the turn fight and why it kills

[Sonicblu]

Firstly, this example was taken from the highly unlikely situation of two pilots flying Spitfires in a duel and staying at 250mph and 3G, but now we discover they were both also not even at full throttle. But I doubt that anyone would get the impression that you should begin a duel by entering a 3G flat turn while throttled back? After all, that is so unrealistic it is almost absurd. But since it isn't even credible, and since even new players learn fairly quickly that you need to pull more than 3G if you are trying to out turn someone, and your speed won't really stay at 250mph for long, no real harm done... after all it is only an example right? 

[/quote]

hmm I thought it was the discription of just one circle or two in the fight. I didnt even get the impresssion that it was a discription of begining a duel.

It seems you have made some assumptions I didnt even think about. You went from something specific to some generalizations. While you might be right about the context of the fight I'm not sure you can apply it to certain specifics of the poster.

I've had many a duel end in the luftberry I think its called or the circle fight. At that point it seems to me that the crutch has a valid point.

Are you saying given that exact senario it would work differently.  I always lower throtle to help turn inside the bandits circle. Or go full throtle and try to use speed and offset the circle.

[Badboy]

I didnt even get the impresssion that it was a discription of begining a duel.

You didn't need to get that impression, take another look at the quote below:

How does this translate to an actual fight?

Example:
Two pilots are fighting a duel,

You see that it was stated explicitly by the original poster.

It seems you have made some assumptions I didnt even think about.

No assumptions were required, the conditions were explicit. 
 

I've had many a duel end in the luftberry I think its called or the circle fight. At that point it seems to me that the crutch has a valid point.

Nope, the original poster's conclusion was wrong, as previously explained in some detail. If you aren't clear about any of the points I've made, feel free to ask a specific question and I'll try to clarify it for you.

Are you saying given that exact senario it would work differently.

Yes, that is exactly what I've already said, and I've explained why in previous posts. If there is anything you didn't understand about any of those points, just ask and I'll try to clarify it for you.

I always lower throtle to help turn inside the bandits circle.

Given the conditions set out in the original posters example, that is of two Spitfires, both at corner velocity in a flat turn trying to out turn each other, reducing throttle would be the wrong thing to do. It won't reduce your turn radius, but it will reduce your turn rate, and allow your opponent to out turn you. Of course there are situations when reducing throttle may be appropriate, but the situation we are discussing isn't one of them. So, if that's what you do under those circumstances then you are making a mistake.

Badboy

[Badboy]

Hi,

After looking at this old doghouse plot for an Aces High Spitfire comparison, I just wanted to illustrate my previous post in the hope it helps.



In the original posters example, the Spit9s are at 250mph, which is actually about 32mph above their corner velocity. However, at 250mph a maximum rate turn at sea level results in negative Ps of -126 ft/s which means that in a flat turn the aircraft would decelerate to corner velocity in under 4 seconds. Reducing throttle would just mean that your opponent would enjoy those high instantaneous turn rates for a little longer than you, during which time he would gain angles. You also notice that once you reach corner velocity and continue to slow down, your turn doesn't tighten, and your turn rate drops, so reducing throttle won't help you "turn inside the bandit's circle" it will just make your situation worse and cost even more angles. So, once again, if your goal is to out turn the bandit, more power really does help.

Is that easier to see?

Badboy         

[crutch]

not really, since Im not entire sure of the parms of the graph.

verticle is degrees/sec
horizontal is speed

know what the G-lines are

not sure what the radials are (400,500,600, etc)

[Mace2004]

not sure what the radials are (400,500,600, etc)

Turn radius in Ft.

[crutch]

and the curved colored lines leaning to the left?

[Badboy]

and the curved colored lines leaning to the left?

Those are the Ps=0 curves. They indicate the points in the envelope where there is zero specific excess power. Just think of it as the sustained turn line, because this aircraft can just sustain a turn at points along the line. At points below the line it can turn and climb or accelerate at the same time. For points above the line, it will need to descend or decelerate. Where the Ps=0 curve intercepts the lift limit, that is the stall line, indicates the point where the aircraft has its best sustained turn.

The diagram below is for the Spit9 only, so it is a bit clearer and is more uptodate, and includes Ps curve at 25ft/s intervals.     



As an example, if you look at this diagram, you can see that if you pull a 5g turn at 225mph, you will have a turn rate of 27.4 dps with a radius of 691ft and a negative excess power of -75ft/s which means that if you want to hold that turn you will either need to descend at a rate of 75ft/s or decelerate at just under 9mph/s. The best sustained turn is 23 dps, and the best instantaneous turn is 34 dps at corner velocity where you have a maximum negative excess power of -141ft/s, which means you lose energy most quickly at corner.

You can tell how one aircraft will perform against another by overlaying the diagrams. 

Hope that helps...

Badboy

[SAJ73]

In my opinion I think Badboy really makes some good points in this discussion! Just like I recognize turnfighting from my own experiences. Even if I am not an expert on the subject..
I like to turnfight alot myself in DA, infact I do it as much as I possibly can. Too much some might say.. Because I tend to put myself in those positions where there is no other way out.

I actually think I heard someone give me a comment on the VOX in DA earlier tonight about me always being in trouble no matter what! Not sure if it was to me, but it sure sounded alot like me!  I did not bother to comment on that, but that's the way I want to learn how to get better. By getting myself into trouble so I can learn how to fight my way out of it.. I rarely survive for long, but I learn alot by doing this over and over again.

