esb77

The proliferation of these Su-27 pitch trim/nose down inversion threads finally inspired me to try a flight with the FSC turned off. Starting with the taxi. It took four tries to get a good takeoff and landing. It feels sort of like skating on still wet Zambonied ice with skates that are a bit dull. ANY input you give the plane will cause it to react with every bit of maneuverability you asked for. This includes things like operating gear, flaps, and the airbrake. There are basically two rules the pilot needs to follow at all times. 1. Unless you wish to die, NEVER move the stick forward rapidly. 2. Do not over-control the plane. Follow them, and refrain from giving the plane any new aerodynamic inputs, and it's not hard to reach equilibrium. Give it the slightest change in input though, and you find that the equilibrium is not at all stable. It's also a very high pilot workload. I'm semi-tempted to do it some more though. As difficult as it is, it's also sort of like the plane is directly controlled as part of your body. It's no easier than learning how to walk or how to ice skate (there's a high probability of falling down a lot), but you get a feel for how the plane is flying and what its true capabilities are in a way that almost completely disappears when you turn the FCS back on. Long story short, with the FCS on at least 3 pilots worth of workload is magically caused to vanish. The trim is mild, predictable, and allows you to get away with handling the stick like a staggering drunkard. The weirdest thing was that with the FCS off I had to move the stick back surprisingly far to rotate on takeoff. It was very reluctant to get off the ground below 370 km/h. It makes life interesting, because it's easy to pitch up too much and stall (and crash and die), but once you come off the ground with a lot of back stick, you can't move it forward rapidly to recover (because you invert, stall, crash and die). Su-27_FCS_off.trk

That really depends on your input hardware. Flying with a TM-Warthog with an extension, and leaving it linear is probably the way to go. Cheap old stick that's sticky, or has a bit of play, or with fading pots, and there's a good chance that 10-30% of curvature on the pitch and roll axes will be helpful. Experiment with different settings and see what works for your setup.

There is auto pitch trim in the Su-27 flight model. However, it is not designed to create or maintain level flight without pilot input. It is designed to make the Su-27 behave like the vast majority of aircraft that pitch up with speed increases and pitch down with speed decreases. In a high performance aircraft with a wide speed range that behavior can produce a lot of pitch under the right (or wrong depending on how you think of it) conditions. The early models of the Mig-29 and Su-27 were known for imposing a higher pilot workload than the contemporary NATO counterparts. You have to pay attention to the fundamentals of good piloting from when you start rolling to when you stop rolling. They're also very responsive planes, sometimes more than Western counterparts, so it's easy to get in very deep trouble very quickly if you have a brief lapse in attention. If you find that stressful, well, that's what vodka is for when you come off duty. Parts of it may be that the FM is still WIP, but these planes are more demanding than some. Think of it as an opportunity to improve your airmanship. After all, if the plane could fly itself what use would the pilot be? I don't know what the thinking was at Sukhoi when they were designing this, but one feature was commonality in the pilot interface across different planes. Mig-29s, Su-27s, Su-25s, and probably others have very similar cockpit designs as a deliberate feature to facilitate rotating pilots into different aircraft. It's possible that they decided to carry this philosophy over into handling characteristics as well.

The Su-27 SEAD procedure is as follows: 1. Let someone else do it. 2. If step one fails try to figure out how capable and dense the AD coverage is. 3a. If there is any chance that the AD is highly capable or has overlapping coverage, stay well outside its engagement zone. 3b. If you're sure that it presents a low threat level you can operate at the edges of its engagement zone or . . . 4. Sneak in and take it out with your 30 mm. Basically against any halfway decent air defense the Flanker should just stay away from it.

Infra Red Scanning & Tracking system.

Well they weren't being very clear. There's the tendency to invert in the first place, which is about CoG and aerodynamics and likely not all that different across the Su-27 family of aircraft. Then there's the tendency to stay inverted through a distressingly large chunk of altitude while recovering. That may be significantly different with thrust vectoring. In general though I think it's less a matter of the Su-27 loving to go nose down than of DCS customers loving to do things that the aircraft manual says should never be done due to the risk of unrecoverable loss of pilot control. Probably because we all watch too many airshow videos but don't bother to remember that those are the very best available pilots, doing many things that pilots in most units are absolutely not allowed to do under any circumstances.

