Energy Maneuverability

[JG14_Josf]

Please Consider Energy Maneuverability

Before diving into the fight here I see an opportunity to introduce my axe to be ground into this fight, so as to leave less room for misunderstanding.

These Combat Flight Simulations are not new to me. The first Combat Flight Simulator I found was on the first Flight Simulator program offered by Microsoft, and it was a stick figure World War I hidden file in that program.

I went to Air Warrior, then Warbirds, then IL2, a brief look at Dawn of Flight, and now I have this Cliffs of Dover Combat Flight Simulator loaded onto an almost up to date PC.

I have been on Forums in the past, some of the regulars here may recognize my JG14_Josf username/handle.

My interest and concern has to do with accurate measures of relative performance and to that end my interest has to do with Energy Maneuverability.

Climb rates, top speeds, and sustained turn performance are distant secondary measures of Energy Maneuverability.

Please consider Energy Maneuverability.

I already checked this Forum, briefly, and I found this:

http://forum.1cpublishing.eu/showthread.php?t=34290

The basic Energy Maneuverability question has already been asked and that question is basically this:

Cornering Speed: "The lowest air speed at which a fighter can obtain the structural or aerodynamic limiting G force."

In the "dogfight" situation, this is the speed I'm trying to maintain in order to "out-turn" an adversary. It's also the speed above which I must excercise caution to prevent "Over-G" damage. Below this speed I must remain "Stall vigilant.

Is there a central location where the cornering speeds of CLoD aircraft can be found?

In the course of my interest in finding out accurate information so as to accurately measure Energy Maneuverability modeled into this Combat Flight Simulator I will be working the angles of attack that intend to reach the goal of answering that basic question above, and there are a few vital questions that are derived from that basic, or principle, question.

Such as:

1.
Are pilot g force limits equal for every on-line user of the game?

2.
What is the pilot g force limit for any on-line user of the game?

3.
Are any of the Fighter Planes modeled in the game with structural g force limits that are lower than pilot g force limits; therefore a pilot can break a plane before a pilot blacks out in this game?

Game = Combat Flight Simulator

I hope that my interest is well received here, and I further hope that all animosity can be set aside in a mutual interest in finding the facts, documenting the facts, and avoiding misunderstanding, confusion, misdirection, division, etc.

There are many reasons I can report here as to why these questions are vital as the Corner Velocity question exemplifies, since accurate information that accurately reports Corner Velocity is nearly the full measure of which plane is superior to the other plane in Aerial Combat.

I will try to recover my lent out copies of Fighter Combat by Robert Shaw, and Boyd by Robert Coram, and many other previously uncovered reports of vital information that can support the viewpoint that Energy Maneuverability is worthy of our mutual interest.

Corner Velocity is reported on the charts posted in the thread linked above, and I hope that I am not bending the rules too much by re-posting them now, since there are other comments that I think are vital as to these charts that report Relative Performance including Corner Velocity (instantaneous turn performance) and Sustained Turn Performance.





Questions concerning those numbers:

1.
Are those numbers accurate representations of averages for production planes?

2.
Are those numbers accurate for 2 specific actual airplanes?

3.
Are those numbers based upon actual flight tests?

4.
Are those numbers based upon calculations and if so who did those calculations, which formulas were used, and which data was used in those calculations?

5.
Are the 109 Stall Lines (accelerated and sustained) based upon open or closed leading edge slats?

6.
What exactly is meant by Full Throttle, does it include any additional settings having to do with maximizing manifold pressure or air/fuel mixture such as might be considered to be Combat Power?

7.
Is there any information about game performance that is available (so far) to be able to plot out that same type of Chart which is an Energy Maneuverability type Chart.

Examples of Energy Maneuverability data can be found here:

http://www.aviation.org.uk/docs/flig...-FTM108/c6.pdf

Scroll down to:

Turn Performance and Agility
Figure 3.63
Turn Performance Characteristics

I hope that this can be a good start to a mutually beneficial discussion concerning Energy Maneuverability as this type of data can be documented and understood from historical data to actual game data whereby the interest is knowing accurate relative performance characteristics.

