Tim_Fragmagnet

So what's currently happening is that low speeds and hovering take far too much power, thus an unrealistically large amount of left pedal. As you speed up into translational flight, you require less and less power, thus less and less left pedal, that is correct. However it is overly exaggerated in the new model. Something to note is that the tail rotor has always been messed up in this module. As seen here, It's hard to quantify if this is an improvement or not, in some ways yes, it is better, however in others it is significantly worse. As for if it's supposed to feel this powerful. If you check the charts, we're actually still lacking power at the high end. It's supposed to be even more powerful than this. In terms of keeping the nose down at high power settings and low weights, it's possible that the real aircraft had this issue as well, but it is difficult to find data on this, as the Vne for the huey was 125knots as a safety precaution to keep pilots from accelerating into retreating blade stall, so recorded performance data generally ends there. Another limit is the transmission limit of 50PSI of torque, it can operate above that limit at risk of damage, but once again, finding recorded performance data at that range is very rare.

@P61 Let's reconvene shall we. The fuel consumption is unacceptable. The achievable true airspeeds at different altitudes are way too high, and are unacceptable. The power requirement for hovering is unacceptable. At high power settings we still underperform fairly significantly. It is better than it was before, but 6500lbs performing like 8500lbs while within the officially stated Vne is still not acceptable.

I have Run 3 tests, one at 50PSI, one at 40PSI, one at 30PSI, each with 1000lbs of fuel the results of those tests have been overlaid onto the fuel consumption chart for our exact model of huey, retrofits and all. Here are the tracks 30PSI 1000lbs fuel 50 minutes.trk 40PSI 1000lbs fuel 41 minutes 50 seconds.trk 50PSI 1000lbs fuel 36 minutes.trk This information has been compiled in the main performance charting thread as well.

The new performance profile has exaggerated the power requirements in translational flight. The huey now requires far too much power at low speeds, and far too little power at 60knots, this causes a massive torque change as you gain speed. the graph visualizing this can be found in this thread

It needs another rework. For the points marked as "level flight impossible", I am unsure if it is realistic or not, it is very possible the real aircraft produced enough power that full forward cyclic could not maintain level flight. However data for flight over the Vne of 125knots, let alone over 50PSI is hard to come by, and usually for the UH-1H with the old blades. Overall the huey has more available power, however at low speeds the performance discrepancy is not good. You go from requiring far too much power to requiring far too little power. However, the engine profile doesn't seem to take altitude into account. As for the engine profile itself, it is still underpowered at high power settings. The new profile produces 50PSI (1158shp) at 101% N1 The real huey produces 50PSI (1158shp) at 96-98% N1 However the EGT profile has improved significantly. The hover performance is not great, however. It requires too much power at every weight. Here is a more advanced profiling of the hover performance. The new WIP fuel consumption is far better than it was, but it's still using too much fuel at higher power settings, however it is reaching what could be considered "close enough", but could still use another tweak. The rate of climb is messed up too.

Further research has found that the tail rotor on the DCS huey rotates too fast. At 324rpm on the main rotor, the real huey's tail rotor should have an RPM of 1,655.070084 More specifically the real version of our huey has a tail rotor to main rotor gear ratio of 5.108241:1 The DCS huey by the same metric has a gear ratio of 5.5:1 A tail rotor RPM of 1,782 at 324rpm on the main rotor. You can test this yourself by watching the huey's rotors at a low RPM from an external view From page 41 of this document, a performance profiling of our exact variant of huey. null

One more just to make sure it's well and truly settled that it's supposed to be this way.

Here's some interesting data From We find info on the gas producer speeds for a huey with the standard blades. Ground Idle/start speed 48-52% on the gas producer gauge. We can test that in game. \ 57% Nearly 10% too high, interesting. One would assume the new rotor blades wouldn't increase idle power requirement by that much. I'll have to do some digging to try and find out what's going on with that.