The other option is to get a bit more sophisticated in how you manage wingmen, though in some missions it doesn't work all that well. If you're confident that you can take out all of the dangerous air defenses: Radar SAMs, IR SAMs, Gepard, Tunguska, and Shilka AAA, then you could try ordering your wingman to orbit in a safe area while you do SEAD/DEAD and then order it to join up again and hit ground targets after the threat level has been reduced. For the Su-25T that combined with the Target My Target command can make the wingman pretty useful. In the Su-25 campaign, I'd agree with the mission editor being the best bet. Between the aircraft capabilities and the mission design you often don't have the loiter time or precision strike capability to significantly reduce air defense threats and still have the fuel to complete the primary mission objectives. If you're playing around with the mission editor, one thing you can do is edit the speed that your wingman flies the mission. In this case if you get there and have enough time to unload and egress, then you can use the "jump to other plane" command and take direct control of the wingman before it gets to the target area. Once you've swapped planes use the radio menu to tell your initial plane to RTB and use the wingman's plane to make a second attack run. If you're acting as flight lead, part of your responsibility is to evaluate the mission plan and eliminate the crazy/stupid/suicidal elements as much as possible. That means considering the limitations of you pilots and your equipment. In that sense, altering the mission profile and loadouts of friendly planes is more a matter of being a competent flight lead than of "cheating" on the mission. Also a good idea to practice on increasingly difficult mission tasks for you and a wingman. Starting on a difficult campaign mission isn't the best place to learn how to use the AI units effectively, start easier and work your way up.

There are charts for both, and it depends on load and altitude a bit. http://forums.eagle.ru/showthread.php?t=133922&highlight=Su+27+turn+chart&page=2 That's a sample. For sure numbers you either need to know what algorithms the sim uses to calculate for specific conditions, or you need to run a flight test program to figure out exact values. It's a lot of test flights and demands very precise piloting, but that will get you the best numbers for what's actually in the sim. For ballpark figures with a moderately loaded plane the charts around the forums are probably o.k.

I can't remember where I found it, either a link here on the forums or by googling but: Navy BFM p-1289.pdf Full title: Basic Fighter Maneuvering Section Engaged Maneuvering Flight Training Instruction T-45 Strike 2012 Textbook for US Navy pilots on how to be a fighter pilot. It also references a: T-45 NATOPS Manual which is probably an aircraft specific pilot's manual. Also any military pilot is going to know the material required for a private pilots license, and have qualified for high performance, complex, multi-engine, and IFR requirements as well. The educational materials for that are fairly widely available, and you could probably get copies through a library or at a bookstore. Specific weapons employment profiles are likely to be hard to come by, and depending on how close the values in DCS are to real values might or might not serve you well in cases where high precision is desired. There are also manuals for specific aircraft floating around on the web, there are Su-25 ones in German, Su-27 ones in Russian and a Spanish translation. Often these are info about the plane that are chiefly useful if you're already a qualified pilot for the aircraft, and not that helpful if you want to learn to become qualified to fly it. For example, how take-off distance changes based on temperature, useful in real life, not so great for a non-pilot trying to learn the fundamentals of flight. Things like rules of engagement and doctrine are also sometime hard to find, though that varies a bit by country and what languages you can read in. I'm pretty sure I've seen at least a summary chart for U.S./NATO ROE classifications linked somewhere here on the forums, but I don't remember where.

For closely spaced tanks the cluster bombs or dispensers are the best bet. For more widely spaced tanks FAB-100s on ripple release or manual release depending on how wide the spacing is. For the cluster munitions you need to hit with multiple submunitions. To do that you need to be extremely accurate, and you need the footprint of at least two of the bombs or dispensers to be over a target you wish to kill. For the normal bombs you need to get a direct hit on each tank you kill, the same is true for the large unguided rockets. Sometimes you can use bombs or rockets on one end of a convoy and pick up another one or two kills at the other end by switching to guns. Accuracy is the primary factor in success though. If you're getting direct hits on the rear and top of the target you can get kills with pretty much anything except S-5 rockets. Misses, even near misses, tend to do only minor non-lethal damage to tanks, even if you use very heavy rockets or bombs. Ultimately, the best unguided weapon is the one that you are best at aiming. I recommend lots and lots of practice with the unguided munitions. Practice is what can make them deadly.

Aside from setting the SAMs to a hostile faction, you also need to make sure that you're putting in the full emplacement. Typically you have several missile launchers and 1 to 3 radar and command units. If you don't have the entire SAM battery set up properly you won't have a functioning air defense unit to practice against. Buk, Kub, Patriot, and Hawk all operate in this manner. For AAA Shilka, Vulcans, Tunguska, and Gepards all use radar, it is self contained and doesn't require other units. Roland and Osa SAMs also posses integrated radar. Also make sure you're turning your Phantasmagoria pod on, it doesn't work when it's off. If things are showing up on the RWR but not on the HUD that's the most likely cause.