To that end there are multiple methods by which game performance can be precisely (within obvious tolerance limits) documented, so as to leave out subjective opinion (as much as possible).

[Kurfürst]

Welcome back Josf. I have missed those charts.

[JG14_Josf]

Thanks for the welcome back, Kurfürst, and it is encouraging to see that you continue to offer a well communicated viewpoint, and I hope that we can avoid repeating any irreconcilable contradictions that may have been generated in the past.

To which I will now attempt to communicate more information concerning the Energy Maneuverability angle of view generally and the corner velocity measure specifically.

To help broaden the scope of the data pool beyond those 2 charts that concern the 109E and the Spitfire, please consider helping in identifying the specific information being reported by utilizing the Navair Information and an additional example of the same type of EM Chart.

I can't (yet) cut and paste the Navair information other than text (no chart):

TURN PERFORMANCE AND AGILITY
6.51
Frontside
Backside Envelope limit
Line of constant
Windup turn
Steady turn,
Loaded acceleration
Loaded deceleration
Area of positive
nz
Ps
Ps= 0
V
L Vs Vmrt
True Airspeed - kn
V
T
Turn Rate - rad/s
w
Coincident
Boundary
NOTE: Lines are "thickened"
for distinction
Figure 6.36
TURN PERFORMANCE

I can borrow another chart:



Source:

http://www.sci.fi/~fta/JohnBoyd.htm

All that above may be GREEK to anyone sharing this interest in Accurately Measuring Relative Air Combat Performance.

RECAP:

Cornering Speed: "The lowest air speed at which a fighter can obtain the structural or aerodynamic limiting G force."

In the "dogfight" situation, this is the speed I'm trying to maintain in order to "out-turn" an adversary. It's also the speed above which I must excercise caution to prevent "Over-G" damage. Below this speed I must remain "Stall vigilant.

Is there a central location where the cornering speeds of CLoD aircraft can be found?

Obviously, to me, there is at least one other person who understands the significance of Corner Speed.

Please know the difference between Sustained Turn Performance and Accelerated or Instantaneous Turn Performance so as not to confuse the two.

Consider how much confusion might occur if someone were to confuse Accelerated or Instantaneous (Corner Speed) with Sustained Turn Performance with an example illustration.

Fighter A is dropping from a higher speed and higher altitude into the circle produced by Fighter B as Fighter B is maintaining or sustaining a level flight turn at Maximum Performance for a Sustained Turn.

Fighter A drops in behind Fighter B from higher altitude and higher speed, and the question that is asked will offer the reader an opportunity to test your understanding of Energy Maneuverability or Air Combat in general, to see if you are confused or not confused about the differences between Sustained Turn Performance and Instantaneous Turn Performance.

This is vital stuff, and if you are confused you may not even be able to recognize how vital this stuff is in fact.

Question:

Which plane will be able to turn a smaller turn radius and a faster turn rate when Plane A is dropping down into the turn of Plane B where Plane A is at Corner Velocity when it begins to track Plane B and where Plane B is maintaining a Sustained Turn at Maximum Sustained Turn Performance?

The answer must include a g force tolerance number for each pilot and so an arbitrary number can be added to the question so 5 g can suffice as the constant that is demanded in order to answer the question.

Plane A (Can be a Spitfire against Spitfire, 109 against 109, Spitfire against 109, Mig against Mig, F86 against F86, Mig against F86, Spitfire vs Mig, 109 vs Mig, etc.)

Plane B (can be any plane on those charts too)

Plane A is at the 5 g (pilot limited) Corner Speed at the time it dives into a tracking shot onto Plane B.

Plane B is flying a luffberry circle at Maximum Sustained Level Turn Performance Flight Path (Level turn at full throttle just above the stall or at CLMax angle of attack).

