Aces High Bulletin Board
General Forums => Aces High General Discussion => Topic started by: Badboy on September 06, 2000, 04:27:00 PM
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I have just started work on an article that may have some bearing on recent threads regarding the fidelity of the Aces High flight model. Attracted to Aces High by what is clearly superior flight dynamics modeling, I began an analysis of the individual aircraft. It was soon apparent that while most of the aircraft match the real world numbers in some respects, there are significant discrepancies in others. That of course brings me in conflict with my normal policy when writing about almost any flight simulation, that is to highlight those points that are good, while ignoring those that aren't. That policy has always served me well, because I generally preach to the converted, and almost never write reviews! Not to mention that highlighting weaknesses in some ones favorite flight sim' almost never goes down well.
However, in this case I can make an exception for two very good reasons. Firstly and most importantly, I'm not going to be telling anyone anything they didn't already know, I'll merely be quantifying a few issues. Secondly, those issues are known and scheduled for remedial action, so to be fair, I can publish the article after the adjustments in the flight model data have been made and duly accounted for in my analysis. So what will the article be about?
In a nutshell, aircraft performance comparisons for dissimilar air combat, one of my favorite topics. During the coming months I intend to give some attention to the aircraft of Aces High and provide some comparisons of many of the more interesting match ups. However, I'm just a tad excited about my next article because I'm doing a couple of things I haven't done before. Normally, I restrict my comparisons to aircraft within the simulation, simply because that's what the folk who fly competitively within it need. Hard accurate information about how the performance of one aircraft compares with another, presented in the form of energy maneuverability diagram overlays. However, the new twist to this is that now I can also compare the simulated aircraft with their real world counterparts, and taking that to its logical conclusion, comparing one simulation with another.
So, to be more specific, my next article will compare four different P-51Ds, the real P-51D, and those from Aces High, Air Warrior, and MCFS. I'll include a description of the issues related to the data used to drive the flight models, along with any factors related to the models themselves, and an insight into some of the detective work involved in the analysis of the real world aircraft. But of course, all this, only after the next version of Aces High, with any flight model adjustments.
Meanwhile here is a taste of what lies ahead. Here is an EM diagram overlay for the real world P-51D, shown in blue, and the P-51D as currently modeled in Aces High, shown in red. Notice that the real P-51D could sustain a maximum of 3.5g, and could sustain its best turn at just a little over 3g giving 22.4 degrees per second (dps) and a 600ft turn radius. In comparison, the current Aces High P-51D has a best-sustained turn of 13.6dps at just over 2g and 1080ft radius, a significant disparity. It appears as though Top speeds are as close to the mark as we could hope for. However, the low Ps = 0 curve for the Aces High P-51 indicates poor energy retention in the turns and reduced sustained turning ability, with respect to its real world counterpart. That is why the article will remain in abeyance until after the next patch, and also of course, because I don't want to analyze too many of the Aces High aircraft while changes are imminent.
(http://www.netcomuk.co.uk/~badboy/PDF/AH_P-51D.gif)
That may all sound rather negative… On the contrary, Aces High has impressed me with its flight model, there appears to be some minor glitches in the data being used, but as those are corrected, as I understand they will be, what we have now is destined to evolve into the best online flight sim' available... I'm sure it is going to be a pleasure to write about it!!
Badboy
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Sounds fantastoc... can't wait to see the final effort!
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Can't wait
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Hot damn! I though your interest had waned or other things in life had grabbed ahold of you when I noticed your postingss about the FM and such had tapered off a couple of weeks ago. Nice to see I had no fear of that. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
I have to salute you Badboy for the way you write these up. I may not udnerstand all the fine details but your mastery in wording keeps me glued to the report(s).
I'd be remiss not to mention again how much I liked your works when I saw them in AW prior to several of the scenarios there that allowed partipipants to get a better feel for how the aircraft of both sides could possibly match up against each other.
