DarkFire

Agree, plus I think that upgraded F-15s would make a lot of sense for allied air forces. The RAF for example would probably make good use of some upgraded F-15E's when the current fleet of GR4's reach the end of their airframe fatigue lives, particularly as the current government seems unwilling to pay for the Typhoon to receive the full A2G capability that it was designed to have.

Have any countries signed up for the Silent Eagle program? Shame if not. I would imagine that for 10% of the cost of developing the F-35 the Eagle could easily be improved to a level where it would be absolutely able to take on everything currently flying and anything that will be flying in the next 5 years.

There is a crosswind but other aircraft are certainly affected by it. On the VA server the F-15s spawn at Krasnodar Pashkovsky. The wind is usually 4 m/s at I think 354 degrees. In my Su-27 I'm constantly tapping the rudder to keep it steady on takeoff. Su-33s and MiG-29s spawn at other locations. The server has dynamic weather which could be why you're seeing less wind during takeoff in those aircraft. All that being said, in my very limited experience in the Eagle it does appear to be more effected by crosswind that some of the Russian types.

I've read that somewhere. Apparently the EF-2000 is supposed to be able to accelerate in a 9-G turn. As for the F-15, wasn't there some sort of proposal a few years ago to give it a new wing & other goodies?

Location: London, England. Native Language: English. Other Languages: Welsh (sounds vaguely Celtic for the uninitiated). Accent: British. Experience: Appear in several published & to-be-published campaigns (Enemy Within, Museum Relics) and various single missions. Recording Equipment: Semi-pro microphone attached to dedicated sound card. Use Audacity. Voice: Male, medium tone / pitch.

Just tested it and... I have a new favourite control! :joystick:

Is there??!!!? As in ctrl-T? Damn, I thought that had been removed!! And here I've been raging for hours at various times against asymetric trim issues caused by nudging the stick in ACS mode, when I could have solved the problem! Are you sure there's a trim reset control?

The Su-27 doesn't have a trim reset function. Resetting trim might have had some effect in (very) old versions of the game - by that I'm thinking LOMAC or FC1 - but not any more.

Don't necessarily disagree with that but what do you mean by 'agile'? Roll rate? Slightly O/T: I can totally understand why McDonnell Douglass called their aircraft "Eagle". I read a book about them after hearing that the Dutch police are training eagles to catch drones in mid-air. My immediate thought was that propellers on a drone would hurt the eagle's feet. Nope. Turns out eagles are the avian equivalent of honey badgers: flying death machines!!

Definitely. Not sure how ED could model the stick shaking for non-FFB sticks (sound possibly?) but even more useful would be the stick limiter. If the real Su-27 has one it'd be really nice for our DCS Su-27 to also have one.

Managed it. Here then is the traditional form of the altitude v maximum mach plot for the Su-27: Method: it appears that for most graph types the data to be displayed on the X-axis is always in an earlier (further left on the table) column than the data to be plotted on the Y-axis. Why this is the case I have no idea. A very large thank you to Weta43 & Ironhand for pointing me in the right direction. Frankly whoever wrote the built-in help files for Excel 2016 can [REDACTED] with a well manicured goat. :furious: :ranting: :bash:

Ah, awesome, thanks very much. I tried the first few suggested methods & the results were... Strange. Ironhand - I think you're right in that the chart type I chose is limited in some way as to the data presentation. I'll have another play later with different chart types & see what I can brew up.

Thanks. I'm using Excel 2016. Zipped work sheet attached. Su-27 Flight Characteristics.zip

Thanks :) I know, normally graphs showing this data have the G data plotted on the x axis. I've tried doing this but so far Excel is stubbornly refusing to comply. Once I figure out how the hell to bend Exel to my will I'll post the graph as it usually appears. The acceleration tests are something I'm working my way up to. That's a hell of a lot of test flying, but I'll do it eventually :) Unfortunately the Su-27 doesn't have a fuel flow meter. There are however ways to make an educated guess. The most efficient cruise throttle setting is around 85%. It varies between 83% and 87% but if in doubt 85% is always a good choice. Above this setting the speed increase with increased throttle ceases to be linear, which would also be worse for fuel economy. Have a read through this thread: http://forums.eagle.ru/showthread.php?t=151731&highlight=su-27+range If you look closely at the table on page 1 of that thread you'll see calculated fuel consumption values for different altitudes, measured at the best cruise throttle setting for any given altitude. In terms of best speed, the higher you go the more fuel efficient the aircraft will be. Don't think that you'll need to increase throttle at higher altitudes either: the Su-27 will happily cruise at 14,000 metres at 85% RPM, though your IAS will be so low that anything other than cruising in a straight line is completely impractical. However, the problem is that the autopilot on the Su-27 is bugged. If you engage altitude hold mode at any speed under 550 Km/h IAS the aircraft will become unstable and a nasty yaw oscillation will set in. 10,000m is the highest altitude at which your IAS in anything other than afterburner is above 550 Km/h. Your maximum range with full fuel and a full missile load is of the order of 1,500Km when cruising at 10,000m so in terms of best cruise speed I'd recommend anything between say 7,000 and 10,000m altitude. In terms of climb performance, I don't have the figures to hand but I think I remember reading that best climb speed is 0.85M. Personally after takeoff (maximum dry thrust) I maintain a vertical velocity of under 10 m/s until I reach ~0.90M. At that speed you can climb at anything up to 50 m/s vertical velocity without any appreciable drop in forward speed until you're way above 8,000m. This makes for an efficient and fast climb to cruise altitude. Hope this helps :)