Which plane (Plane A or Plane B) in any case will turn inside which other plane when the assumption is that both pilots cannot tolerate more than 5 g?

Solve the question for 5 g as the pilot g limit - please.

Note: EM Charts can be made for each plane in the game by following the methods described in the Naviar link.

[TUSA/TX-Gunslinger]

Originally Posted by Kurfürst

Welcome back Josf. I have missed those charts.

+1

I'll take Josef's apprearance as a sign of good luck!

[335th_GRAthos]

As I had guessed.

WinXP will unfortunately not take you very far I am afraid. Most likely you will need to upgrade to Win7 and at least a 4core CPU and a good graphics card (2Gb VRAM or more).

As you gain experience, you will begin to realise the constraints...

I also wonder why 1c does not provide us with data, I asked and got the reply I posted earlier.

Enjoy flying!

[JG14_Josf]

As I had guessed.

I do not know what that means.

As to the advice of moving up to Windows 7, again off-topic, the advice is sound enough since that was the way I went to actually get the game to work.

As to the other advice, or challenge, to actually fly Combat Maneuvering I can reply to anyone including TUSA/TX-Gunslinger whose handle sounds familiar in my long term memory concerning those efforts to discuss the topic on the IL2 Forums if not earlier.

So far in Clod our Squad, which is now a combination of JG14 and IV. JG53, has our first organized mission scheduled on the ATAG server for tonight, Sunday, and we plan on Simulating a small scale, escorted, bomb raid on an airfield or radar station - type mission.

This is off-topic too.

In preparation for that mission I have spent time with the Squad and time alone off-line, becoming more familiar with the game. Our teamwork is returning to some semblance of effectiveness in Combat Air Patrol, Hit and Run, Drag and Bag, Mutual Support, Line Abreast Formations, etc. On my own I have repeated a Target Practice Off-Line Drill (Training) with Single Player Quick Missions involving a mid altitude frontal attack on a formation of light twin engine bombers. Bombers that look almost like a twin engine Bonanza, King Air or whatnot.

The gunnery is more difficult than IL2, so far, as expected, and during this Drill I can shoot at multiple air targets from many angles since the King Air type twin bombers have meek gunners and top down or bottom up attacks tend to avoid the tracking capacity of the A.I. gunners, as expected.

During the continuous zooms and dives during the repetitive Gunnery Drill it is becoming clear that the Flight Model, and Pilot physics model (or whatever is the term for modeling black out and alterations in control of the plane) are not the same as in IL2, and to me, so far, the feel of control, loss of control, buffet, stall, slowness of response to control inputs under load, etc., are better that IL2, including the Stall, as exemplified by the methods used to recover from a Stall, or the methods used to avoid a stall: there appears, so far, to be more feedback (sound or response time = I do not have Force Feedback but if there is a good Force Feedback stick then I think this game may drive me to get one) on the edges of the flight envelope, which allows the pilot to remain in the flight envelope while utilizing those "signs" that inform the pilot of impending departure (buffet for example).

That brings me to the point at which the topic may return into view as the Gunnery Drills I have been running may include an ending Windup Turn Test as described in the Navair Web site. In other words I have begun to quantify Corner Speed for the 109.

So far, with the 109, I have Corner Speed (Pilot g limited not plane g limited) at about 350 km/h indicated. If I fly at 400 km/h for the Windup Turn Test the plane, so far, buffets and eventually sticks into a more or less coordinated diving turn, where the airspeed indicator is showing a needle that is dancing around, and my ability to smooth the turn out is as yet not refined enough to nail down an Instantaneous Maximum Performance Turn well, but the initial test confirm that 400 km/h is definitely above the pilot g limited Corner Speed since it is possible to grey out the pilot.

So far I have not blacked out the pilot as was possible in IL2, where the screen goes black (or grey if the software was exploited in some versions I've heard) and the pilot is no longer able to control the controls of the plane for some time that could "feel" like an eternity.