And I chuckle now remembering sitting next to RM at the AW 1999 CON and tryin to track you down in the FT arena because he thought you had some kind of a cheat that allowed you to disappear when he was close on your "6" (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
I look forward to reading your analysis very much!
<S>
-Westy
[This message has been edited by Westy (edited 09-06-2000).]
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HOLY MOLY!
I'm more than impressed.. I'm awestruck! (and can't wait till the pony gets the sparkle back!)
Bless you, BB.. this article will be greatly anticipated.
Hang
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Y'all know that the flight model is gonna get a major reworkin' in 'bout two weeks. Might render yer nice analysis rather moot.
Badboy, ya might wanna consider waitin' 'till 1.04 is released 'fore ya start the research.
Sisu
-Karnak
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Badboy,
You tease. I have been waiting to see your work for sometime now. Any chance of getting a sneak peak of the F4U??
Anyway I have been laying off any further anaysis or critic of the AH FM until the next patch myself. I don't think it redefine ACM in the MA. But I do think it will help to enhance the difference between A/C flight envelopes and help to further define A/C characteristics. In other words make it harder for a P-47 to out turn a Mustang. And make it harder for a Mustang to sissor with a Zeke without overshooting.
Waiting anxiously
F4UDOA
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Badboy,
Normally, this kind of comparison and flight data stuff bores the ever-living sheet out of me, as I just like to fly and am happy to leave the numbers to Pyro and HT. However, your post has me quite interested, particularly in the RL to game to game to game comparisons. Thanks! I look forward to your articles (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
SOB
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Where on earth did you get an EM diagram for a real P-51? Is that based on analysis or flight test data?
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Are you going to test the P51 for MSCFS1 or MSCFS2? cos the CFS1 a/c is way off, its about 2000lbs too light for starters, I have been through this in the past with CFS.
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Oberstleutnant LJK_KämpferAs
Kommandeur von II Gruppe
ExecutivOffizier von LuftJägerKorps
www.LuftJagerKorps.com
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Hiya Badboy! <S>
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Very interesting stuff Badboy. It will be insight(or cite for some)ful how our new changes will compare to the current model. Your findings appear to be very similar to ours. I look forward to seeing your tests on our next version as well as other games.
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Doug "Pyro" Balmos
HiTech Creations
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Does this quantify my doghouse observations about the 1.03 AH P-51D having anemic energy retention?
Yeager
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Damn .... this sounds interesting as hell. Can't wait for the articles to begin.
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Nice info!
Would you mind doing the P-38 next? I got a certain.. umm.. personal interest in it here (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
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What pony Sparkle BAck man huh sik about this pony wing not go off even after 4 x 20 mm below 400 and some ! crying for sparkle back , beter Try the 190A8 is it a real chalange surive in that plane contra any plane when pilot is just average !!!!!!!
so what we can say about A 8 ? aaa is it jsut for pony practice ? t ostrafe it ?
well I dont like this WAY
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Oh my gawd...Badz!
Can't wait for these articles but tell me, am I gonna have to suffer innumerable deaths from you here like I did in AW?
(http://bbs.hitechcreations.com/smf/Smileys/default/rolleyes.gif) <--lookin' up for Badz
Lars
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How about posting various diagrams for all AH planes ? Could HTC publish their own data ?
Would be nice to see H-M or EM diagrams for both Fw 190A-8 and P 51D so we can compare things.
HTC ?
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Stoickov
JG54 "Grünherz"
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Jeeze.. you ravening dogs.. BB made it clear he will hold up further AH plane testing till after the new release.. in the meantime he's doing evals on the other sims AC FM's.
Yeager.. YES!.. further, this also indicates that my own laments about the loss of energy retention and sustained corner performance I saw on the P51 when our CURRENT flight model was 'adjusted' back in beta was also justified.
Not that it matters one bit... it's still been and still is fun ta fly, and what we have NOW is still the best rendition I've ever seen in a sim; and as has been pointed out.. the journey is not over. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) In other words, what we have is pretty damn good, and what were gonna get is gonna be even better.
