Bushmanni

This looks pretty neat. I have experienced couple seat tilting systems and they were simply awful as the tilt was about 0.5 sec behind what happened in screen and therefore the effect felt as very disturbing random shaking. I can't imagine a suitably high grade tilting system can be made that would be fast enough and not injure the user and that would feel as lateral acceleration instead of tilting. As such I have been hoping that this kind of systems would be developed. How much latency there is in the system? I'm pretty certain it can be made pretty fast but how hard it would be, what it would take? Having some kind of sensory feedback through skin would be very useful even if it doesn't feel exactly like the real thing as long as it's not uncomfortable and the difference between different directions and strengths can be felt and response is fast enough.

Go into INFO mode in ABRIS, scroll the cursor over DL target and press INFO again. It will then show the exact coordinates of the DL point besides some other useful info.

LOL

I'm not trying to understand the big picture, ie. energy principles and conservation of momentum. etc. that are usually used to describe how the jet engine operates. What I want to know is what is pushing the engine forward, ie. how the exhaust and air molecules bounce off the surface of the engine so that the net force exerted makes the engine move forward instead of just sitting in there. As an analogy aircraft wing produces lift by pushing air downwards so that the impulse imparted on air is equal to gravity but the actual force pushing the wing upwards comes from air molecules hitting the bottom surface with more speed and/or more often than the upper surface ie. due to pressure difference. The impulse imparted on air and the pressure differential are two sides of the same coin as you can't have one without the other. What I'm trying to understand is the pressure distribution inside the engine that actually pushes the engine. It's obvious that this isn't a self evident problem to figure out. The turbojet engine needs some pressure in the burn chamber and the compressor will create it but there still needs to be some way of keeping it there for the engine to work which means you need some constriction for the flow besides the turbine. Obviously the afterburner can provide this backpressure even if the nozzle is opened up and there's either more pressure on surfaces that push forward or less at surfaces that push aft (ie. "pull") because the engine is pushed forward more when afterburner is on. In order to have more pressure pushing forward you would need to have some kind of mini nozzles in the afterburner where the ignited jet fuel is ejected. Otherwise the pressure would push air both aft and forward which would disrupt the operation of the engine. The nozzle theory isn't able to explain either how the required backpressure is generated as the nozzle is opened. As I'm pretty certain there ain't any nozzles that leaves only the option of less pushing backward. When you open the nozzle more there's less area for the pressure inside the afterburner to push the engine aft. The opening of the nozzle would reduce the pressure differential at nozzle (the required backpressure for the engine) unless the flow speed is accelerated at the same time by expansion of the exhaust gases. Higher flow speed at the nozzle creates the same pressure differential with larger nozzle area. As I'm thinking about this I can't but wonder how on earth the guy who invented jet engine was able to come about with such an idea. That was some out of the box thinking.

I have experienced a mysterious Vikhr guidance failure once. There was no excessive wind and laser was working just fine. The missile flew as should for a few kilometers and then suddenly just flew off the beam like if the laser had stopped emitting but the range reading was still there and laser was working after this mishap. I tried firing more missiles and all of them flew all over the place after certain point. My friend hovering besides me was able to engage all his targets just fine. I know from experience that this mid-flight guidance failure happens if you fire the Vikhr without lasing for range first but that wasn't the case. Maybe there's a bug that makes the laser time out as if there wasn't range reading in the first place?

Griffin, thanks for the video link. So how I understood it is that compressor pushes air forcefully through the pipe and it's the main culprit behind air going from intake to exhaust. The pressure inside the engine is created by the compressor and the reason why the pressure keeps up is the rapid expansion and acceleration of the gas in the burner ie. expansion makes up for the "leak" through the turbine. As aerodynamic forces act on objects through surface pressure it's mainly the pressure on compressor blades that makes the engine and thus the aircraft move forward. Now with this I think I also figured out the afterburner. I spent maybe three hours trying to explain how I think the pressures inside afterburning engine work but couldn't make it simple enough that other people would be able to follow my thought and understand what I wrote. The essential point of my idea is that afterburner doesn't create "pushing pressure" but instead reduces "pulling ones" by allowing larger exhaust nozzle area while still providing same backpressure for the engine as smaller nozzle without afterburner. Maybe this is enough that someone who knows can tell if I'm at the right track.

I had to try out this right away. Took some time to figure out how the sling loads work and after that how to stay over the cargo net long enough for it to get hooked. After nearly crashing the bird twice with the first sling load and completely trashing the cargo I smashed the second cargo net to a building just to see what happens and to get "revenge". Third time I managed to move the load to where I wanted somewhat intact.