I've tried to target 300 km/h as Corner Speed in at least one Windup Turn Test so far and so far that appears to be under Corner Speed since the effort to reach black out was an effort that found buffet, severe buffet, and then stall before grey out was even possible.

Returning to Naviar, to return solidly on the topic, the following is a restatement of the definition of Corner Speed and a restatement of the Windup Turn (for anyone who may be interested in the topic):

6.3.4.6 CORNER SPEED
The significance of the corner speed can be seen in figure 6.15. At the speed corresponding to the intersection of the lift boundary and the structural limit, the minimum instantaneous turn radius and maximum instantaneous turn rate are achieved. Thus, VA is the speed for maximum turn performance when energy loss is not a consideration.

6.4.1 WINDUP TURN
Instantaneous turn performance is documented usually with the windup turn technique. In this technique the load factor is smoothly and steadily increased with constant Mach number. The end point of the data run is the accelerated stall or the structural limit, whichever is reached first. To perform the windup turn, momentarily stabilize at the desired Mach number. Set the thrust for the test as you roll into a turn and smoothly increase load factor. As load factor and drag increase, reduce the pitch attitude in order to keep Mach number constant. Use bank angle to adjust the pitch attitude. When the limit condition is reached, record the g level. Increase the load factor no faster than 1/2 g/s to minimize the effects of unsteady flow.

In the game, in place of "record the g level" is a condition of simulation whereby the user of the software will either find black out or the user of the simulation with find the stall.

If the user of the simulation finds black out, then the user of the simulation has found out where the game software determines Corner Speed for that plane, but only if the user of the software (any user) can't reach black out at a slower speed.

If one user of the game software (without cheating some way) can fly slower and reach Black Out at a slower speed, then that user will be turning a smaller radius at a faster rate than the user of the game software who cannot pilot the plane at a slower Corner Speed.

If one user is hamfisting the controls, or has very poor hardware, or for whatever reason (other than comparing a cheater with an honest player) is stalling at the same speed than another user flying at black out (or in grey out, which should be before severe buffet), then it is the Player that is not "feeling" well, not the software playing favorites, assuming that both pilots are flying the same plane configured the same way, with the same amount of fuel, total weight, flap setting, etc.

This is where the rubber meets the road, and the Forum users are no longer fighting with English words, and the game software users are fighting with simulated airplanes in simulated air combat: back to the topic.

The region of buffet, or that place in the real (or well simulated) flight envelope where Maximum Turn Performance, Maximum Lift, CL Max, highest turn rate, lowest turn radius, lowest Corner Speed, and highest g limit (pilot not plane limited) is FLOWN, and to go past the initial instances of buffet, to fly beyond the beginning of buffet, to hamfist the controls past the most efficient angle of attack, and to enter well into the buffeting zone of wing angle of attack, is to reduce turn rate, increase turn radius, lower g load, and slow down below Corner Speed IN FACT.

So...practice may make worse, or more experience may help in finding the TRUE Corner Speed as the developer has modeled into the present form of the Software.

That may be what this means:

As I had guessed.

I don't know what that means, I guess that I am supposed to guess what that means, so that is my guess - in English.

That is off-topic.

On topic is that the 109 Corner Speed, so far as I can tell, is about 350 km/h indicated and relevant to about 2,000 meters altitude in a shallow diving Windup Turn Test Off-Line where this pilot was well into the buffet zone during that test, so that One test so far may be well off the precisely identified software coded Corner Speed.

If someone can fly the 109 in a Windup Turn Test at 300 km/h and reach black out, then they may be doing the test with a lighter fuel load, which is entirely possible, since I have so far done all my testing starting with full fuel.

More weight will move the Accelerated Stall line to the right on a Maneuvering Diagram (accelerated stall line), assuming that I understand Energy Maneuverability well enough.

Note: If a plane was loaded very heavy the Maneuvering Diagram (accelerated stall line) moves so far to the right that the 1 g stall is past Top Speed Level Flight and the plane can never take off on Earth, it can roll down a runway going all around the planet and never reach the Corner Speed or even the Take-off speed, since it is so heavy that the wings stall before 1 g. How would that look on an EM Chart?

