Which is exactly what I said to begin with. The guy who can pull closest to that edge without stalling wins.
Yes, well, it does depend on the situation and plane type as I have demonstrated, but it does work well as a general rule to start out with.
That diagram is useful for learning the F4u-1's maximum sustained and instantaneous G, rate, and radius at various speeds with no flaps down. Badboy made another diagram that showed the best sustained rate (and the radius that came with it) for each of the flap settings for the F4u, which showed 2 notches made the best rate, and is what I keep basing the 2 notches for f4u is best on.
However, neither of them can demonstrate what happens while you dump all of the flaps and burn your speed down until you get to the best speed the F4u can generate at the best rate turn for the full flap setting.
Edit: I should have thought to describe "dump all of the flaps and burn your speed down until you get to the best speed" as an instantaneous turn. Here is a post by Badboy on flaps and what they do to rates, take very special note of the third paragraph under his a6m chart:
Some players make good use of flaps, others don't. For the most part, we learn how to employ flaps from experience, but in some cases, even after significant experience it is still all too easy to get it wrong. One reason for this is the difficulty getting the quality experience in the first place and also the difficulty getting good information.
Before I give you my take on this I need to make some general comments on the use of flaps in air combat. It is fairly commonly known that using flaps changes the camber of the wing and that this changes both the lift and drag. Most players are aware that the lift increases, and the drag also increases, but what is important is the ratio between the increase in lift and drag and that ratio is known as the aerodynamic efficiency. Depending on the type of flaps and how much they are deflected, the influence of the flaps on the profile and induced drag in proportion to the lift can result in either an increase or decrease in the resulting aerodynamic efficiency of the wing. What that means is that the use of flaps can be good or bad in terms of the price you have to pay for the increase in lift.
What does that mean in terms of air combat? During an engagement, the differences in lift and drag are apparent by the influence on the way our aircraft can turn. Employing flaps generally results in higher instantaneous turn rates, and a smaller turn radius. However, in the case of a sustained turn, while the turn radius is always reduced, the sustained turn rate may either increase or decrease.
In cases where a particular flap deflection results in a reduction in turn radius, and an increase in the sustained turn rate, it is very important to identify that, because it can be highly desirable to fly in that configuration. However, it is more common for a reduction in turn radius to be accompanied by a reduction in the sustained turn rate. In those cases it is essential to know when you need to minimise your turn radius, or when it is more important to maximise your sustained turn rate.
The answer is this… Generally, (I need to speak in general terms because there are exceptions and I will come to that later) it is better to minimise your turn radius in a one circle fight (nose to nose turns) and to maximise your turn rate in a two circle fight (nose to tail). This is a very important point, it is so important that many players lose fights because they fail to understand the subtleties of it.
In order to make best use of the differences in radius and rate caused by the use of flaps, it is necessary to know how your turn radius and turn rate are influenced by the use of flaps in a sustained turn. That information is conveyed most readily by means of a diagram showing the turn circle for a fixed time. That way the turn radii can be seen relative to each other, and because the circles are drawn for a fixed time, the differences in sustained turn rates will be apparent because some lines will extend farther around the circle than others. You can see this by inspecting the following diagram.
(Image removed from quote.)
Here you can see that the F4U1D benefits from a tighter turn radius and an increased sustained turn rate when flaps are employed. You will notice that the best sustained turn rate occurs when the flaps are deflected by two notches. That's the best place to be in nose to tail fight, because the way to win that kind of fight is simply to win the turn rate war. You need to gain angles on your opponent until you move around the circle onto his tail. In order to do that you need to know how to maximise your sustained turn rate. The diagram above shows you exactly how to do that.
You can also see that if you deflect the flaps on the F4U1D beyond two notches, you pay for it with a reducing sustained turn rate. Notice also that once you get to four notches, the fifth and final notch gives you a slightly tighter radius with an insignificantly small reduction in rate. So for this particular aircraft, once you enter a turn fight, you should use only two notches of flaps as long as you are turning nose to tail to optimise your rate, and if the fight goes nose to nose, such as in a scissors, where you need to reduce speed and minimise your turn radius, use full flaps.
Lastly, if the situation changes don't be afraid to work the flaps. If the fight is nose to nose and you employ full flaps as appropriate in that case, but the situation changes to one where you find your self chasing the bandits tail, don't be afraid to reduce your flap deflection in order to improve your turn rate, and thus out turn your opponent.
Having said that, few things in life are cut and dry, and even that wisdom isn't always safe. It all depends on the aircraft. For example, take a look at the diagram for the A6M2 shown below:
(Image removed from quote.)
You will see that this case is very different from the previous one. Instead of the flaps producing an increase in the sustained turn rate as it did in with the F4U1D, you now notice that as the flaps are deflected the turn radius tightens up as expected, but now the sustained turn rate drops also. You can see that while there is a significant drop in sustained turn rate for the first and second notch of flap deflection, the second, third and fourth positions all have very similar turn rates.
The conclusion you can draw from this is that for this aircraft, if you want to maximise your turn rate, don't use your flaps at all. There is no sweet spot as there was with the F4U1D. Also, if you feel the need to deflect the flaps by two notches, you might as well go all the way, because you will get a tighter turn radius and your sustained turn rate won't diminish any farther than it already has. However, in this case the turn radii are small and the reduction in radius at full flaps is significant and that introduces another complication.
Most of us learn fairly quickly that the right thing to do in a nose to tail turn would be to optimise turn rate, however because the circles are so small in this example, there is a danger that a player who drops full flaps may be able to pull his nose inside his opponent's turn for a shot across the circle. If the shot succeeds, the energy sacrificed will be worthwhile, but if you don't make the shot, at worst it may very quickly prove fatal, or at best the energy lost in the attempt will haunt you throughout the remainder of the fight. That's why some players will deliberately offer the prospect of a shot in the hope that their opponent will go full flaps and give up all their energy for a first shot opportunity.
On the other hand, getting slow quickly and using full flaps is a strategy that can be an effective way to get quick kills if you always take the fight one circle, in a scissors type engagement, in which case full flaps is almost always the right thing to do. It can be so effective against weaker players that it is easy to get locked into that way of fighting. The catch is that a good player can force the fight back to a nose to tail turn, and if they are good at optimising aircraft performance in that that situation, and if they have a proper understanding of the relationship between angles and energy, the fight can become very difficult for the player stuck at full flaps with a one circle fixation. The longer such a player allows themselves to remain in that situation, the more they continue to lose angles and energy until they become entirely defensive.
The bottom line is that good players develop a feel for when and how to use flaps so that they can maximise aircraft performance for the situation they are in. They simply know where the sweet spot is for their particular ride. It takes hundreds of hours of top quality fighting to develop the skills needed to excel in this, so my advice to anyone who hasn't figured it out yet is this:
Forget about trying to survive, speed is life, but you won't learn as much that way. Get stuck in at every opportunity, seek out tough fights because quality experience produces accelerated learning and adrenaline packed fun! That is the best way to make rapid progress, because as other players appreciate your willingness to engage and have fun, the better ones will be equally willing to help, its a win win situation.
Hope that helps...
Badboy