The first step is to READ YOUR MISSION BRIEFING AND LOOK AT THE MAP! Not bothering to see where known threats are is really bad practice. Second, use bullseye calls. There are two ways to do this. You can do it the hard way and learn how to pinpoint locations from the info in the radio messages, and plot the units called out on a map of the theater, which is what a real pilot would do. The easy way is to set preferences so that the F10 map shows friendly units, units displayed in the briefing, and units that have been seen by friendly units. It's faster, and the computer figures out the geometry for you. Assume that there are air defenses that your initial sources do not know about, and make your top priority dealing with them. Here there are some options. You can go in low, fast, use terrain masking, use countermeasures, and make single pass on the target before running home. This favors unguided munitions: cluster bombs, dispensers, and S-8 rockets in particular. The idea is to rain down a lot of munitions on a small area so fast that they never have a chance to get a good shot at you. You have to be very fast and very accurate to do this, but it's what might be considered the foundational skillset for a CAS pilot. The other common way to do it is to use assisted visual recon and find threads before you get within range. You can use the Shkval as a magnifier, you can use the zoom function from cockpit view as an equivalent for using binoculars, and at night you can use the LLTV pod (which I suspect works much better than it should) to search for threats. Once you think you've located them all, then take them out one at a time from maximum range with guided munitions. Usually Vikhrs or Kh-29's. Confirm your air defense kills visually, and when you've nailed all of the buggers you can mop up your mission targets very easily. Typically a group of ground units will have 1-3 manpad units, maybe a vehicle based IR SAM launcher, and 0-5 AAA units. They're often placed a bit behind and/or to the sides of the other ground units. Clever and cruel mission designers will trigger thing like MANPADS units getting out of vehicles when the group is approached or attacked, or will hide air defense units in trees or near buildings so that they're harder to spot. The Gepard and Shilka AAA are sufficiently dangerous that they're worth taking out. The ZSU units and vehicle turrets are terrible at hitting planes, and for the most part can be safely ignored if you maneuver a bit. Vulcans are sort of in between, at point blank range they're deadly, but keep a couple of km away and it's pretty easy to avoid their fire as you have time to dodge before the shells get to you. Some of my favored anti-armor anti-vehicle loadouts are: 2x Vikhrs, 2-4 cluster bombs, 2 Kh-29s. (You want to dump the Kh-29's early in the mission to lighten the load, I usually use them on vehicle based SAMs) 2x Vikhrs, 2 submunition dispensers, 2 cluster bombs. 2x Vikhrs, 2 Kh-29s. 2x Vikhrs, 4 S-8 pods. 2x Vikhrs, 2 S-13 pods, 2 S-8 pods. 4 submunition dispensers, 2 S-8 pods. A full load of cluster bombs, single pass, ripple release CCRP mode. So the ideal range really depends on your strategy. Typically in the most difficult scenarios you want to either be at maximum stand-off range, or as close and fast as you can get without running into terrain or being fragged by your own bombs.

Don't use large or sudden rudder inputs above about 100 km/h if the nosewheel is on the ground. Don't slam the nose of the plane down when landing. Don't use full continuous wheelbrakes above 150 to 200 km/h (depending on plane weight). It really helps to have both rudder and wheelbrakes bound to an axis on your control setup. It makes using a light touch when landing the Su-25 much easier. You can try changing the curvature on your yaw axis for your controller, or if that fails, light quick taps on the keyboard rudder controls. For the turn induced blowouts it's a matter of rate, below a certain threshold you can swerve around as much as you like, above the critical threshold it'll rip the tire off of the rim almost instantly. With practice, you can plunk that sucker down pretty hard without popping the nosewheel. Heavy loading on the nose and forces from the side are what tend to destroy the nosewheeel tire, but once you get down to about 100 km/h the nosewheel becomes a lot more tolerant of abuse. At one point I wrote a beginner's guide for the Su-25T in DCS, and there was a whole section on how to taxi with a blown nosewheel. Once you get used to it, it's not really a problem, and the wheel will survive fairly terrible landings. It just won't survive the specific conditions it hates. I haven't reviewed in the past 6 months or so, but historically in DCS there has not been a control for nosewheel steering for the Su-25T, it's just tied to the rudder inputs. Having a nosewheel steering on/off implemented would make avoiding the blown tires a lot easier.