Since more weight will move the Accelerated Stall line to the right on a Maneuvering Diagram, which is merely a record of how changes in weight cause the plane to stall at a higher speed (less weight) or lower speed (more weight) the heavier plane (same plane with more weight loaded) will have a higher corner speed, which means it will turn a larger Maximum Performance Turn Radius, and the heavier plane will turn a slower Maximum Performance Turn Rate, and the heavier plane (same plane loaded with more weight) will reach the SAME pilot g load unless the game software changes the pilot g load tolerance as the plane is loaded with more or less weight and that returns to the warning concerning Game Developer Transparency and how to get around the lack of information made available.

Windup Turn Tests document Corner Speed. Some users/players/gamers/flight sim pilots/combat flight sim pilots, whatever, may be better (not cheating) at reaching the Software CODED Corner Speed compared to another player - all things being equal (not cheating or not using a different fuel load, different testing altitude, different plane, etc.) - all things being equal except the Game CODED software as it was CODED by the developer and not re-CODED by the player who may mod the code to get a better Corner Speed (any exploit not yet know by anyone other than the person doing the exploiting).

Some players can be trusted as players who would never cheat, other players can be trusted as players who will always cheat if they are afforded any opportunity to cheat.

That is off-topic.

This is on-topic:

Cornering Speed: "The lowest air speed at which a fighter can obtain the structural or aerodynamic limiting G force."

In the "dogfight" situation, this is the speed I'm trying to maintain in order to "out-turn" an adversary. It's also the speed above which I must excercise caution to prevent "Over-G" damage. Below this speed I must remain "Stall vigilant.

Is there a central location where the cornering speeds of CLoD aircraft can be found?

My initial, rough, tests peg the 109 Corner Speed (heavy with fuel) in between 300 and 400 km/h, at about 350 km/h.

Note: Changes in weight may not change Corner Speed significantly within the normal ranges of Combat Weight for any given plane while changes in weight may be more significant concerning changes in Sustained Turn Performance which may be a function (theory on my part) of that all too familiar squaring factor of drag as airspeed increases.

Sustained Turn Performance is flown at a much lower airspeed compared to Maximum Turn Performance and therefore the Total Drag is exponentially higher (square with velocity) at the higher Corner Speed relative to the lower Sustained Turn Performance (lufberry circle) Speed - if I have this understood.

JG14_Josf offers an initial estimate of 109 Corner Speed to be 350 km/h.

Flying slower than 350 km/h is increasing the difficulty of reaching black out before stall.

Flying faster than 350 km/h is increasing the ease at which the pilot can generate enough g force to black out the pilot instead of stalling.

Maximum Turn Performance is the condition of flight where the higher g force is generated at the lowest possible airspeed, and then the turn radius is the smallest possible turn radius, the turn rate is the highest possible turn rate, air speed is slowest while g force is highest (pilot not plane g limit).

That is on topic.

[Jam656es]

I already checked this Forum, briefly, and I found this:

[335th_GRAthos]

Hi Josf,


It has been very many years, welcome back.

A piece of advice: Do not even bother...

This flight sim, at the current state, is miles away off target in terms of a.)transparency and b.)historic performance of flight models.

On the positive side, the climate of this forum and the friendliness of the fellow members towards each other makes everybody want to hang around and enjoy reading!



Enjoy


~S~

[JG14_Josf]

Il-2 enthusiast & Moderator

Please, moderator, let me know if your displeasure is such that you prefer that I do not continue any further discussion on this topic or on this forum for that matter.

I prefer not to be involved in forums where the moderators contribute to Flame wars.

[JG14_Josf]

This flight sim, at the current state, is miles away off target in terms of a.)transparency and b.)historic performance of flight models.