If you look carefully my controls indicator you can see that first I apply rudder to the direction of the bank to keep the nose down as I pull back on the cyclic. At some point the nose drops a bit too low and I move rudder opposite direction to the bank to get it up again. You will have to start with rudder to the direction of the bank but after that you move it where it's required to control nose position. If I had managed to keep the nose at horizon at the later part of the turn I would have been able to stop even faster as I had nose down when leveling the chopper which means I was accelerating for a moment. Nailing a perfect max performance quick stop is hard and especially if you try to maintain your altitude during it. If you make it gentler like in the NH90 video it will be safe and even look pretty. In order for VRS to develop you need to have fast enough flow through the rotor upwards and then apply power to try to reverse the flow. Instead of flow reversion a donut ring vortex develops. If the flow goes fast enough sideways the donut vortex can't form as the vortexes are swept away from the rotor by the flow. As long as you have enough lateral speed (>~50km/h) it's impossible for VRS to form. You can try to make the break turn all the way until you stop and see what happens when speed goes under 50km/h.

What I have been wondering is how the jet engines provide thrust in only one direction instead of both aft and forward as its just an open pipe with some fan blades inside. How the pressure inside pushes the gases in only one direction? Is it accomplished just by shaping the burn chambers in a clever way or is there some other things to it?

At first the project proposals that concluded in A-10 were turboprops but when a suitable turbofan engine became available it was chosen as the powerplant. I don't remember why the change was made.

What Tsumikae described is the fastest way to stop if you don't need to stay low, but you might not want to pull full 90 degrees nose up, about 50 will do it just fine and hold it a bit longer. It's a good maneuver to have in your bag of tricks. It's good to know and remember one important thing regarding hard turns and decelerations which is that rotor usually goes into autorotation during these maneuvers and soon after engines go to idle and when you stop the maneuver you will suddenly need hover power which the engines can't produce for a few seconds but until they spool up again. Rotor RPM will droop for a while and if you are at low altitude after stopping you will hit the ground usually hard enough to break something. To mitigate this you need to come out of the autorotation part early enough before stopping to have power available in the hover. Now to the quick stop and flare maneuvers: I managed to pull of good examples (well at least I'm satisfied with them) of said maneuvers and found out that fully loaded Ka-50 isn't able to pull 30 degrees pitch during flare without problems. Essentially the engine won't be able to catch up when stopping and you won't be able to keep the nose pointed forward during autorotation because of reduced yaw authority. The nose direction is more of a show-off problem as sideslip will just make the chopper slow down more effectively. About 20 degrees pitch was most that I could pull off. You might be able to go to 30 degrees with light load but I didn't try that. When you start quick stop maneuver lower the collective about half way down and make a hard turn left or right. Control rotor RPM and altitude with bank angle and G-load. Don't try to make the initial turn too hard but gradually pull the aircraft in the turn. Altitude control is particularly hard with this maneuver as when you are sideways you can't control vertical speed with collective and it reacts only slowly to changes in bank angle. Therefore it's better to climb a little than to try to stay very low. If you really need to stay low you should make a more shallow (less bank angle) turn with lots of sideslip instead so you can control altitude also with collective. Rotor RPM will rise at the beginning of the turn(or engine RPM drop, depending on collective setting) but at some point when you slow down it will start to drop. After it starts rising again pull collective gradually as much as engines can handle. Don't look at the RPM needles but listen to the sound of the engines and rotor instead. Pulling collective will provide extra muscle to stop the aircraft and keep up the engine RPM for hovering after you have stopped. After your speed has dropped below 100km/h you should straighten the chopper and flare to a hover. Basic mistake is lowering the collective all the way down when starting the turn and autorotating the rotor which just makes the deceleration slower and puts you into the "engines at idle" trap. Also if you don't lower the collective enough the rotors will clash when you start the turn. Other mistake is to make the initial turn too hard which leads very likely to either significant climb or crash as you have trouble controlling the altitude. One other mistake is to keep turning hard too long and entering VRS. The flare stop is already described in my previous post, just change the 30 degrees to 20. The basic mistake is to flare too hard and get in to the "engines at idle" trap. Examples of the maneuvers:

The quickest way to stop is to make a hard break turn to reduce speed to about 100km/h and then stop using basic flare (flare = decelerate by pulling nose up). Easier method is to just make a straight flare but it will take a little bit more time and distance but it will be lot more safer and easier to do. I'll try to make a video of both maneuvers with Ka-50 today but here's a link to real life quick stop maneuver with NH90. You can do this much quicker with Ka-50 and in simulator but the basics of the maneuver are the same. First make a tight turn to kill most of the speed and then stop using flare. The reason why you don't turn all the way until you stop is that you will enter VRS at the end part of the turn when your speed gets slow enough. As long as your pitch is less than 30 degrees and wings level when entering VRS zone you are going to be safe. Flare stop is done first by lowering collective slowly enough that you can control altitude with pitch. When your pitch reaches 30 degrees you keep it there and start controlling altitude with collective gradually increasing it until you have stopped. Deceleration will be slow at first but when pitch angle reaches 30 your speed is dropping very rapidly. If you can't keep up with the collective you might want to use shallower angle at first to make the deceleration slower.