PURPOSE OF TEST: Having tested and analysed cruise performance for the Su-27, and having calculated the dry thrust performance envelope as described on page 5 of this thread: http://forums.eagle.ru/showthread.php?t=147556 I wanted to re-visit the performance tests and see what the maximum possible speed of the Su-27 is using afterburning thrust at various altitudes, measured in steps of 1,000m. TEST CRITERIA: 1. Standard DCS day with no wind, no clouds & no precipitation. 2. Aircraft condition for each test was 100% fuel, no expendables, no ammunition, no weapons loaded. 3. Starting airfield was always Batumi (or roughly above it, see below). 4. For tests at 1,000-6,000m altitude, I started on the runway, took off, climbed under military thrust at ~0.95M to cruise altitude and engaged the altitude hold mode of the autopilot. I then allowed speed to stabilise for a short period before increasing thrust to maximum afterburner. I then let the aircraft fly until I got a bingo fuel warning, at which point I throttled back to 90-95% RPM and allowed the aircraft to slow down. Each test flight was ended about a minute after the bingo fuel notification, except the 16,000m altitude test, during which I decided (on a whim) to carry out a rough field landing. 5. For test flights from 7,000-16,000m altitude, I started in the air at the relevant altitude. Once I managed to stabilise the aircraft and engage altitude-hold, I once again moved to maximum afterburning thrust & allowed the aircraft to fly until I got the bingo fuel notification. At the end of each flight I saved the relevant track. Data was obtained using TacView 1.4.3 64-bit Pro edition. Data was then saved on to a MS Excel spreadsheet which I also used for graphing purposes. Each flight was performed using DCS WOrld 1.5.3.4278 which I think is the latest version as of today (02/05/2016). TEST RESULTS: This is a table of the raw data provided by TacView as described: Plotting maximum IAS against altitude gives this graph: Note the decrease in maximum IAS from 1,000m to 4,000m. altitude. I'm theorising that this observed reduction is caused by the airframe being speed limited by drag caused by air density. Plotting maximum TAS against altitude produces this graph: More or less as expected, maximum true air speed increases up to ~12,000m after which it slowly drops down. I postulate that the drop in TAS at very high altitudes is probably caused by the drop in engine thrust in the thinner air. Finally, plotting maximum Mach against altitude produces this graph: This is again consistent with the general shape of such graphs published for other similar aircraft. Note though the maximum mach at 12,000m altitude: 2.62!!! :shocking: I believe that this is marginally faster than the F-15C is capable of in DCS World. I don't really fly the Eagle but I've seen a maximum speed figure of Mach 2.606. Obviously the real F-15 is capable of going significantly faster than this, and what little published data exists for the Su-27 suggests that its maximum speed at altitude is in reality Mach 2.35, so it appears that something somewhere could do with a small adjustment. Whether it's the aerodynamics of the DCS Su-27 or the atmospheric model I don't know and can't tell from the observed data. In any case, our DCS Su-27 is indeed a very fast machine. It's also worth noting that despite the fact that for test flights above 7,000m I started in the air, it's absolutely possible to re-create the same tests from a runway start. Vmax isn't limited by fuel quantity in any of these tests. OBSERVED ANOMALIES: In carrying out these tests I did observe some anomalous things, both in the way that the aircraft behaves and also in DCS World itself: 1. Bearing in mind that there was no wind during any of these test flights, I've observed that the thin cloud layer up at around 12,500m appears to have default wind associated with it. In areas where clouds actually exist at that altitude (it is in fact patchy) I experienced small but noticeable variations in speed, despite the fact that I should have been at a steady Vmax. Additionally in other flights I've noticed what appeared to be wind shear, buffeting or even turbulence in and around that cloud layer. 2. When decelerating from Vmax down to cruise speed, at some altitudes I observed a pitch oscillation between ~1.7M and ~1.3M. Whether or not this oscillation was present appeared to depend on how quickly I retarded the throttle in order to slow down. Taking it from AB instantly down to idle nearly always produced the oscillations, but retarding the throttle much more slowly never did. I've no idea what causes this, but I'll speculate that maybe it's caused by some weird engine aerodynamics caused by a large difference between actual and commanded RPM. 3. Between 5,000m and 9,000m the DCS Su-27 is capable of "super-cruise" at 95% RPM. By "super-cruise", I mean a stable speed above Mach 1. I'm aware that there are other definitions of what super-cruise means but let's leave that for another discussion. Nothing I've ever read suggests that the Su-27 ought to be capable of it, but who knows? Maybe with a clean airframe it is possible. 4. None of these tests are ultimately realistic because the actual Su-27 pilot's manual restricts flight at maximum speed to 5 minutes or less due to canopy heating concerns. 5. Finally, all the ACMI files, the track files and the Excel work sheet are all uploaded and can be downloaded from this link: https://onedrive.live.com/redir?resid=D3293A5ED5656179!5068&authkey=!AB1JRcaem0b1hXU&ithint=folder%2cxlsx I hope all this is of use to the Flanker pilots amongst us...