And I know this for a fact, if I let down on my trottle while in a hard turnfight I will lose the turn for sure! I go down on the trottle if I am too fast to get the plane in the hard angle, or just a tad to get the flaps out.. But when the flaps are fully deployed and you get the plane on the limit of flippin over you really want all the power you can possibly get to gain on you opponent without falling out of the sky! 

[Sonicblu]

Badboy,

I think i understand. I guess it helps to stay real specific.

I dont think I was ever at cornering velocity.

So If we are going faster than corner velocity. Say 250 then i reduced throtle to 220 would it be a smaller circle or out turn him.

Would that be the right situation.

Thanks.

[FLS]

If you have the option it would be better to get your nose up to bleed speed faster while holding your 6G turn. You'll lose less E because you're climbing. Drop your nose as your speed drops to 220 to try to maintain corner velocity.

[crutch]

If I understand your second graph then this is true;

the 3G line intersects the Ps=0 line at about 270 or so.

If I reduce speed, all the way to stall speed at about 155, while holding 3 Gs, I have excess energy to work with.

this energy, I can use to increase speed, pull more Gs or gain altitude (mainly by using top rudder to point the nose above the horizon), is this correct?

also the formula, I posted at the beginning is within rounding errors of the Gs/Speed/radius points on the graphs.

since there is no altitude component to the graphs, speed is probably IAS instead of TAS.

[Gunzo]

I actually think I heard someone give me a comment on the VOX in DA earlier tonight about me always being in trouble no matter what!

I know that feeling

Gunzo

[Badboy]

So If we are going faster than corner velocity. Say 250 then i reduced throtle to 220 would it be a smaller circle or out turn him.

If you are trying to out turn an opponent in a level turn starting at 250mph and you are turning as hard as you can, reducing throttle is not the right thing to do. Let me explain why. Take a look at the Spitfire diagram again, at 250mph if you pull all the way to the G limit, you can generate a turn rate just under 30dps. Your speed will drop rapidly, but your turn rate will increase up to 34dps when you bleed to corner, and your turn rate won't drop below 30dps until your speed bleeds below 192mph.

Those are incredibly high turn rates that you can only enjoy for a short time, because at corner velocity you are losing speed at the rate of almost 10mph every second. The faster you lose speed, the less time you get to turn at the best turn rates. You are suggesting reducing throttle and spending even less time turning at those high turn rates. If you could get enough engine power to turn at corner velocity without losing speed, in AH you would be able to turn at 34dps as long as you wanted, you would have a better sustained turn rate than any other aircraft in the game.

More power gives you higher sustained turn rates, and allows you to enjoy higher instantaneous turn rates for longer, in a rate war, the more power the better. There are times when reducing throttle may be the right thing to do, but not when you are simply trying to out turn an opponent in a flat turn.

Hope that helps...

Badboy

[TequilaChaser]

Altitude is posted on the EM Chart at the top Right corner  0 ft = ASL ( At Sea Level )

when ever one is looking for a planes performance and comparing plane performance, you should be reading TAS ( True Air Speed )

most every chart or graph in exsistence whether it is for Real Life WWII planes or for different flight sim's planes, are showing TAS........ ( provided the guy making the graph is knowledgable )

for me, and my thoughts, I use IAS speeds when teaching to others, in helping them get a feel  of what speed is needed for certian BFM's, maneuvering and so forth...

using top rudder is going to scrub more energy, and is not advised most of the time, because one would be cross controlling....... I am not saying never to use opposite rudder ( in this case Top Rudder as you have described ), but sometimes opposite rudder can be of benefit.....

hope this helps......

[Badboy]

the 3G line intersects the Ps=0 line at about 270 or so.

Yes, and so at that point you could just hold 3G in a flat turn without losing speed or altitude. 

If I reduce speed, all the way to stall speed at about 155, while holding 3 Gs, I have excess energy to work with.

No, if you fly on the Ps=0 curve you have no excess power. The point you are referring to is the point where you have the best sustained turn rate. A very significant point because sustained turning ability is a very important factor in a turn fight. For example, in the previous diagram comparing the three Spitfires, you will notice that the Spit8 has the best sustained turn rate, and has the highest Ps=0 curve of the three, so it will maintain higher turn rates for longer. However, at all points along the Ps=0 curve the aircraft is not losing or gaining energy, no surplus at all. 

also the formula, I posted at the beginning is within rounding errors of the Gs/Speed/radius points on the graphs.

Nope, in your calculations you have ignored the effect of gravity. The aircraft in the flat turn you have described "they are in full knife edged (90 degree) banks." would be falling out of the sky like rocks. For example, on the EM diagram a 3G turn at 155mph shows a turn rate of 22dps and a radius of 568ft. Your calculations would give a rate of 24.3dps and a radius of 535ft. That's only a difference of 32ft, not very significant in combat, but certainly not a rounding error. However, the turn rates show a difference of about 1.4dps and in air combat that is a big difference, because a difference of 2dps is normally considered decisive. The difference involved isn't rounding error, it is the difference that arises from the fact that in a flat turn the radial G, that is the G doing the turning, needs to be less than the body axis normal load factor pushing the pilot into his seat, because of the vertical G required to compensate for gravity and prevent the aircraft from falling out of the sky. 
 
Hope that helps...

Badboy