Sprial Climb question

[dtrip61]

As far as making "cheat sheets" for each probable plane matchup....you're getting way too complicated.  It's not like it was in RL where there was a limited number of threat airframes you could reasonably expect to encounter.  Keep it as simple as possible.

Know which fight you are going to fight BEFORE the first merge.  You can do that by estimating your E state versus the bandit.  Based on E states and a general understanding of your turn, climb, and acceleration rates versus the bandit's you're going to immediately go for an angles fight or an energy fight while always trying to maintain an escape route.  If you're caught low and slow you're obviously more limited in your options.  I fly the hogs pretty exclusively which makes the equation even simpler since it's "limited" at best in acceleration and climb (especially the birdcage -1) so if I'm caught at an E disadvantage and the opponent's first move is an energy retaining merge then I know I'm in deep doo.  Most every plane in the arena can BnZ a low slow hog at will.  My only chance is to show enough leg to bait them into the only fight I have a chance of fighting and that's a ragged edge down and dirty turn fight full of plenty of flap work and a bunch of high and low yo yo's and some serious foot stomping rudder and throttle work (the hog is one VERY busy plane to fly well in a slow fight).

KISS principle.  Co E --> Can I out turn him or can he out accelerate/out climb me?  Yes = Angles fight.  No = E fight.  You'll get a feel for blending the two fights together based on how the bandit reacts to your maneuvering.

-dtrip

[PJ_Godzilla]

What factors can I look at when comparing planes to see if a spiral climb will be effective?  I was thinking it's a combination of the climb rate and acceleration that keeps you above the other plane in a spiral climb.  

I know the spiral climb is not the end all be all ACM maneuver but it sure seems to be one of the most important to perfect.  

Thanks,
Pollux

Actually, you migh tlike to look at Badboy's tutorial on the E-M diagram. http://www.simhq.com/_air/air_011a.html

Let me attempt to paraphrase If you pull g above your sustained turn limit at whatever point you are on the speed continuum, you will decelerate at constant alt. In order to maintain speed, however, you might trade alt. So, these birds you're flying against likely just don't have as high a sustained turn line as you and have to trade energy for the g they're pulling - and they do this by giving up their alt to maintain their speed at the g-loading dictated by the knife-fight they're in.

In this case, it'll be instructive to, for your desired comparative purposes, go back to the sustained turn limit equation - wing loading (lower is better)  and bank angle (max - higher is better) feature prominently here. Wingloading is clear enough and the Spit has a nice low one . Max bank is dictated by power loading.

In short, low wingloading and high power loading make for a bad-aced fighter - at least in the turn and burn or angles game. If you follow Badby's E-M logic, though, the right hand side of the e-m is the plac ein which a higher wingloaded a/c can make up for his sustained turn deficit - another topic.

[dtango]

Actually, you migh tlike to look at Badboy's tutorial on the E-M diagram. http://www.simhq.com/_air/air_011a.html

This should be required reading for all aspiring virtual ace dweebs on the concept of rate of "N-R-G" change, what controls it, and how it impacts an airplane's "maneuver-ability" including spiral climbs.

....In short, low wingloading and high power loading make for a bad-aced fighter.

QFT 



....


My penny's worth on Air Combat Principia:

1) There are no absolutes in air combat, it's all relative.
2) You can't defy aerodynamics, nature always wins.
3) There is no spoon (i.e., if your thinking is limited, your dogfighting will be limited by your thinking).

[PJ_Godzilla]

DTango - I love that photo. It's a perfect example of the most counterinituitive aspect of this thing - how a poorer-turning but faster a/c can get 6 on a better turner.

[dtango]

DTango - I love that photo. It's a perfect example of the most counterinituitive aspect of this thing - how a poorer-turning but faster a/c can get 6 on a better turner.

   that wasn't quite my intent with the pic...but yeah, your comment illustrates pricinpia #1 and #3!

BTW the pic is the F-16 demonstrating it's better turn rate and radius vs. the F-4E.

[PJ_Godzilla]

One thing I forgot to add, and that people might think about a little, was the impact of drag. Recall that Cl appears in the denom of that sustained turn equation. It'll be the Cl that delivers enough lift at some extreme bank theta max such that you lose no alt. This is where relative drag plays in to making or breaking the fighter. You can express, of course, the Cl as a function of the Cd0 and Cd, right? I.e., Cl = ((Cd-Cd0)/k)^.5. and THAT's ASSUMING WE'RE IN THE LINEAR CD VS CL REGION...