Kudos, Pyro, and HTC.. and the rest of yah, climb off BB's back.. his eval's and comparisons are ALSO a work in progress, and none of us have invested the time and effort in this he has.. let him do his thing without harrasment from the peanut gallery... lets encourage him to keep us informed of his progress rather than give him a reason to clam up.
!
Hang
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Hi Badboy,
I like very much your AirWarrior EM diagrams. But, isnt a waste of time to analize CFS's Pony? Wouldnt it be better to check the WarBirds one?
Regards,
GATT
4°Stormo Caccia
P.S.: my WB account has been closed some months ago.
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What Hangtime said (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
heeee heee he. Gatt! (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif) If BB wanted to single handedly start the worste riots and flame wars ever seen here then he should switch the MSCFS flight models used for comparion with the WB's ones.
-Westy
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Notice that the real P-51D could sustain a maximum of
3.5g, and could sustain its best turn at just a little over 3g giving 22.4 degrees per second (dps) and a 600ft turn
radius
22.4 deg/sec means 16 seconds in a sustained turn for a full circle. You´re absolutly sure that a P51 turned so good (afaik that´s the circle time of a zero).
600ft radius for a real P51. Afaik the Spit had ~1000ft, the fw190 1400ft. Again, absolutly sure? Which source do you have for this data?
Btw i think also that sustained turns with more G-load should be possible. When HTC change the code in this way that planes can fly sustained turns at much higher speeds the whole fightening will change. Planes will slow down less in hard turns, e-fight will become much harder, especially with laser guns. At the moment, "break turns"+ spray and pray is not a good tactic, this will change imo.
niklas
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Could someone explain how to read the diagram, especially with respect to
e-retension.
P.S. any chance of an online comparison in the future AH, WB, FA2, WW2online(when released). (also B17-2 and il-2 would be intresting when released of course)
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Can't wait for the hardcover edition of this book.
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jmccaul, this diagramm shows the flight limits of a plane. On the X-axis you have speed, y-axis shows the max. turn rate (degrees per second) that are possible.
A plane has several limits. It begins at slow speeds (let´s follow the blue line), here at ~78 knots. This is the limit of maximum lift-coefficient. The plane MUST fly right of this line, flying left is NOT possible, it would stall.
78knots is the stall speed at 1G, level flight. If you become faster (move right on the x-axis), you can fly MORE than 1G, that means you can turn without altitude loss. The Limit is not 1G now, follow the blue line up, and you see max Degrees/second increases AND max G-load what is possible with this airspeed.
So where can you turn fastest (for a short time of course) ? It´s the crossing of the line of max. Cl and max allowed stress.
At 6G the line hits another limit, the limit of maximum allowed stress!
And at 303 knots there is another limit, the limit of maximum engine power. You can see that you MUST fly less than 303knots to turn, or let´s say: Whenever you fly a endless sustained turn, you can´t fly with maximum level speed.
(Note, the line goes vertical down. That means if you START a turn from max level speed, for a short moment you can fly 6G-turn. Of course you will slow down very fast, but you can´t see this here, because it´s a static diagramm, it shows only one single moment of a flight, and not how speed etc. will change)
The engine limit for this sustained turn is the blue line between the limit of stress and 0G (level flight). It says to you for every airspeed how fast you can turn. At max. level airspeed, like i said already, you can´t turn logically. the point for max. level speed is also at 1G. The slower you fly, the more power of the engine is avaiable to fly turns- until you hit the point of maximum lift of the wing, at 3G.
Hope that helps
niklas
[This message has been edited by niklas (edited 09-07-2000).]
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Hey Badboy!
Good to see you've found Aces High and that you're still involved in the sim world. I've got myself involved with ThrustMaster, but still doing freelance work also. Do you still fly under the old handle?
Someone asked about the P38, here is a chart by Joseph Hong..
(http://members.home.com/viking11/images/energy1.jpg)
Viking1
[This message has been edited by Viking (edited 09-07-2000).]