No idea what the official plans are, but there are very few features of the in-game Su-27 that aren't mentioned in the manual. In that respect at least it's quite complete.

Maybe it simulates the combustion chambers being flooded with fuel? Not sure to be honest as I've not flown in the Eagle enough to experience this...

Ah, maybe I should have been more clear - I meant in game terms, rather than real life. 40K+ for a real F-15 would make perfect sense. Probably would for the Su-27, Mirage and many others too. I also agree that you can have > 400 Kts IAS up there, but at what throttle setting? I can envisage a scenario where you'd absolutely want to get as high and as fast as possible when e.g. intercepting Russian strategic bombers coming over the north pole to attack the CONUS, i.e. a defensive SIOP scenario, but for more tactical engagements such as a deployed in-theatre fighter sweep, escort, CAP etc flying at military thrust or even some AB stage would needlessly waste fuel. Please note I wasn't having a go at you with regards to the astronaut comment - if you want to fly realistic profiles then good, I like to do the same thing, but there are plenty of people who fly in a similar way not for that reason but because they think it will maximise their missile engagement range, without understanding the associated limitations of flight in that sort of regime.

It's well known that all missiles have artificially high coefficient of drag, which results in them losing speed and energy unrealistically quickly. ED's position is that tuning missiles for realistic ranges at low-medium altitude gives them extremely unrealistically long ranges at high altitude, for example the old 170Km kill-shots it was possible to get back in LOMAC / FC1 days with the R-27ER. My response would be that nobody conducts missile duels at 45,000 feet. IAS for both the Su-27, F-15 and the M200C is so low at that altitude that conducting a turning fight is both impossible and unrealistic anyway. Personally I'd much rather see realistic missile behaviour between ground level - 10,000m altitude and accept that the trainee astronauts will occasionally be firing from longer ranges. That tactic is easy to counter anyway.

The T version is much more capable: it can properly use precision guided weapons via the electro-optical targeting system, it can automatically drop bombs using the autopilot and is currently the only aircraft in DCS that can perform dedicated SEAD. The Su-25A can still be effective but is older and much more limited in capability. Given the choice I'd take the Su-25T every time.

I still genuinely don't see that the airframe G limitations are a real issue. At cruise speed (~85% RPM) with 80% fuel and a full A2A missile load it's still perfectly possible to slow to corner speed with a near-maximum STR turn and then perform a near-maximum STR turn without breaking the aircraft. I have broken it under these conditions but it was entirely deliberate and I had to repeatedly exceed 9.5G to do it.

In all sorts of ways, radar and flight model being the two most obvious, the AI doesn't have the same limits that players do. It appears that the AI can automatically detect you at maximum possible range.

Keep practising. Eventually you'll gain situational awareness in terms of when to dive/notch & develop a sort of 6th sense about when an AMRAAM is probably headed your way. Even with diving, notching & chaffing, survival isn't guaranteed.

Thanks, definitely worth knowing.

The "*" key on your keypad will zoom in your view and cure the problem. For some reason DCS world gradually zooms all the way out whenever you start a mission. Zooming back in will solve the problem for you.