Since sustained turn will go up as Cl required decreases, we want to minimize (Cd-Cd0)/k
Remember that k = 1/(pi*AR*e) so that the denom will grow with AR. Leaving that aside since intuitively pleasing anyway, we can go on. Since Cd0 is a constant and Cd is always going to be greater than Cd0 at positive lift, we can say we want minimal induced drag for the necessary lift, yes? And this is why a Spitfire makes a better fighter than a barn door if both have the same wingloading and powerloading.   I.e. you want something with a very healthy d(Cl)/d(Cd) as well as the two aforementioned attributes.

I'd welcome feedback on this since I kind of did it out of my head and could be all wet - but it's making sense and I'm lucid, at least right now.

[PJ_Godzilla]

 that wasn't quite my intent with the pic...but yeah, your comment illustrates pricinpia #1 and #3!

BTW the pic is the F-16 demonstrating it's better turn rate and radius vs. the F-4E.

In which case, as the F-4e burns some e to get that last bit of angle, the F-16 will be able to point the nose straight up and accelerate vertically out of plane, immie, and come right back down on the now-bled f-4e stuck double-ugly pig.

It's really no contest. the 16 has it all over the Phantom except for maybe top speed. I'm sure the structural limit line on the 16 is probably better anyway so even in high-speed maneuvers probably the 16 kills it.

[dtango]

One thing I forgot to add, and that people might think about a little, was the impact of drag.... 

You dare bring maths into this??? (I know, kettle / pot thingy going on here).  This is why I love this equation:



It's the E=mc^2 of dogfighting.  So magnificently elegant, explains how the world works, but deceptively sophisticated in a brain blowing sort of way.  Many a virtual pilot has gone down in flames flummoxed by this enigma (how did that Spit catch me?? where did it get all it's E??? etc.).  As you elude to that "D" in the equation in itself is a tricky little devil.

To add to your discussion assuming a situation of sustained maneuvering when total drag in maneuvering exactly cancels out thrust (when Ps=0), after monkeying around with the equations turn-rate can be expressed as:



(turn radius is just V^2/numerator of the turn rate equation). 

This confirms your view that the healthier the Cl/Cd for a maneuvering airplane, the better the Ps margin and thus the better the fighter.

[ink]

You dare bring maths into this??? (I know, kettle / pot thingy going on here).  This is why I love this equation:

(Image removed from quote.)

It's the E=mc^2 of dogfighting.  So magnificently elegant, explains how the world works, but deceptively sophisticated in a brain blowing sort of way.  Many a virtual pilot has gone down in flames flummoxed by this enigma (how did that Spit catch me?? where did it get all it's E??? etc.).  As you elude to that "D" in the equation in itself is a tricky little devil.

To add to your discussion assuming a situation of sustained maneuvering when total drag in maneuvering exactly cancels out thrust (when Ps=0), after monkeying around with the equations turn-rate can be expressed as:

(Image removed from quote.)

(turn radius is just V^2/numerator of the turn rate equation). 

This confirms your view that the healthier the Cl/Cd for a maneuvering airplane, the better the Ps margin and thus the better the fighter.

please for the sake of all humanity stop.....just stop....you are hurting my head

[PJ_Godzilla]

You dare bring maths into this??? (I know, kettle / pot thingy going on here).  This is why I love this equation:

(Image removed from quote.)

It's the E=mc^2 of dogfighting.  So magnificently elegant, explains how the world works, but deceptively sophisticated in a brain blowing sort of way.  Many a virtual pilot has gone down in flames flummoxed by this enigma (how did that Spit catch me?? where did it get all it's E??? etc.).  As you elude to that "D" in the equation in itself is a tricky little devil.

To add to your discussion assuming a situation of sustained maneuvering when total drag in maneuvering exactly cancels out thrust (when Ps=0), after monkeying around with the equations turn-rate can be expressed as:

(Image removed from quote.)

(turn radius is just V^2/numerator of the turn rate equation). 

This confirms your view that the healthier the Cl/Cd for a maneuvering airplane, the better the Ps margin and thus the better the fighter.

This confirms my view that bbs desperately need another forum entitled the Tango/Godzilla admiration society. Thanks for that more rigorous path.

[dtango]

please for the sake of all humanity stop.....just stop....you are hurting my head

As the Dr. says, "take two tylenol and then call me."  'Course truth be known this stuff makes my head hurt too.  This drawing should help us all:

[dtango]

This confirms my view that bbs desperately need another forum entitled the Tango/Godzilla admiration society.

   

Dear God, No.  It probably already exists in some sick alternate universe in which case doing that here would create a paradox collapsing the whole multiverse along with it.  I don't want that on my head!  It hurts enough already.