I find the Su-27 to be very easy to fly and very well behaved. Key difference: I never had FC:3, I got the standalone after the new flight model hit. My references for comparison are the Su-25, A-10 C, and P51 modules, and long ago memories of a workaround for GraphicSumulation's hornet 3.0 back in the late 1990's that would let you fly a flanker (though with a C block Hornets cockpit interior). So aside from possible hardware configuration issues, I think most people are just used to a model that wasn't very representative of how a Flanker behaves in the more dangerous and difficult portions of the flight envelope. Aside from botched Cobra attempts I generally find it difficult to make the Su-27 misbehave.

I'm going with some sort of weapons computer code issue. Possibly deliberately simulated code issue. The laser is supposed to be able to lase continuously for something like a minute before automatically shutting off, and if you're willing to risk burning it out you can override the shut-off. When the weapons control system is well behaved you can get 3 shots off in a single pass with no problems. I normally lase manually, as I would for a Kh-25, and most of the time it works. In those cases where it doesn't I cycle the laser manually. It's some sort of weapons system coding issue, not sure if it's mimicking the way the Vikhrs and Shkval work in real life with some sort of deliberate cooldown period in auto-lase mode, or if it's a matter of the system getting confused about when it can or can't shoot due to thinking that the previous missile is still guiding.

Did they increase the Kh-25ML's range? It was my favorite missile prior to the missile flight dynamics upgrade, but afterward it had both a shorter range and slower speed than Vikhrs. I eventually decided that they were so inferior that I just stopped carrying them. I'd either leave the pylons empty or put cluster bombs or canisters on in place of the Kh-25s. The only real downside to using Vikhrs is that the frag effect doesn't always get both the MANPAD and the Com unit, and so in some cases it takes two shots to be sure that the SAM is out of commission.

The way you correct is by using math, but first you need data. To get the data you either have to find it somewhere in the DCS code, or you have to use trial and error with other parameters fixed in order to experimentally determine a close approximation. For something approximating the level of accuracy of a CCIP you need drag data for each different kind of munition you're interested in, and then you calculate a trajectory. It's a lot of work, takes a while, and is one of the reasons that in the WWII era a lot of the early work in computational science was devoted to applications in calculating ballistics. A crude approximation would be as follows: For a fixed: Airspeed, Angle of attack, Vertical velocity, Barometric altitude, Altitude above ground, and munition type. Drop one of the munition of interest, and time how long it takes to fall. To correct for wind then use the wind speed in meters, multiply it by the fall time in seconds, and then correct your aim point by the resulting distance from the target in the opposite direction of the wind. If the wind direction varies with altitude you have to do this as a piecewise function and add the vectors in order to get a final displacement. Perhaps you can see now why this is normally either done before taking off, or delegated to computer control if at all possible. An approach that doesn't involve a large amount of mathematics is to release the bombs at the lowest possible altitude, and release a lot of bombs. If you do this, fly in the same direction as the wind or opposite the wind, and start the first bomb slightly ahead of the target, at least one of the bombs is likely to hit if you have chosen a short release interval for the bombs. **Edit: There are techniques for correcting for wind drift in the A-10 C in DCS, but the ones commonly used involve the plane's computerized navigation and targeting system, and if at all possible GPS guided munitions. These are not available even on the T variant of the Su-25. It comes from an era where the solutions usually involved some combination of slide rules, pre-calculated correction tables, and dropping so many bombs that at least one is likely to hit even if the bombardier's aim is poor.

Seems odd, but I normally get wheels down with less AoA at 235 to 275 km/h, mostly out of habit from bringing back Su-25s with a lot of ordnance still on the wings. I haven't pushed the Flanker's low speed envelope yet, I remember the Grach behaving nicely down to about 180 km/h when light, but as a matter of general practice I look at that sort of speed when landing as just asking for trouble. What were you doing with throttle and airbrake? I normally come in with the throttle at roughly 80% so I have thrust for a wave off if I need it and use the airbrake to bleed speed. Both tend to exert a nose down moment on the plane once the rear wheels are down, so it tends to go nose down as soon as you reduce pitch up input on the stick. Wheelbrakes will also get the nose down, but that's not recommended unless you have a light touch and the brakes are bound to an axis. The gliding along above the runway sounds like ground effect lift keeping you up. Loss of pitch control I'm not sure what the cause would be. The AoA would put the tail very low, so maybe there was some sort of ground interference with the normal aerodynamics? Center of gravity changes from being so light also might have contributed.