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<throws peanuts at Hangtime>
Hah, you *really* think you can stop me?
Btw, you'll notice that the peanutes are half chewed.
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StSanta
JG54 "Grünherz"
"If you died a stones throw from your wingie; you did no wrong". - Hangtime
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jmccaul
The chart is called a 'maneuver diagram'. Here are the main points:
To begin with, the diagram has to specify specific parameters...altitude, weight, configuration, and power setting. For example, the parameters might be 'sea level, 10,000# weight, clean (no external stores), and War Emergency power (WEP). There is no such thing as a single diagram that describes flight performance at all weights and altitudes.
Now, let's look at the general shape of the diagram itself. For the given parameters, this is the flight envelope. There are three 'sides' to the envelope. The left side is the 'stall' line...the aircraft cannot fly at any point to the left of the stall line.
The right side is the max airspeed line. The aircraft cannot fly at speeds that are to the right of this line.
The top line connects the left and right boundaries. It is the aircraft G limit as set by the manufacturer. The aircraft may be capable of pulling more G than the diagram shows, but this would exceed the 'book' limits. G lines of lesser values are included below the top line.
The bottom axis is airspeed, and may be in True Airspeed (TAS) or Indicated Airspeed (IAS). It may be in knots, miles per hour, or Mach number.
The vertical (left) axis is expressed in degrees per second of turn rate and is a representation of how fast the aircraft can turn.
Turn radius lines are included in most diagrams. These originate at the diagram point of origin and project out to the right and up.
One last set of lines are usually included. These are curving lines that extend from the left line over to the right side of the diagram. Technically, these are known as Ps (pronounced Pee sub ess) lines...the definition of Ps is way beyond the scope of this thread. Think of the Ps lines as lines of equal maneuvering potential. The Ps lines have values ranging from zero to positive and negative numbers.
A positive Ps line means that the aircraft at any point along that line has an additional energy capability to climb or accelerate in excess of the current condition.
A negative Ps line means that the aircraft at any point along the line is losing energy, ie airspeed or altitude.
The zero Ps line is where the aircraft is just holding its own. It is neither accelerating or decelerating (or climbing or descending). The zero Ps line represents a sustained energy situation. To find the max sustained turn rate FOR THE GIVEN PARAMETERS, find the highest zero Ps point and go left to the vertical axis to read degrees per second.
The intersection of the stall line and the G line (upper left hand corner) is known as Corner Velocity. This is the minimum speed that the aircraft can instantaneously pull max Gs. In most aircraft, this point is a sharp peak in the diagram and is usually not sustainable. Remember, this is a value that pertains only to the given parameters of weight, altitude, configuration, and power setting. There are as many Corner Velocity speeds as there are changing parameters!
The significance of the Ps values is straightforward. The larger the number, the faster the aircraft loses or gains energy when flown at that point on the diagram.
Use these diagrams to gain an appreciation of where your aircraft is best flown for the given conditions. Use them also as a comparative tool to judge your performance with respect to other aircraft.
Andy
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I ask again, where did the curves for the "real P-51" come from? Flight test or calculation?
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Originally posted by Westy:
heeee heee he. Gatt! (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif) If BB wanted to single handedly start the worste riots and flame wars ever seen here then he should switch the MSCFS flight models used for comparion with the WB's ones.
-Westy
LOL ya got that right (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
Always appreciated the work you did for AW and ELO Badz. If you and Andy ever write the AH Strategy Guide, you got a pre-order right here (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Vladd
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Originally posted by MrLars:
Oh my gawd...Badz!
Can't wait for these articles but tell me, am I gonna have to suffer innumerable deaths from you here like I did in AW?
(http://bbs.hitechcreations.com/smf/Smileys/default/rolleyes.gif) <--lookin' up for Badz
Lars
Damn ... is this Badz? I too remember being on the wrong end of his guns way too many times in AW. Hope to cya up Badz.
