Bushmanni

That's great to hear. My idea about SRS was that if it could make recordings with sync data included would you be able to take advantage of that to automatically sync the sound file with the acmi. This is something you and Ciribob would need to consider together to make it happen (ie. Ciribob makes the recorder and you the player.).

SATAC Registration: SF Squadron http://dcsfinland.fi/sf-squadron/ pilots: Bushmanni Ocelot Razer Kapsu Juuba Sykloni Farrago RedShot Everyone will be flying F-15C. When can we have the mission file available? One concern for me is that the mission is built by someone who is participating in the competition and hence his team gets head start in training as they know the precise area where the battles are fought. In this case I'd like to have the precise combat bubble position and size published as early as possible so we can factor it in in training. If the battle is fought over water or flat land then it's not an issue but in mountains familiarity with the terrain can be a factor. The "netcode" setting only affects the extrapolation algorithm ie. it doesn't have any change in the data that is traveling between clients and server. It only affects what happens on your own machine. In BVR the new algo likely improves missile Pk and helps keeping tally in laggy situations but other than that it effectively disables gun sight in F-15 and completely destroys BFM in any situation. In a setting with few players and good connections the old algo is superior until the new one is fixed.

How hard it would be to include possibility to play back a sound file (and maybe multiple files from multiple channels, that you can selectively mute if needed) during ACMI playback? What I'm after is having comms playing out at the same time as action is unfolding so we could also debrief and analyze comms technique. You would also need a method to set a synchronization point for the sound playback. I was also thinking about integration with SRS so you could automatically record your comms in SRS and have them synced with ACMI in Tacview automatically. This would of course require collaboration with Ciribob.

That leaflet took it's info from wikipedia. (says so at the bottom small print)

Something wrong with the new extrapolation algorithm. Planes look like they have negative AoA when turning and other funky stuff while maneuvering. Besides looking like having negative AoA the infobar in external view also show negative numbers for AoA when turning tight. Missiles are also desynced with the new algorithm so enemy missiles regularly seem to lose track and then you suddenly blow up anyway. Desync in AoA and missile flight path is a serious problem for doing any kind of BFM. If you use the old extrapolation algorithm planes and missiles seem to fly like they should and the AoA is synced correctly over the network (pilot and spectator see the same AoA).

Some people are larger than others and the world also looks different size for them because of that. If you happen to be larger or smaller than average VR world will also look larger or smaller than what you are used to. This of course assumes that the world scale is set for average user. The main parameter is IPD and eye height is also important if you are doing VR while standing. Naturally if you aren't presented anything familiar which size is known you can't ascertain the "real" size of the objects and world.

Good job with the blog, garrya. All the english language info about radars, aerodynamics is either professional stuff with too narrow scope and too much details into one specific system or it's a 10kg 100$ brick meant for students aiming to be professionals or if it's meant for non professionals it's too dumbed down to be of any use to really understand anything. You are striking just the right balance.

Good job with the video and commentary. I hope we will be getting more of those.

garrya, is the blog written by you?

Flanker is not a bad plane, it can give a good challenge to the Eagle when flown properly, although Eagle is better in most respects when flown by a pro. While Flanker has advantages over the Eagle that the Flanker fanboys (or propagandists) like to make noise of, the advantages the Eagle has over the Flanker actually matter more. Performance at high speed and high altitude and high max G load are all good for BVR. While Flanker has good numbers on paper they come with caveats that make the real story much less impressive. Eagle and Flanker are both nominally 9G platforms but Eagle can actually withstand it on a relatively much higher weight limit. Both can fly stupid fast but Eagle can reach high speed faster and uses less fuel in doing so which makes this capability more useful tactically (same goes for altitude). In BFM Flanker seems to be the better turning plane but Eagle actually turns pretty well also but it can also accelerate, climb, pull G and decelerate much better than Flanker. Smart pilot can use these advantages to overcome the turning disadvantage. Some of your problems are probably due to not understanding how to squeeze max performance out of the Flanker. Or the Eagle was flying low on fuel and without external stores which really gives it a performance boost. I suspect 18000km/h (not possible in DCS) is a typo and was meant to be actually 1800km/h (easy to do in DCS). None of the planes you give as example has T/W ratio over 1 at max T/O weight. The combat payload where the stated T/W ratios occur are also not necessarily comparable between planes. Flanker especially can carry lots of internal fuel that will handicap it severely if there's too much of it. The records set by both planes were flown by modified planes and the Flanker had more modifications done compared to an operational plane. So an operational Eagle should beat an operational Flanker in climbing contest.