Our performance high up as it is, is already too high. In fact, we GAIN performance as we gain altitude up to about 8000ft density altitude right now, which is not what is supposed to happen. Anything over 5000ft density altitude sees our huey currently performing over spec. If it were realistic we would have worse performance higher up than we currently do. Also saying "we'll load more stuff into it and be power limited again" Load WHAT into it. We are underperforming by an amount equal to what our useful load should be. Our huey at 6500lbs is currently performing like its at 9500lbs. So if you load our current huey to 9000lbs, it's basically performing like it's at 12000lbs Fix the power issue, and it would then correctly perform like it's at 9000lbs, what else are you going to throw into the helicopter that will add another 3000lbs that would cause it to perform like it previously did. What are you going to load full fuel, all the miniguns, the rocket pods, 2400lbs of troops AND a slingload onto it? You being power limited at that point is YOUR fault. And it's not "getting more power" it's "using the correct amount of power" We are currently using TOO MUCH power, that's the problem. Which INCIDENTALLY, also means we are generating too much torque. If the power usage gets fixed, we will be generating less torque, which will mean an increase in stability. If this gets fixed, the huey will be more stable and shake less, because currently, with our overdraw of power and thus overproduction of torque, we have to jam the pedals to the left to combat the torque which causes axial instability from the tail rotor. Lower the torque, lower the required amount of left pedal, lower the axial instability, lessen the shakes, gyrations, and wobbles.

If it didn't matter, they wouldn't have kept doing it for all this time.

The synchronized elevators on our huey are symmetrical. They aren't supposed to be. I believe this image shows it off well enough You think it's just an artifact of the old photo? here's a newer photo You want documented proof of it? Page 56 Why has this never come up before even from people who look through data? Because the data usually only ever references the right elevator alone. I don't know why.

here's a photo of the huey's tail rotor blades pitched in the nose right direction. With the knowledge that our huey has been producing far too much torque due to needing too much power, this issue will hopefully gets fixed alongside that one, otherwise our pedals are going to be in very strange positions in flight.

OK this subject is fun. FIRST OFF AS IMPLEMENTED our XM60 sight has the 50mil DIAMETER reticle HOWEVER A 50mil RADIUS reticle ALSO exists As does an 80mil DIAMETER reticle. all for the same sight. 3 Different reticles 1 sight Wild, right? Regardless. AS IMPLEMENTED Our sight is the 50 mil DIAMETER sight. As implemented, it IS correctly scaled. A 50m wide object at 1000m will fill the diameter of the 50mil diameter sight. Here is the proof, the C-17 has a wingspan of 53m There is nothing wrong with the reticle itself. The problem lies within the elevation knob. This thing. This knob is measured in mils. So if you increase or decrease it by 50 mils, the 50mil diameter sight should move so that the top is now where the bottom was, or vice versa The reticle should move by 50 mils if you change the knob by 50 mils, simple. HOWEVER. As you can see, to shift our 50mil diameter reticle by 50mils, we have to change the elevation by 95 mils. This is obviously incorrect. This isn't a matter of just changing the scale of the reticle either, as that doesn't fix the issue. The issue is that 5mils of elevation on the knob, does not equate to 5mils of rotation in the reflector sight. Changing the scale of the reticle won't fix that. This matters because the elevation table on the sight itself, this thing Asks you to adjust the elevation by mils. This means adjusting the elevation by 20 mils does not actually adjust the elevation by 20 mils, meaning your sight zeroing is incorrect for your chosen parameters. This needs a fix, either changing the scale depicted on the knob itself, or by changing the amount of elevation displacement so that it matches up to the number of mils on the elevation knob. I do not know which would be the correct option that would make it more like the real thing, however either option fixes the issue.

Read the post again I directly mention that, yes, the airspeed indicator is SUPPOSED to be inaccurate at low speeds. However the way ours is implemented isn't inaccurate in the same way that the real one is. Something that we have explicit documented data for. Our indicator starts reading at about 25knots true airspeed and reads 12knots indicated at about 30 knots true The real indicator starts reading at about 15knots true airspeed and reads 20 knots indicated at about 30 knots true.

I'm going to start this with yes I know the airspeed indicator isn't supposed to indicate speed perfectly. There is a degree of error at different speeds. This is about the module's airspeed indicator not properly following the error the real aircraft has. I'm going to preface with this, yes, it's a discrepancy of 8 knots, normally it wouldn't be THAT bad. The problem is that this error is at a true airspeed under 40 knots. While you're trying to land. Where accurate speed monitoring is important. Here is a profiling of 30-130knots true airspeed. You'll notice at speeds above 40 it's pretty much perfect, completely acceptable. I have ZERO issues with the calibration above 40knots. But you can see what's happening below 40. Here are some profilings of 50-30knots true airspeed You can see that there is a very clear pattern of error in our airspeed indicator that the real thing does not follow. This is part of why it hangs under 20 for so long. Another part of why is because the indicator doesn't really start moving until you hit about 25knots TAS. Documented data points toward this likely being inaccurate and 15knots TAS at 0 indicated likely being correct instead. Here is a chart comparing the current calibration vs the real one Here is that same chart but with what I suggest as a more reasonable adjustment This isn't really a critical issue like the performance model or the tail rotor being wrong, but it is an error that could be corrected. The expected IAS reading data were taken from the huey's flight manual. And the charts were taken from the composite blade performance profiling document