So how you keep the shut down aircraft from crashing to the ground?

In Steel Beasts AI fires ATGMs usually from flank or rear to ensure penetration and making it harder for the target tank crew to notice that there's a missile coming at them. They will just sit and wait until you give them an opportunity for a kill shot or you start shooting at them. Clever buggers. These things are deadly if you know how to use them. They are not as powerful or flexible as tank main guns or fire-and-forget missiles but they still give a lot of cheap firepower for lighter vehicles.

Started digging through Raytheon site and found this: http://youtu.be/PhrgH_u24dc Distributed aperture system for helicopters in development.

You could build a practice mission with you and 3 wingmen against two enemy Hinds and practice taking them out. After you can do it consistently try the mission again. This mission isn't the only one where you are facing enemy choppers so air to air skills are good to have in general.

Helicopters fly either with side slip or slight bank at speed. Some helicopters might have taken some measures like mast tilting to eliminate this at certain speed (which varies depending on weight, altitude, etc.) but it still happens at other speeds to some extent. In single rotor choppers this is because of main rotor torque that needs to be compensated someway. In forward flight the vertical stabilator produces lift that takes over some of the load of the tailrotor but you still need a force pushing the tailboom to cancel the main rotor torque. This sideways force pushes the chopper sideways besides providing counter torque to the main rotor. If you want to eliminate the sideslip you need to fly with some bank angle. In co-axial Ka-50 it's a bit different. You can see from external view that the upper rotor is banked to the right and lower to the left and the bank angle of the lower rotor is much more than for the upper one. Rotor lift vector is orthogonal to the tip path plane which means that the sideways force of the lower rotor is stronger and hence the Ka-50 wants to sideslip to the left at forward flight. The reason why lower disk tilts more than the upper one is complicated as it's because of induced flow.

Can you elaborate as I can't understand what they are saying?

Helicopter air-to-air is all about pointing your weapons (ie. nose in most cases) to the enemy and blasting him out of the sky before he does the same. The exceptions is if you can see him first and there's good chances you can sneak on his six then you should "back stab" him. In long range missile combat the winner is who shoots first (of course you need to be in range). The slower one has no other chance but to defend or run. Vikhr can't follow targets which orthogonal speed is more than about 200km/h so they can be dodged easily by beaming the launching aircraft and speeding up. The problem is of course that while defending you can't guide your own missiles so the attacker can keep shooting and forcing the target to defend until he's in guns range. There's theoretical chance of turning the tables while the laser is still in guidance mode after firing and preventing additional launches. At that time window of 6-10s the defender can turn at the attacker, lock him and fire his missiles but that depends on the skill of the pilot to do all that in the time frame. The attacker can also reset his weapons system and re-lock the defender to reduce the down time of the laser. As has been noted it's hard to lock fast moving targets with Shkval unless they fly directly at or away from you. If you see an enemy Ka-50 coming at you from either side, ie. it's apparent he's attacking you, it's not smart to turn at him or away if you are already within missile range as you will just make yourself easy to lock with Shkval. After you have been locked you can break it only by breaking LOS by flying behind a hill or something like that. Even if he doesn't fire missiles at you he will get deadly accurate computer calculated gun solution on you which will be the end for you in most cases. Better way is to keep beaming him and when he's close enough dive and fly under him at high speed to keep yourself as a moving target to prevent Shkval lock. After you get past his 3/9 line you should climb and turn your nose to the enemy and blast him down as quickly as possible. This is not a fool proof tactic as skilled pilot will most likely lock you regardless of your speed but it's something to try when there's no better plan. If you can aim weapons with HMS it will give you tremendous advantage against enemies who can't do that. I can aim with HMS pretty good and so far no one (human player) has even got a shot of at me before I have shot down my opponent in unhandicapped fight. Many of them had their nose pointed at me but they still didn't manage to get a shot off. You can defend against attacking helicopter by flying under or over him but this is applicable only when you are already in very close. After that the winner is the one who gets the nose turned on the enemy first. You can turn the nose of the helicopter quickest by having some forward speed but no too much (around 70-150km/h) and the chopper turns like a biplane. High speed is the most slowest state for turn rate and hover the second slowest. If you are flying fast the most effective turn method for large turn (more than 90 degrees) is to pull up to a 30-60 degree climb to slow down and build an altitude advantage and then make a break turn. Here's more stuff about air-to-air procedures and demonstration about the HMS aiming effectiveness. http://forums.eagle.ru/showthread.php?t=92722