You need scripting for that but fortunately there's a script already for it. http://forums.eagle.ru/showthread.php?p=1807492#post1807492

Would the null tone happen also with newer FM modulated seeker heads or is it only feature in the older AM modulated seekers? Some docs describing the the seeker modulation: [ame]http://www.dtic.mil/dtic/tr/fulltext/u2/a286117.pdf[/ame] http://wiki.scramble.nl/index.php/Sidewinder_article#Amplitude_Modulated_tracking http://www.ausairpower.net/TE-Sidewinder-94.html Basically AM seeker doesn't give any signal to the seeker steering system when it's pointed directly at the target while FM modulate seeker does. To my knowledge the audio tone from a Sidewinder is directly taken from the seeker steering signal. AM modulated missiles should also give different tone than FM modulated missiles besides the null tone difference. AM modulated seeker gives a louder tone when it sees a target while FM modulated gives a louder and higher pitched tone.

Nice video.

A small bump is not a problem. For example F/A-18C has it. It so small though that you only barely notice it so it doesn't have any effect on precision in the center. I would actually prefer having it as then I can tell precisely when I'm commanding zero roll with feel alone which is important when maneuvering at the edge of the envelope. On the other hand having separated axes doesn't mean you have a bump at the center, only that the forward-aft force gradient and left-right force gradient are independent. If the force gradient doesn't have a bump you wont have it.

I'd like to see the official documentation describing it like that.

Is there going to be an ACMI available at some point besides the video?

Important note: Corner speed gives you the best instantaneous turn rate. The best sustained turn rate usually occurs at different speed (higher than corner speed for fighter jets). EM chart is the usual source for corner speed and best sustained turn speed. These speeds also depend on your weight so there's no magical single speed that fits all scenarios. Besides performance related optimum speed being weight dependent, the turn rate curve where you find that speed might indicate that the optimum speed might not be optimal for your tactical needs. For example you might get lots of extra degrees by starting slightly faster than corner speed without serious drawbacks (depends on the plane). Or you might notice that you get almost optimum sustained turning performance in a larger speed zone so overly optimizing you speed isn't worth the effort (depends on the plane). Unfortunately there's no simple answer for the OPs second question as all simple answers would be invalid and useless. The practical answer is to learn few optimums speeds for different typical scenarios and then interpolate in your head for the situations in between. The use of optimum speeds comes down to two types of BFM flows, nose-to-nose and nose-to-tail. When both fighters turn in the same direction you have nose-to-tail flow where turn rate is important (sustained turn speed more specifically as you need to pull a long turn). When fighters turn in opposite directions you have nose-to-nose flow where turn radius is important (generally achieved by starting with max performance turn and slowing down to minimum radius speed which is typically relatively close to minimum level flight speed). You want to optimize your flying speed for each flow to get more performance out of your planer than the bandit. Getting into the bandits six is all down to your management of the flow geometry and getting more flow relevant performance out of your plane than the bandit. Often you need to anticipate the change in flow (initiated by the bandit or you) to get a jump start to beat the bandit. When you throw in energy management you also need to understand optimum speeds for vertical maneuvers and climbing. BVR fights can take a long time and your fuel is usually just as important as your missiles for staying relevant for the fight. So in BVR you also need to consider fuel economy and different climb profiles for attaining altitude, range, speed or energy in efficient or quick fashion. These profiles are also weight and drag dependent. If you look in a real flight manual of a fighter plane you will see it's filled with performance charts and they are there for a reason. Fortunately you don't need to memorize all of them for combat but you need to look through them and figure out some rules of thumb for your own use. You can make your own EM charts if you learn lua scripting and some elementary physics required to do the calculations for extracting the turn performance data from flight test. Besides that your options are real world data from the internet or someone doing the flight test for you.

The linked pdf has some pretty good stuff for survival against fighters (and helicopters). [ame]http://www.dtic.mil/dtic/tr/fulltext/u2/a071904.pdf[/ame] Practical demonstration: [ame] [/ame] When the fighter comes in at shallow angle you can't spoil his aim effectively with maneuvers so it's better to just shoot back if you can and maybe manage to scare him to abort the attack. If you are flying Ka-50 that kind of attack is not safe at all for the fighter (as long as the Ka pilot can use his chopper to its full abilities).

