just lets say my most expressed complaint is about ...
"flaps in general, and how they effect the envelopes of the plane set" for simplicity.
i am just having trouble equating the situation in AH and some other games with the expert conclusions such as the one in this report
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930092640_1993092640.pdf
which seems to limit the benefit of combat flaps more so than what the game represents.
Hi Thorsim
It may seem that way, but if you had the ability to produce the kind of diagrams used in that report for the Aces High aircraft, and compare them with those for real aircraft, you would then see that the report you posted provides strong and convincing support for the behavior of the Aces High aircraft.
However, I suspect you may not be able to do that, but fortunately I can. I've been applying those methods to flight sim's since Air Warrior back in 1989. I can also produce EM diagrams of real aircraft for comparison, and where diagrams already exist for real aircraft it is also possible to compare them directly with an overlay.
When I do this, I can use either the modern format EM diagrams developed by Boyd in the 60s, or I can use the style of diagram used by the original inventor who developed them in England in the 30s that are very similar to those in the F2A-3 report you posted. However, one advantage to producing the EM diagrams seen in those early reports is that they can be compared with the ones that exist for the real aircraft.
For example, here is an overlay of the AH Spitfire MkI and the Me109E (that I did about 7 years ago now) using the modern format.
Now using the WWII format, the Spitfire in the previous example has this diagram:
But let's compare that with the diagram for the real Spitfire MkI.
Here we can see that both the real Spitfire and the AH Spitfire have the same corner velocity at that altitude and configuration, so let's compare a turn. Just for example I've selected a 5g turn at the corner speed of 250mph. I've indicated on the diagram for the real Spitfire that it would need to descend at 16 degrees below the horizon to sustain that turn and it would turn a full circle in about 14.5 seconds with a radius of about 850ft. You can see from the diagram for the AH Spitfire that it would also make the same turn in about 14.5 seconds with a radius of 850ft, and that it would need to descend at an angle of 23 degrees below the horizon, a descending turn only 6 degrees steeper than the real aircraft. But the turn rates and radii for the turn, along with the corner speed are amazingly close. The difference in the angle of descent is probably due to differences in engine power available at that altitude between the real world tests and Aces High, and perhaps some differences in weight. It is interesting that both diagrams are the same shape, and that they agree very closely in many respects, indicating that the flight model in Aces High has accounted for all of the aerodynamic factors that would influence the shape of the curves to any significant degree. A worthy achievement indeed. This is even more significant, because I've made a similar comparison with the Spitfire and 109E from other simulations, and so far Aces High has first place for accuracy.
That example doesn't include the use of flaps, however, I can just as easily produce the same analysis and corresponding diagrams for cases where flaps are employed, which brings us to the question of flaps...
Now what about the situation when flaps are employed?The problem here is that when you find either technical reports or anecdotal evidence on the merits of flap use, some seem to say say that prolonged use will harm turning performance and others will say that it won't, and the striking thing about those sources is that there is truth in both perspectives.
We can see why by looking at the diagram shown below:
For the split flap configuration illustrated in the diagram above, the benefit depends on how high the lift coefficient is. For example, at low values of lift coefficient use of flaps is not good, and you can see that the two points A and B in that diagram have exactly the same lift coefficient, but point B, has a higher corresponding drag coefficient. That explains why you shouldn't try to use flaps during maximum rate climbs, or power off glides, the drag penalty makes it prohibitive. That situation continues up to a relatively high lift coefficient where the two polars cross each other. The point where the polars cross is quite high, and that means that most turns at high G conducted at speeds close to corner velocity will suffer higher drag and lower sustained turning ability with flaps extended, which also explains why so much anecdotal evidence claims that using flaps is bad.
However, there is more, if you look at the diagram again, you notice that the drag is exactly the same at point C and D, but that the lift coefficient is much higher at D, meaning that once the crossover point is exceeded, you can get more lift for the same drag, making flap usage advantageous. In practice the region of the envelope where pilots can take advantage of this, occurs generally at much lower speeds, where high coefficient of lift values can be achieved at tolerable G levels and can result in better sustained turns.
The point is that both better and worse sustained turns are possible, it just depends on the particular conditions under which the turn is being executed, which basically means that so far everyone could be right. But most importantly, Aces High gets it right across the entire envelope.
While it isn't easy to find data for flight tests carried out using flaps, (of which the report you posted earlier for the F2A-3 is a rare example) it is much easier to obtain data such as the flap characteristic curves I posted earlier and use them to generate EM diagrams for the real aircraft that can then be compared/overlaid with the EM diagrams produced for the aircraft in Aces High. For the very limited number of comparisons I've made, the degree of correspondence with the Aces High flight model has been very impressive indeed. This may simply mean that HTC were able to find the same polar curves that I found, but either way, the correlation with real world data is there to a high degree of accuracy.... A significant achievement, once again, Kudos HTC.
Lastly, there is one other very good reason why it may be possible to find much anecdotal evidence against the use of flaps in combat, and why that may conflict with our experience in a simulation. The reason for this is due to something that is as true today as it was in WWII.... Speed is life. Getting slow in a hostile environment is the kiss of death. In real life nobody wants to die, so nobody wants to get slower than necessary. Those who did, probably didn't survive to talk about it.
In contrast to that, in our flight Sim's, nobody has to experience fear, and the slow fights are much more fun than high speed attacks, which are almost boring in comparison. In an environment where life and death are meaningless, we have the ability to explore the envelope in a way that may well be unrealistic in terms of the human instinct for survival, but is entirely realistic in the way the aircraft perform, both in Aces High and in the real world.
Hope that helps...
Badboy