So, I was asked to provide track files, that seems to no longer be a requirement However, I had still made them, if you wish for me to provide them, simply ask. However, the flights did allow me to produce more information. I flew the huey at 6,500lbs, 7,500lbs, 8,500lbs, and 9,500lbs, each at speeds lining up with specific points on the torque performance chart in the manual, these were flown at TRUE airspeed, facilitated by the use of the true airspeed display in the F2 infobar. So there is no error in the data collection due to IAS inaccuracies. I then compiled the information onto a chart alongside the real huey's torque performance. here is that chart. The expected torque values have been corrected by the 2sqft drag factor of the IR suppressor. As you can see, we are underperforming by a fairly significant margin at higher speeds, and the loss in performance forms a very clear trend as you can see by the delta data at the bottom. However that is not the full set of data This is. Now, you're likely wondering what those extra bits of data are at the top end of the graph. Those are plots of the real huey with standard blades being pushed past its transmission limit, all the way to the maximum output of the engine, 1340shp. However you will notice that if you try to line them up with the real composite blade huey data, they don't form a smooth set of data. That is because the composite blades have higher performance than the standard blades due to being lighter. So, if you spare a little bit of your imagination, just for a moment. This is what I propose I didn't really know exactly what to do here, I could have just shifted the standard blade plots to the right until they formed a smooth plot of data, but that would put the huey at somewhere near 160knots at 6500lbs if you push the engine all the way. Instead, I opted for an assumption, while the new blades are higher performance, they're also lighter, meaning drag on the rotor is more of a factor, meaning a higher blade pitch likely produces more torque than a heavier rotor, coming out to what is actually a reduction in max power performance but an improvement in the performance at the transmission limit. Now, I'm sure there's some math in the composite blade documents that could let us just compute the real performance of the composite blade huey at that level of power output. However, I do not have the intelligence to do it. I believe this would be the math. null As for where that standard blade huey data comes from. once again, our friend from the original post On page 95 we have a velocity limits table As a reminder, the transmission limit is not the absolute limit of the aircraft, it can push harder to achieve max power performance, you are just risking damage to the transmission. All of these speeds are in true airspeed in knots. As a reminder, that table is for the STANDARD blades, NOT the composite ones. the data shown there is theoretically lower than it would be for the composite blades, however I do not believe that I have found similar data for the composite bladed huey, so we can only guess as far as I know.

With the new knowledge of our torque being too high for any specific speed, you may want to look into this thread as well.

I'm running the slick huey with the IR suppressor and to get 9500lbs you can use an internal cargo trigger to add weight to the aircraft. At full fuel (7438lbs), 935kg should get you to around 9500lbs That configuration at 6100lbs would be somewhere just under an extra 2psi, the drag curve doesn't extend that high up so you have to eyeball it. at 9500 it would be +1.2psi \ Even with the corrected torque value our huey at 6100lbs is performing how it should be at 9500lbs. We are underperforming by 3400lbs Something is wrong, power we should be getting just isn't there.

Alright how about one more test this time we'll cross reference 2 different datapoints We'll run the huey at the same parameters as usual, at 9500lbs, and we will normalize to about 33psi, as per the chart, this should get us about 110knots It doesn't. OK now lets cross reference something Lets run the huey at 6100lbs, and normalize to about 33psi, this should blast past 110knots and should even pass the Vne Except we don't. Our huey, at 6100lbs, at 33psi, can't even reach the speed it should get at 9500lbs at 33psi Do you see what's happening now? Where is the power output? We are underperforming by over 3400lbs. How does the our DCS huey at 6100lbs 33psi, perform how the real huey should at 9500lbs 30psi. A heavier weight, at a lower power output.

and I believe I have found the sticking point I'll ask you again, try it at 9500lbs. While speed is part of the problem, the main problem is the total engine output. The problem is lift capacity. As modeled, our engine pushes the torque to 50psi at 100% N1, meaning at max output, our engine is only putting out 1158shp. That's the problem, because it's SUPPOSED to be able to push 1340shp, pushing the torque all the way up to 58psi. As modeled, our huey is performing like it's 3400lbs heavier. Also If I do the 9500lbs cruise test but instead normalize to the proper PSI for 100knots

I'm not talking about true airspeed for the inner scale I'm talking about the roof pitot scale You're flying too slow in your tests. your indicator should in fact actually read 100 if not 101 knots IAS at sea level for a TAS of 100knots. The pitot was moved to the roof because it was more accurate than the nose pitot. Our module has the roof pitot. This thing Also if I do the 7500lbs cruise at sea level 15C at the correct IAS 0 We get 34psi

