Badboy's E-M Diagrams

[PJ_Godzilla]

Badboy, you've raised the specter of something I was thinking about just yesterday. EM works in the horizontal plane where grav force is constant. Yet we all know that there are two (principal) planes in which to maneuver. However, because, in the vertical plane, the grav force is constant but the lift vector is rotating from aligned to grav to opposite of grav and alt is variable as well, the analysis is trickier. Have you seen/has anyone done any solid analysis work on minimal loop circles?

It seems to me that you'd actually have a stretched (biased - larger radius at bottom where the speeds are higher) ellipse on the vertical and that, while it wouldn't make sense to talk about "turn rate" (because variable throughout maneuver) it might make sense to talk about angular displacement over a given time window. Again, you'd have at issue whether the loop was energy neutral or an energy sink, since you could probably tighten the top and bottom radii by converting speed. This'd clearly be an integral in time of the rate of angular displacement expressed in time-dependent expressions, itself dependent on the same  physicals you see in horizontal, just recast to allow them to be f(t).

Otherwise, thanks for this analysis. The thing that I'm sturck by about this is that it's a race to the bottom. They're both going to want to start at corner but invariably will end up low and slow and popping flaps, at least if the knife-fight lasts that long and stays horizontal. OTOH, both have solid accel and climb rates - and somebody might do something dumb.

[Drano]

Then, your last statement appears to contradict your earlier assertion - so you leave me a bit baffled.

You're right I did. That's what happens before coffee. 

[Owlblink]

Thanks Badboy!   

I too have a question regarding the vertical eliment, and not sure exacly how the physics plays out so I'm hoping someone here can aid me in properly visualizing this.

If I'm in my 109K and coming down from a vertical, and the enemy plane climbs up into my dive/decent, when (or at what speed) should I pull back on my elevaters and return going vertical? I know that gravity is working against me getting my nose back up above the horizon, so I'm wondering how fast/slow I would need to be in order to reduce the time it takes for me to get my nose back up. Would it be closer to the max corner velocity (as in turning just before I reach it, knowing that I accelerate in my decent) or do I want to turn back up into the vertical at a much slower speed?

OR, is the answer "as soon as possible" in order to reduce the chanse of the enemy reversing onto my six to gain angles? I hope my hypothetical situation is written in a mannor that makes some sort of sense.

[Badboy]

Badboy, can you say a few words on the trend impact of alt?

You can see the general trend by looking at a set of diagrams I did some time ago for a Battle of Britain Scenario. This set shows the performance in 10,000ft increments.









You can see that typically, the turning ability of all the aircraft is degraded at high altitudes in terms of their turn rates and radii.

You notice in the last diagram these aircraft hit their top speed at that altitude before they can reach their 6g corner velocity, in effect they can't pull enough G so their corner velocity is defined by their lift limit. The Bf110c for example can just make 5g at top speed, and can only sustain about 1.3g. In general their sustained turning ability will depend on engine performance at altitude.

Usual disclaimer... those diagrams are dated, and while the trends are typical, they may no longer be accurate representations of current AH aircraft.   

Badboy

[Ardy123]

Do you guys notice something, the people asking about how to deal with spit16s in a k4?

Look at the sustained turn rate and at what speed

[Ardy123]

Hint....

The corner velocity and the sustained are very similar in both the k4 and the spit16 but...

1) How fast can you change 'e' states in each ride?
2) How many notches of flaps do you have?
3) How fast can you go before you get a notch (or two) out?
4) Is there a speed at which the k4's dps is greater than the spit 16s?

[PJ_Godzilla]

Do you guys notice something, the people asking about how to deal with spit16s in a k4?

Look at the sustained turn rate and at what speed

First, it looks to me like the k4 will own the Spit at 300 plus, since this looks to be roughly where it's sustained turn rate outstrips the rate of the Spit. The K4 is definitely the "energy" fighter, the Spit the angles fighter.

 As for your hint, I'm not sure which has better energy income... certainly the K4 has huge mass-specific power but so does the XVI, which is well known for accel. As for the flaps, I think it's still a losing bet for the K4. They won't even pop until 195, and that's just the first notch. OTOH, it also looks like the Spit's  first notch won't come out 'til about 180. So, perhaps you could exploit that window for a quick turn 'til decel/pop a notch/maneuver/fire/split using the DB's massive power? My only question w/r this "theory" - is what kind of instant or sustained turn perf you can get with one notch on a K-4 - because clean at that speed, the Spitty owns at least a couple of deg/sec sustained or instantaneous turn rate advantage.

[FLS]

I have a few comments.

A sustained turn difference of 4 dps is not close.

Note the differences in turn radius.

A Spit at 300mph isn't going to stay at 3 Gs in a turn fight with a K4 when it can increase it's turn rate and decrease it's radius by pulling harder and slowing down.