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Hi Westy
Originally posted by Westy:
Hot damn! I though your interest had waned or other things in life had grabbed ahold of you when I noticed your postingss about the FM and such had tapered off a couple of weeks ago. Nice to see I had no fear of that. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Unfortunately the pressure of other flight sim' related work keeps me off the boards as much as I would like. I posted that message and then had to move my office again so I've been offline for a few days and I'd just like to apologize for the disappearing act.
I have to salute you Badboy for the way you write these up. I may not udnerstand all the fine details but your mastery in wording keeps me glued to the report(s). I'd be remiss not to mention again how much I liked your works when I saw them in AW prior to several of the scenarios there that allowed partipipants to get a better feel for how the aircraft of both sides could possibly match up against each other.
Thanks
And I chuckle now remembering sitting next to RM at the AW 1999 CON and tryin to track you down in the FT arena because he thought you had some kind of a cheat that allowed you to disappear when he was close on your "6" (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
I remember it well, it was a very fun weekend! I just wish I could have seen it from your perspective (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif).
Badboy
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Hi F4UDOA
Originally posted by F4UDOA:
You tease. I have been waiting to see your work for sometime now. Any chance of getting a sneak peak of the F4U??
I can't give you a sneak peak of the F4U because I haven't done it yet, I was always going to wait for 1.04 but now its here it will be high on the list, I promise.
Badboy
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Hi Funked,
Originally posted by funked:
Where on earth did you get an EM diagram for a real P-51? Is that based on analysis or flight test data?
It is a combination of both flight test data and analysis, it has to be because you can't produce them directly from flight test data, it isn't possible. If you want to produce such a diagram for a real aircraft, what is surprising is that the test schedule doesn't even include banking the aircraft. When I produce the diagrams for a flight sim they are easy to check and validate with banked turns, and I assume many guys check my results quite closely in the same way.
Badboy
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Originally posted by SOB:
Badboy,
However, your post has me quite interested, particularly in the RL to game to game to game comparisons. Thanks! I look forward to your articles (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
SOB
You are welcome, I'll try to make it interesting, and include only enough of the aerodynamics to keep any cynics happy (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Badboy
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Hi KampferAs,
Originally posted by LJK_KämpferAs:
Are you going to test the P51 for MSCFS1 or MSCFS2? cos the CFS1 a/c is way off, its about 2000lbs too light for starters, I have been through this in the past with CFS.
The EM diagram for the MSCFS1 P51 has been on my hard disk for a long time so I was going to use that, but if the next version is here before the article is done, I will use it instead, just to be fair.
Badboy
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Originally posted by MrLars:
Oh my gawd...Badz!
Can't wait for these articles but tell me, am I gonna have to suffer innumerable deaths from you here like I did in AW?
(http://bbs.hitechcreations.com/smf/Smileys/default/rolleyes.gif) <--lookin' up for Badz
Lars
I doubt that, I'm sure to be just another Dweeb for quite a long time. Getting to be good in a new sim' takes a big investment in stick time, and I can't log the hours right now. So perhaps this will be your chance to get even (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Badboy
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Originally posted by gatt:
Hi Badboy,
I like very much your AirWarrior EM diagrams. But, isnt a waste of time to analize CFS's Pony? Wouldnt it be better to check the WarBirds one?
A good point, thanks for the idea, I'll consider it.
Badboy
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Originally posted by niklas:
22.4 deg/sec means 16 seconds in a sustained turn for a full circle. You´re absolutly sure that a P51 turned so good (afaik that´s the circle time of a zero).
niklas
Don't forget, because that diagram is at sea level, with low fuel, it represents just about the best performance that the aircraft can achieve. As far as the altitude is concerned, I think a real pilot would need to be pretty desperate to fly on the edge of a stall at sea level, but that is where the turning performance is maximum! Certainly no real pilot would be crazy enough to do it as part of a test schedule, so validation is unlikely. However, move the test to 10,000ft with 75% fuel and the best sustained turn rate drops to around 16dps. Higher and heavier and the figure drops even more, not to mention other factors that will reduce the performance even further, but I'll elaborate on that more in the article. However, that's probably why any anecdotal evidence you may have is even more conservative.