First, you're referencing an outdated version of the huey's manual, yours only has changes 1-18, afaik 1-20 is the most recent, granted I've only found one with 1-19. Second, I didn't use the operating speeds chart as a reference, I refuted it as a viable reference for the reasons you stated. It tells you the fastest you're ALLOWED to go, but not the fastest the machine can physically push itself. It cannot be used as a reference for the actual performance of the machine. Third, you're measuring against the nose pitot IAS, our huey has the pitot on the roof, so the inner scale is the correct one, not the outer one. So it should actually read 100knots at sea level, if not 101. Fourth, add more weight, at 9500lbs in a 100knot sea level 15C cruise, as per YOUR chart, you should be at about 29psi You won't be Fifth, "The shaft horespower equation, which good for approximating things, doesn't take into account all the various other factors that effect performance of the aircraft, so i'd be careful in it's use. It can definitely get you in the ballpark, but it's typically off by a fair amount." If the aviation engineers figuring this out by hand so that they can properly profile the load placed on the drive system say it's good enough. It's good enough.

To put the TLDR first, our huey is underperforming by 3400lbs while being provided a lower available power than the real thing, and made slower than it's actually supposed to be at low altitude (which is where it normally operates) So what are my sources? Before that, lets start with a very simple summary of HOW WRONG the module's performance actually is. null Now, I won't act like that's the whole story with all the context, because it's definitely not. There are things like the transmission limit to take into account. But those sources, lets see them. Here are the 3 main sources, there are several other minor sources as well, however the majority of the data comes from these 3 documents. null So allow me to clarify something, our huey is one with a 1990s refit, it is the one with composite blades. You may have noticed, one of those sources explicitly mentions the composite blades in the title. That source is a performance profiling of our exact model of huey. Refits and all. Now, there's something else to talk about, the huey's operations manual. You might be familiar with this chart. This chart is useless. This chart doesn't tell us where the transmission limit is, it doesn't tell us how much engine power is being used to generate those speeds, it doesn't tell us ANYTHING. That chart is a significant misrepresentation of the huey's performance capabilities, because all that chart shows is a paper limit on the huey's speed. Vne, Velocity, never exceed. A scary term, used to define a speed you are to not exceed for assorted reasons. For the huey, the Vne is in place to keep the pilots from accelerating into retreating blade stall, nothing more. It's a paper limit to keep the pilots safe, it tells us NOTHING about how the aircraft performs. However, if you look at the bottom of that chart, "Data basis AEFA Project No. 84-33" Go back and look at top of the source that mentions the composite blades, that is AEFA Project No. 84-33. The data from that document was used to generate that chart in the manual. So before we go farther, how do we corroborate all our sources to make sure they're on the same page and providing us valid information. Cross checking. Take one set of data, and see if the patterns within it match the patterns in another set of data. We can do that. Here is the overall performance of a huey with the standard blades at 7,500lbs, derived from the data within the UH-1H flight profile performance handbook. Pay attention to the density altitude of 7500ft, you see where the yellow and red (transmission limit and power limit) lines intersect, that is where the engine can no longer provide enough power to max out the transmission. Now here is the hover performance chart from the composite blade document. Look at the rightmost line. "2ft IGE, standard day". You might have already noticed it. Incase you didn't. So our documents are in agreement, what do we do with this information? We start comparing it to the performance of our huey in DCS. Lets start with a more complete performance profiling of the real huey with the standard blades, once again, this data is derived from the UH-1H flight profile performance handbook. This data is for a huey with non composite blades. So there are multiple plots here, let me walk you through them. The first one that likely sticks out is the blue line since it's away from all the others, that is the Vne. The fact that it is placed lower than all the other data reminds us of the chart in the manual. I said that chart was useless, because as you can see by this graph, every single other plot of data performs significantly over what the Vne would have you believe. The next two that likely stick out are the red and teal lines. These are the performance of the DCS huey plotted onto the same graph, the red line abides by the incorrect EGT limit placed upon the module, the teal line ignores said limit and properly maxes out the transmission where it can. Next would be the green and yellow lines, the green line shows the maximum power the engine can normally push, regardless of any other factor, at sea level that would be 1340shp. The yellow line shows the maximum CONTINUOUS power the engine can push. This means the engine can run at this power setting