Antennas radiate and receive power also in sidelobes besides the mainlobe. While the mainlobe is the strongest lobe it probably doesn't cover even half of the total pattern of the antenna but in any case the sidelobes cover significant portion of the total antenna radiating/receiving pattern. When you fly low the sidelobes pointing below horizon will emit power to the ground and also receive the echoes. Signals from sidelobes will get mixed in with the signals from the mainlobe. Sidelobe energy has less distance to reach the ground and there's multiple sidelobes pointing to the ground so they can have pretty strong signal despite the sidelobes being much weaker than the mainlobe. The sidelobes also point in various directions so the echoes from ground come from various distances further messing up the signal. Unless the target echo coming from mainlobe is stronger than the combined echoes from sidelobes for the target distance it gets drowned out by the sidelobe noise. There are techniques to suppress noise from sidelobes and from ground in general but MiG-21 radar uses only some primitive ones. Still even a modern high tech radar will suffer at low altitude to some extent.

Modern doppler radars can see you even at ground if your speed is high enough to take you out of the ground echo (notch) filter. Keep your speed below 80kts (145 km/h) and stay lower than the airplanes searching for you and they won't see you with radar. When the radar searches above horizon it will disable notch filter so you will be seen regardless of your speed. Basically you don't usually need to be lower than about 20m as very few fighters go even that low and only for a brief time. Your speed is more important for hiding. If you fly below 9 meters you will leave a dust trail that is visible for long distances so getting very low isn't good either. There's variety of ways to detect a chopper in MP. Once someone finds you they can call in fighters to look for you if they can't kill you themselves. For example optical sensors in A-10C, Su-25T, Ka-50, tanks, etc. can see you from very long distance if you happen to wander in their FOV. During daytime fighters can simply search and see you visually even if you can hide from radar. The chopper itself isn't usually too visible due to camo color but the shadow is easy to spot above flat terrain unless you hide it among trees or buildings. If you are attacking an airbase the fighters still on the ground starting up might be able to see you skylining when you peek above hill and know exactly where to look for you once they are airborne. Use something as a backdrop to avoid skylining. Forested hill or buildings would be the best. Russian planes have EOS that can see your heat signature so going slow wont help against it. It has only short range though and if it locks you you'll get warning from its laser range finder. You can hide from EOS by landing and shutting down your engines.

Target bearing is the direction of the target from you ie. if you point your nose to the said bearing the target will be exactly in the direction of your nose. Yes, 17R means the target is flying almost directly at you but little to the right.

Wikipedia article on PRF is just confusing. First of all you need to know that high PRF mode is different from low PRF (and med PRF) in many other ways than just the PRF. Most important secondary difference is pulse width and duty cycle which is the ratio of pulse width to pulse repetition interval. Since high PRF has small unambiguous range detection capability it has to use different method for ranging than direct pulse flight time measurement. Essentially high PRF mode encodes each pulse so you can later identify the original pulse from the reflection and then calculate the pulse flight time. This method reduces range resolution. As you now use a different method for ranging echoes, you can ramp up duty cycle as much as you want (all the way to 50%, ie. the radar spends equal time sending and listening) to output as much energy as possible. This gives the high PRF the long detection range it's famous for. You also get the best frequency resolution due to high PRF and therefore good clutter rejection. Low PRF has small pulse width and large pulse interval hence low duty cycle. Low duty cycle is essential for large unambiguous range measurement capability. Low PRF mode can't use doppler frequency detection so it's essentially a pulse radar mode (like the radar in MiG-21). Hence it can't filter out ground returns by doppler shift either. You can still detect targets if you set up the geometry so that ground clutter is minimized (target above horizon and radar sufficiently high above ground) or target is so close that the target has stronger echo than the ground. You can also see targets below horizon if the "ground" doesn't produce much echoes like over calm sea. What you see displayed is something like a weather radar or marine radar. Because of small pulse width LPRF has superior range resolution. On the other hand because of small duty cycle it has low average power and hence low detection range. Range resolution plays a role when trying to detect two targets flying close to each other. When you have good range resolution, the targets need to fly much closer to be detected as single target compared to if you had bad range resolution. DCS doesn't model resolution cells so all radars have infinitely small resolution cells and therefore you cant hide your presence by flying close to another plane.

My experience with hollow structures in general is that they tend to completely fail soon after they start to give in instead of permanently warping. You can have only very little warp in a small stretch of structure and if you want to have a large bend you need to distribute it along a long distance (like you do in pipes). I would think semi-monocoque wings behave somewhat similarly?

How are the load carrying structures inside modern fighters wings built? If they are hollow sheet metal structures they would behave different from solid metal bars.

Amongst the wind noise you can hear clank and clonk noises like railroad car going over welds on a track. I don't know what the sound actually is but it's annoying.