Btw i think also that sustained turns with more G-load should be possible.
Then that should help you resolve your adverse impression of the quoted values because a higher maximum sustained g will always result in a higher maximum sustained turn rate. Also the turn rates quoted are the result of what I believe are quite modest sustained load factors.
Badboy
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Originally posted by jmccaul:
Could someone explain how to read the diagram, especially with respect to
e-retension.
Regarding e-retention, check the diagram below. I've included the curves of specific excess power (Ps). They indicate the rate of energy gain or energy loss in ft/s. You will notice that if you pull 6g in the old Aces High P-51 you would have bled energy at around 225ft/s that's the same as losing speed at the rate of ten knots every second. The 1.04 P-51 is better but I haven't quantified it yet.
I normally leave the other Ps curves off for clarity, and just show the Ps=0 curve because that gives you your sustained values. You only need to remember, flying above that line costs energy and the farther above it you go, the more rapidly the energy will be lost. Conversely, flying below the line allows you to accelerate, or climb while turning. Notice the Ps curve marked 20. That indicates that if you turn at about 1.5g, you can climb at the rate of 20ft/s or accelerate at a little less than two knots per second. Because I normally only show the Ps=0 curve, you just need to remember, the aircraft with the higher Ps=0 curve will sustain energy in the turns better than one with a lower Ps=0 curve.
(http://www.netcomuk.co.uk/~badboy/PDF/AH-P51-Ps.gif)
P.S. any chance of an online comparison in the future AH, WB, FA2, WW2online(when released). (also B17-2 and il-2 would be intresting when released of course)
Hehehe, that's a tall order, I'd probably have to give up sleep, to get it all done before folk stopped playing the sim's (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Badboy
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Originally posted by Vladd:
Always appreciated the work you did for AW and ELO Badz. If you and Andy ever write the AH Strategy Guide, you got a pre-order right here (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Vladd
Yep, I miss "Enemy Lock On" shame it went tits up. Andy and I would like nothing better than to do a book for Aces High, but unfortunately we have not yet found a way to do it that makes financial sense.
Badboy
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Originally posted by Exile:
Damn ... is this Badz? I too remember being on the wrong end of his guns way too many times in AW. Hope to cya up Badz.
Yep, it's me, but you don't have to worry, so far I'm just another easy target (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) But I'm improving fast (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Badboy
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Hi Viking
Originally posted by Viking:
Hey Badboy!
Good to see you've found Aces High and that you're still involved in the sim world. I've got myself involved with ThrustMaster, but still doing freelance work also. Do you still fly under the old handle?
B]
Yep, I've found Aces High, and enjoying it very much. I've never really been away from the sim' world, I've just been in lurk mode for a while (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) I thought Thrustmaster no longer existed? Recently I've been flying as either Badz or Badboy.
Badboy
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Thanks for the explanations (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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Big ole size 14 shoe PUNT!!
Wouldn't this be an opportune time for an article such as this? (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
-Westy
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Re-punt,
Tag your it.
Badboy where are you??
F4UDOA
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And now, for something completely different...
(http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
<PUNT>
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Badboy: I'm really looking forward to seeing more of these (even though I mostly fly the Pony anyway (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)). I'm also incredibly anal, so I'd appreciate it if you left the P lines in, maybe you could color the P0 line differently for the "L33+" generation.
Great work, looking forward to the complete thing. With all the explanations in here I'm actually beginning to understand the "envelope" concept (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif).
(http://hem.bredband.net/rickenbacker/images/ricksig.jpg)
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Rickenbacker,
Glad you are getting to grips with that stuff, the first installment is almost done and I'll be giving it to Andy Bush for his column on SimHQ. I discuss the P-51 quite a lot so you might find it helpful.
Badboy