indefinitely without much issue. And finally, the orange line, this line shows the safe limit of the transmission, specifically, 1158shp, or 50psi on the torque indicator. This is the huey's military thrust it can use this power for 30 minutes. This is not the LIMIT of the aircraft's performance, the transmission CAN PUSH HARDER, it just does so at the risk of being damaged. Yes, this means that, per this data, the huey should be able to reach 141knots in level flight. Something you'll notice, the teal line, our huey's performance, can't even reach the transmission limit at sea level. While, conversely, our huey's performance actually PASSES the real huey's maximum possible performance at higher altitudes. So, from this alone, you can see that the module's performance accuracy is not great. But that's not the whole story, that's just for the standard huey, and we haven't even gotten into engine performance per speed yet. We'll do that now. Here is a chart from the composite blade document, it shows the level flight performance in speed compared to the shaft horsepower generated by the engine to achieve said speed at a gross weight of 9500lbs at sea level in 15C temperature air, ISA conditions. On it, you will see a pink data plot. That is our huey measured by the same metric. 9500lbs, Sea level, 15C air temperature, ISA conditions. You'll notice that our huey isn't even performing as well as the huey with the standard blades, let alone the one with the composite blades. But first, how did I get the horsepwer data from the DCS huey, we don't have access to that data. Except we do. We are given the torquemeter, which when combined with the rotor RPM, we can derive the current SHP put out by the engine. As per our previously unreferenced source "Helicopter drive system load analysis". Pages 43-44 detail a formula to do exactly that, derive shaft horsepower from our torquemeter reading, and rotor RPM. Here is that formula. SHP=3.88*((10^-3*Rotor RPM)*((17.76*Torquemeter Torque)+33.33)) Now, you'll notice that graph shows the composite blades as being measured with the rotor at 314rpm, that's ok the difference in the result isn't exceptional, however here is a table showing the same data and including 324rpm on the composite blades. So, 639shp to push the helicopter to 100knots at sea level at 15C at a gross weight of 9500lbs. That would be 26.745psi on the torque indicator in the cockpit. As you can see by the pink line on the graph, however, we didn't even get close. We hit 36, possibly 37psi on the torque indicator at those parameters. Level flight, 9500lbs, sea level, 15C, 100knots. 36psi at 324rotor rpm, as per the formula, is about 845shp, over 200shp too high. Now, we can use this formula to find something dire. Lets make the huey as light as we can and see how it performs. 6100lbs, all it has is about 9 minutes of fuel Sea level 15C 100knots level flight about 30.5psi in those parameters. 722.8shp at 100knots. The real huey pulls 639shp in those parameters at 9500lbs. Our huey, at 6100lbs, is performing WORSE than the real huey at 9500lbs. Our huey is underperforming by over 3400lbs at low altitude. That is unacceptable. Interestingly, these high torque values also explain why we need an unrealistic amount of left pedal, which when combined with the incorrectly modeled tail rotor, brings about some interesting comparisons. So, now that we have the well documented performance profile from the standard blade huey, honestly, we could just use that one for our huey and it would be fine, the overall speed differences shouldn't be drastic, it'd be far more accurate than what we have now. As for why our huey overperforms so much at high altitude, I don't know. All my efforts were aimed at understanding its performance at low altitude as that's generally where players utilize the aircraft. I suspect it may be a combination of the engine not losing enough power at altitude and rotor mach drag not being modeled. However, for now, I believe this should be sufficient to warrant the developers looking at it. Please. Properly implemented, our torque indicator should actually max out at around 58.15psi while the N1% (gas producer) gauge reads 100% As it stands, we are using too much power, to generate too little speed, at too high of an EGT, causing us to have even less power. We are underperforming by over 3400lbs at sea level, it needs to change.

Further research has produced an answer. Performance data of the YUH-1H, the pre-production model of the UH-1H, the one every future UH-1H would be based off of. Page 44 1340shp Whether that means 1340shp at 100% N1 or 101.8% N1 (the limit of the engine) Well page 205 has the answer to that question. At least for the early UH-1Hs 100% N1 is 1340shp. I will update the OP with this information.

So you think we have a UH-1H from the 70s even though I've proven that we don't, and you think that would make a difference? Well fine Here is the flight test data of the YUH-1H from 1970, the literal pre production UH-1H, the one every single UH-1H would be based off of. Here is page 224 full left 19 degrees to full right 7 degrees in the other direction From the START, the UH-1H has had the tail rotor blades able to pitch inverted to push the nose to the right faster. Because if it COULDN'T, then it wouldn't be able to properly trim in certain flight profiles. It's not an opinion, it's not some crazy made up scheme. It's a fact with raw data to back it up. The tail rotor on the DCS UH-1H is implemented wrong.