Shouldn't the more modern flak gun computer calculate TOF to target and then lead the target and set the fuze timing accordingly ie. the shell will explode somewhere in a cylindrical volume at the lead point after TOF. TOF is a function of lateral range and altitude difference. You could probably build a table with some simulated values and then interpolate between those to get about right TOF. Then you get the position and velocity vector of the target and calculate an estimate for the target position (which is the aimpoint) after TOF. Then you schedule an explosion to happen in a volume which size is dependent of TOF and which is placed at the aimpoint. This way you should have a pretty realistic flak simulation. If you want to simulate proximity fuses then you make the explosions happen at the current altitude of the target at explosion time but still within the aimpoint zone. I'm pretty sure all of this should be possible with SSE.

Material costs of modern high-tech products are pretty negligible compared to work related costs ie. man hours are the main thing you are paying for. Manhours in turn are pretty much related to how exotic materials (takes lots of work to extract, refine and turn in to usable form) are used and how complex the product is to design, manufacture and assemble. This also explains why it's cost effective to build multi billion factories with lots of robots to reduce the amount of workers (like in case of modern CPUs). Helicopters are complex machines built of exotic materials but you can't sell enough of them to justify highly automated multi billion factory.

This is what got me into orbit. It's a bit old and I don't know if there's more recent and better tutorials. http://www.aovi93.dsl.pipex.com/play_in_space.htm

It seems to me the old overcast cloud is a rectangular sheet that's not large enough for the rendering distance of the new engine. You can see it getting cut prematurely also over ground on the right. With the old engine ground rendering stopped at the same distance as the cloud sheet so it seems we might be getting much more view distance in addition of better visual effects.

Glad to know you are making progress. It's not enough to get the choppers speed under 10km/h but you need to also trim it for that state or the autopilots authority won't be enough to keep the chopper in hover. If the chopper is trimmed for forward flight it will try to push nose down in hover. You also must have FD disengaged for the autohover to work. The trick about hovering is to know the neutral attitude where the chopper won't accelerate in any direction and understand that tilting the chopper causes acceleration in the direction of the tilt. If you engage autohover successfully it will bring the chopper to the current neutral state. Ka-50 is in neutral state at hover with nose up about 5(+-2) degrees and pylons level. The actual required pitch and roll for neutral state depend on your loadout as fuel and weapons will change the CG. If there's wind you naturally need to lean to the wind a bit. When the chopper is in neutral state it will stay put or keep going to the direction it was going. For example if you need to slide right you don't keep the chopper tilted right all the time but you tilt right for maybe one second and then level it and the chopper will keep going slowly and steadily to the right until you make similar tilt to the left that will "neutralize" the velocity component to the right and stop the chopper. These kind of small and short tilts will be enough for precise maneuvering but if you need to move faster than about 15km/h you will start to keep the chopper tilted to overcome drag. You can make hovering flight very easy for yourself by trimming the chopper for hover and disengaging FD. Now the chopper will automatically always return to the neural state when you let go of the stick so now the cyclic controls your lateral acceleration instead of pitch and roll.

Your flying looked pretty much the same as last time except it was even more random looking this time and you pitched nose up soon after taking off and crashed the chopper tail first to ground and exploded in a glorious fireball. I'm pretty sure both of your tracks were more or less broken. Have you checked them yourself before uploading that they actually show what really happened and you have the latest version of DCS World? Best way to learn hovering is practicing hover landings. Take off from FARP, fly a little circle so as to pick up some speed (about 100km/h should be enough) and then land. Try to land exactly at the center of the FARP pad (rotor hub is smack in the middle when viewed from above). Repeat this for 10-20 times and then do it again next day. Keep doing this routine about twice a week until it feels too easy. Then do it again after a week or two. Descent is easy as long as you don't do it while hovering. You should keep at least about 70-100km/h forward speed while descending fast to avoid VRS. Don't try to land like the AI does by stopping above the pad at 15m and then slowly hovering down to the pad. You can't see down at all and you could very easily drift over other pad and hit other choppers when coming down. Even if you are careful it takes lots of time and extra effort to land this way. Better way is to come down in 10-30 degree slope 30-10km/h so that you fly towards the landing spot and see where you are going. Gradually slow down the forward and descent speed while coming closer to ground. The following link shows the idea of an easy landing style.