335th_GRAthos,

The concept of documenting the actual game performance concerning those plots that go on those charts so as to then accurately know where the current state of the flight model is and then to accurately know what is changed in the flight model is specifically demanded as my intended interest with this topic on Energy Maneuverability.

I failed to make that clear within the context of the first initial volley.

I may not be employing English very well.

If it can be known as to...

I can borrow again:

Cornering Speed: "The lowest air speed at which a fighter can obtain the structural or aerodynamic limiting G force."

In the "dogfight" situation, this is the speed I'm trying to maintain in order to "out-turn" an adversary. It's also the speed above which I must excercise caution to prevent "Over-G" damage. Below this speed I must remain "Stall vigilant.

Is there a central location where the cornering speeds of CLoD aircraft can be found?

If that can be known now, then any changes can be known later.

I hope that I can address this:

This flight sim, at the current state, is miles away off target in terms of a.)transparency

I prefer to address that before addressing this:

and b.)historic performance of flight models.

The question asked, if you please, could be answered, and I'm not begging the question, I am merely asking you personally, please, and thanks for the welcome, please engage in the discussion on the topic by entertaining an answer to the question concerning Plane A (Sustained turn) and Plane B (Diving in at Corner Speed), and which plane turns a smaller radius at a faster rate, and there can be three levels of answers relevant to the game and to this topic.

Assuming a 5 g pilot limit.

1.
The answer is provided by the 109 and Spitfire EM Charts, which are not superimposed one on top of the other. (WWII vintage?)

2.
The answer is provided by the Mig and F86 Chart, which has one plane superimposed on the other plane. (possible flight test data plotted onto that chart by John Boyd and Chuck Yeager concerning a captured Mig).

3.
The answer is provided by game flight tests. (I don't even know yet if the game offers usable information recorded in replay files).

Again addressing this:

This flight sim, at the current state, is miles away off target in terms of a.)transparency and b.)

Having in-game data, if it is accurate (repeatable from one computer to the next and from one test pilot to the next and from one test flight to the next or by average of many test flights), there can be a mathematical determination of which planes, which pilots, are blacking out at which g loads.

Note: In IL2 it became obvious that some planes were modeled to generate higher g loads and therefore that program was thereby able to vary Instantaneous turn performance for those planes so modeled relative to the planes that were not modeled with pilots that were not capable of sustaining as much g force.

Someone might ask me, or ask themselves, how can it be possible for someone to know if the game models the same g load for each plane?

That is the same point, the same question, as this Topic intends to answer.

If someone were to have two computer side by side and one pilot is turning the same diving turn as the other pilot, both pilots are following the highest performance downward spiraling turn, and one pilot is no where near black out while the other pilot is obviously being limited by black out, and both planes are nose to tail in the diving turn, what do you think that proves?

If you care to engage in the discussion: please consider answering the question.

I know for a fact that the IL2 game became widely variable in which planes were modeled with higher or lower g loads, depending upon which "mod" was being modded by whoever figured out how to alter that variable.

I know for a fact that I had asked many times on those IL2 forums if the game modeled the same g load for each pilot and as far as my memory goes I think the official answer was that the pilot g load was 5 g for every pilot flying every plane. That was later proven to be untrue, but the cause of the variations are probably attributable to modifications done to the original program.

How important is it to have a 1 g advantage in modeling for your pilot when you fly your plane against an opponent where the opponent is flying with 1 g less tolerance in g load; where your opponent is fighting against black out, right in front of you, and you ask him on Teamspeak, and the opponent confirms on Teamspeak, "I am fighting black out", and you in your plane can merely pull back on the stick, no black out, pull lead, start shooting, score hits, and so, again, how important is it to know if your plane, and your pilot can tolerate the same g force, more g force, or less g force, and how important is that information compared to which plane can go 5 km/h faster on the deck, or which plane can maintain 1 g more in a luffberry circle or sustained turn at a constant altitude?

I'm asking, and I think I am asking nicely, and already the moderator is starting a flame war?

What is up with that?