You can fly with the keyboard, but it's definitely a bit trickier than it is with a good stick. Aside from input hardware considerations and odd/multiple bindings (in particular if you're getting keyboard input that conflicts with things bound to mouse, laptop mousepad, or numberpad, etc) the Su-25 variants are very well behaved if you stay within their limits. Make really sure the plane is trimmed in level flight before turning the autopilot off. It can fight you pretty hard if it's trying to counter pilot input. Other things are make gradual smooth control inputs, and try to stay at 15 deg AoA or less as a new pilot. Loss of control occurs around 20 deg AoA. Also try not to drop below about 350 km/h IAS, 400 is even better. The plane gets a bit less forgiving at the low end of its speed range. Flaps in maneuvering position are a good idea if you're below 450 km/h and want better control. It's very unlikely to be wind or turbulence. One question, are these training missions where you've dropped heavy ordnance from one wing, but not from the other? Unbalanced loading can get you a bank of anywhere from about 0 to 60 degrees, depending on which pylons are loaded in an unbalanced configuration. Pretty easy to correct for with a stick, but I could see it being pretty crazy with keyboard controls. If it is unbalanced ordnance the wings level/emergency autopilot can get you trimmed out if you maintain reasonable speed and fly straight after weapons release. Turn it off as soon as you're stable and then you should be able to maneuver more easily (you'll have to re-trim if you drop the rest of your load on subsequent passes).

The thrust is more or less working as intended. At about 80% throttle when increasing thrust, or at about 72-74% throttle when decreasing throttle from above 80% the nozzles on the engines close/open. When they close, the thrust increases greatly. This is supposed to reflect the real behavior of an Su-27's engines. Happens on the ground and in the air. For taxiing you just have to anticipate. Throttle up to 80%, and after half a second or less, throttle down to 70%, even if you haven't started to accelerate to a large amount. If you wait until you see the acceleration, you'll have more than you want, as it takes a few seconds for the engines to spool back down after you reduce throttle low enough to cause the nozzles to open. The other FFB stuff I know nothing about, but a lot of people have had trouble with the 27's trim.

If the flaps are to the rear of the plane's center of gravity, the additional lift they provide when deployed lifts the rear end of the plane, providing a moment that rotates the nose down. For the automatic flap extension, the flap changes are not always from low deflection to maximum deflection, so the effect may not be as pronounced. The autoflaps also tend to be deployed when the pilot is making stick inputs great enough to compensate for the autoflap's pitch effects, so though the effect is there, you're much less likely to notice it. On landing approach you're in a fairly stable state, and inputs are mostly small and gradual, so it doesn't take much of an effect on plane handling to be noticeable.

The Su-27 is pretty easy to land without the chute, and without popping tires. At least I find it so compared to Su-25 variants. Don't land too fast. If you're above 320 km/h at the runway threshold do a go-around. Reduce throttle. Depending on conditions and your confidence in how well the landing is going, you should have 80% throttle if you think you need more speed and lift, or about 70% throttle otherwise. If you're overrunning landings a lot I'd try 70% or less. Don't land too far down the runway, you want rear wheels down with about 2/3 of the runway left, if you get them down solidly after the halfway point go around for another attempt and make your approach a bit lower on glideslope. Use the airbrake. It should get you down from about 290 km/h to 230 or so pretty quickly if rear wheels are down and throttle is cut to idle. At about 200 - 250 km/h hit the wheel brakes. Make sure your nosewheel is on the ground before you do this. At the high end of this speed range you might want to repeatedly tap the wheelbrake key instead of pressing continuously, as you might pulse the brake of a automobile in wet or icy conditions to prevent a skid. Below 200 km/h it should be safe to use full continuous wheelbrake. For braking chute use, make sure all wheels are on the runway, throttle is 70% or less, and then deploy the chute.

Ok, trim controls for the SU-27, Basic design is tailored for a 4 way hat switch. There's also a setting for separate rudder trim, that would probably be best suited for a rocker switch. (haven't tried the rudder trim, not sure if it works). There's also trim reset, which would get a button of it's own, or could be assigned to the button press on a 5 way hat switch. (again, haven't tried it not sure if it works, I know it doesn't in the Su-25, but perhaps it does in the Su-27) If you're trying to trim in the same way the helicopters do you're going to get weird results, they have very different trim system controls than the fixed wing aircraft do.

I haven't checked a manual recently, but if I'm not being misled by my memory I believe that on the shared HOTAS design for the real Su-27, Su-25, and Mig--29 one of the hat switches on the stick is for trim. I believe that somewhere on the ED forums there's a thread with a diagram that has most or all of the Soviet HOTAS controls labelled.

They're not working in the "Difficult" landing tutorial mission, I haven't hopped into quick missions or mission editor to do a detailed check though.