheless only enabled if the radar is in mode A1 or A2. The manual explicitly says that the warning does not account for upcoming obstacles, only the current altitude. Presumably the thinking here was that if you're doing the Viggen thing at lowest altitude by the book, this warning would only be a potentially deadly distraction, while it's needed if you have to go head down to use the radar. The third one is really a group of warnings that are enabled while the autopilot's altitude hold mode is engaged. The main case here is triggered if the altitude is less than 80% of what it was when the mode was engaged, but there's a whole bunch of cases here that spans a couple of pages of the SFI and I'm not going to go into all the details. It's notable though that if the radar altimeter is active it continuously updates the reference altitude. There's also special case that doesn't look like the other ground collision warnings (fixed ground collision light on the CI, no blinking lines on the HUD) in case of CK37 failure. None of these cases are capable of warning of upcoming obstacles. If it does that in game then that's a bug. Do note though that in the transonic region (M 0.97 - M 1.05) the computer's idea of the altitude can be rather unreliable even if the radar altimeter is enabled, since in the transonic region the computer replaces the pressure altitude with a calculated altitude base on integration of the vertical acceleration.
  6. First, small terminology nitpick so we can all agree what we're talking about: in Swedish (and maybe also in German), all control surfaces are "roder", but this is not the case in English. A rudder is the control surface you use for yaw - the thing you move with the pedals. The control surfaces we're talking about here are called elevons (combined elevators and ailerons). I think the misunderstanding was already cleared up in this thread, but just to make sure we're all on the same page Yes, 22° is the max deflection that can be achieved with a pure pitch up/down movement of the stick, but the missing bit here is that this is both altitude and airspeed dependent. As dynamic pressure increases (that is, you fly faster and/or lower), you get more force per degree of control surface deflection. If the control system didn't compensate for this, the aircraft would be essentially unflyable at high speeds because the stick would be extremely sensitive, and any big movement would rip your wings off. So, the Viggen has two almost literal hydraulic gearboxes (one for pitch and one for roll) that attempt to keep stick force per G the same regardless of airspeed and altitude. The roll gearbox only has two modes, high speed and low speed, and switches between them at 350 km/h IAS. The pitch gearbox though is continuously variable, and at its highest setting (least control surface deflection for a given stick movement), the max pitch-up deflection is only 8.7°. Here's a chart of max elevon deflection by airspeed and altitude, in SPAK mode (from Fpl 37 aerodynamik III): The line at M 0.93 corresponds to the "series trim" kicking in to correct for transonic and supersonic effects, and since control surface effectiveness is reduced at transonic and supersonic speeds, this also coincides with an expansion of the deflection envelope by about 3.5°. We're not done yet though, because there's yet another thing that can mess with the elevon deflection, and that's the "droop mechanism". This is used to add a drooping offset (additional pitch down deflection) to the elevons, and it's controlled by the canard flap control mechanism. This is connected via a mechanical wire linkage to the droop controls, so when the canard flaps are deploying the elevons are continuously drooped at the same time. Unfortunately I don't know how big this deflection is, since the SFI doesn't say, but this is probably at least part of the reason why you're seeing a surprisingly small deflection upwards when in landing configuration - you effectively have some invisible pitch down trim already, to compensate for the pitch up trim change caused by the canard flaps.
  7. The AJ 37 is a strike aircraft with only very limited A2A capability. The fighter variant is the JA 37, and that one does have a cannon and integrated countermeasures dispensers.
  8. The Viggen has absolutely no problems with slowing down fast if it needs to, just turn and you'll get rid of speed in a hurry. Also the thrust reverser really messes up the yaw stability, it'd be very dangerous to use in the air and there are multiple safety interlocks that prevent it from happening.
  9. You basically shouldn't. In the real aircraft there's even a thin lock wire keeping it in the AUT position, which should tell you what level of "don't mess with this" it's on. The specific (and rare) fault condition the switch is supposed to be used for has to do with the automatic engine restart system. There's a flameout detector in the combustion chamber, and if that trips, the engine ignition system is turned on in order to try to restart the engine. This is accompanied by a master warning and the lamp TÄNDSYST on the annunciatior panel (it remains lit as long as the ignition system is on, even if you acknowledge the warning). If the flameout sensor is faulty and constantly sending a flameout signal, then the ignition system is on all the time, which is obviously undesirable. You can disable the flameout sensor (and the automatic re-ignition) by flipping the TÄNDSYSTEM switch to MAN. If you then try to manually restart the engine with the ÅTERSTART switch, the TÄNDSYSTEM switch automatically flips back to AUT. I have no idea if a faulty flameout detector is a thing that DCS can simulate, but there you go, that's what it's for.
  10. razo+r is correct, but to put it in a different way: Sidewinders and the ECM/chaff&flare pods can always be added to any loadout (assuming you have suitable stations free). The gun pods can be used together with rb 05 or rb 75. Other than that, you're limited to a single weapon system at a time. Asymmetrical loadouts are supported though. Compared to a modern multirole fighter this might seem weird but it makes sense in the operational context the aircraft was designed for. It was exclusively made for "one pass, haul ass" missions against pre-planned targets. CAS was not a thing the Swedish air force even considered doing at the time. Mixing weapon systems would have added a lot of complexity to the already extremely complex (for its time) onboard computer, for almost no benefit. The fact that you can't carry countermeasures together with some of the most important weapon systems though is definitely a design flaw and was controversial even at the time; my impression is that the capability was dropped for cost reasons (it was added on the fighter variant JA37 later though). It's important to note though that the normal way the AJ 37 was operated was in groups of at least four aircraft, or more rarely in pairs - almost never alone. If you for some reason really needed multiple capabilities in one mission you just assigned them to different aircraft in the group. Even then though, A2A weapons would not normally be carried for strike missions - the aircraft is completely reliant on its speed at low altitude for survival, and if it gets into a dogfight something has gone extremely wrong. The reason they can be carried is so it can be used to intercept bombers and paratrooper transports in a pinch. The all-aspect Sidewinders were a very late addition in the aircraft's service life. e: To address the actual problem: post your keybindings for TV/T1/T0, that switch has confused people in the past
  11. I responded to the PM all the way back in November but never posted here for some reason, so just to put this out there: if anyone else wants to do this for any language, by all means go ahead! I'm very happy that the writeup is interesting to others. Also, feel free to link to your translations in this thread so people who encounter the English version first can find translations from here too.
  12. Cheeky of you to replace the emergency checklist with the FL/metric conversion chart as seen in Gustav 52... Also, if the screenshots may be believed, the waypoint button labeling (W1-9) doesn't match the destination indicator labeling (B1 in the screenshot).
  13. Crossposting for visibility - @Amarok_73 reports that the LT-KRAN EBK (afterburner low pressure fuel cocks) switch appears non-functional:
  14. Ah okay, it's just a confusion of terminology then, I'd call that switch "afterburner low pressure fuel cocks" (Chuck's guide calling it "manual afterburner fuel regulator" is also confusing, because there is another switch that is actually called that which does something different). I... don't think you're supposed to use that except if the aircraft is on fire, honestly - that entire panel is all switches that are for emergency use only. Still though, if it was modeled and now it isn't then that sounds like a bug to me. I'm not at my gaming PC either though so I can't try to reproduce. I cross-posted to the feedback thread - Machalot has been doing a heroic job of bug reproduction there, maybe they can help.
  15. There isn't, unless he means the detent on the throttle, but then the post makes no sense. I honestly have no idea what you're trying to do or which switch you're interacting with, @Amarok_73. I'd appreciate if you could elaborate.
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