[Ardy123]

Ok....

So here is the deal.....

1)Most of the time, a 109 can LOOSE its energy faster than a spit, which means you can get to corner faster.

2) Once there strive for the snap shot. Also, a spit only has 1 notch of flaps, full or none, which means in a 109, drop one notch, at almost 200, force the spit to drop flaps (all flaps as he only has one notch), then climb out or enter a steep vert rolling scissors eeking out every drop of e you have. The act of forcing him to drop full flaps, will burn his e much faster than you, giving you a noticeable speed difference. Oh and look, a k4 can get back to corner very fast from 195 to 230 in no time, where the spit has prob will have to go from 150 - 230ish. Now, some of the best pilots will just lag turn in the spit, but most will pull as hard as they can with everything they got as they put faith in relying on their turn abilities.

3) If fight gets slow and your not on top, dive out and repeat.

4) Lastly, spits dive better than k4s, so get into a nose down vert scissors, (drop full flaps, cut throttle), chances are, the spit will not do everything and overshoot as he accelerates better and retains e better nose down. (Poor e retention is a double edged sword).

Next time in the ma, do this... as a test... (this is not a good strategy as a acm but it proves my point)

1) Get a spit on your 6 and dive with him following... ( make sure he is close, within ~400, so once you see him drop your nose down steeply, full wep, etc)
2) Once at 300 ( hopfully before he shots you), level out and cut throttle, and do as hard as you can, turn to the left. Also, make sure to throw some rudder in there to keep the 'ball' in the center.
3) watch him overshoot as he trys to follow you in the turn.

Why this works: 109 retains e much worse than a spit, so get to corner faster and your turn is tighter.

A Spit at 300mph isn't going to stay at 3 Gs in a turn fight with a K4 when it can increase it's turn rate and decrease it's radius by pulling harder and slowing down.

And when he blows his 'e' to pull for lead, go for 'e' and climb!... you have the same climb rate as him (if not a tad better) and from the spits perspective, you will disappear! (as he has pulled lead for the shot, so you under his nose, in which case you roll and pull up, and he wont see you do it)

I'm sure FLS can elaborate more on this.

[FLS]

You can describe any outcome you like. 

Those EM diagrams show you that you don't want an even fight on the deck in a K4 against a Spit 16.

I expect the better pilot will usually win in any case. 

[Badboy]

Badboy, would it be possible to make diagrams for the ww1 planes?

Hi Urchin

Here is what comes out of the BootStrap Calculater for the WWI aircraft, all at Sea Level with 25% fuel. The diagrams show the turn radius and turn rate graphically so you can picture the geometry of a fight between the aircraft.





Hope that helps...

Badboy

[FLS]

Thanks Badboy. The F2b is surprisingly good against the DVII.

[Ardy123]

You can describe any outcome you like. 

Those EM diagrams show you that you don't want an even fight on the deck in a K4 against a Spit 16.

I expect the better pilot will usually win in any case. 

Agreed equal pilots in a turn fight, spit 16 wins. K4 is much faster so k4 pilot could bnz the spit to death. Either way, my point was that because the spit has a tighter and more dps sustained turn, probably means that it doesn't burn as much e making an instantaneous turn and thus recognizing this and using it against the spit is the key.

[PJ_Godzilla]

Ok....

1) Get a spit on your 6 and dive with him following... ( make sure he is close, within ~400, so once you see him drop your nose down steeply, full wep, etc)
2) Once at 300 ( hopfully before he shots you), level out and cut throttle, and do as hard as you can, turn to the left. Also, make sure to throw some rudder in there to keep the 'ball' in the center.
3) watch him overshoot as he trys to follow you in the turn.

And when he blows his 'e' to pull for lead, go for 'e' and climb!... you have the same climb rate as him (if not a tad better) and from the spits perspective, you will disappear! (as he has pulled lead for the shot, so you under his nose, in which case you roll and pull up, and he wont see you do it)

I'm sure FLS can elaborate more on this.

I like either of these. I have to admit, most of the time I just avoid Spits in either G-14 or K-4, beyond making the occasional high-speed firing pass. It's very bad to get caught low and slow by one. The tricky thing with both of these tactics, as with the rope so frequently useful against poorer-climbing AC than Mr. Spitty, is that they start from a position in which you can get shot. However, the tight turn folowed by roll-to-level and pulling up strikes me as particularly good since it puts you in a position in which you can use roll to put your lift vector back onto the Spitty from above, possibly getting, from there, a snap opportunity. I'm assuming that, at low enough alt, I can do the same in a G-14. Looking at the comparison, I'd say a similar tack will work, assuming I'm sans gondolas (more and more these days).

I guess I'd also think that the roll-to inverted and dive away might be a decent way to disengage, though the drooling easy-mode jockey will doubtless come around and still have some speed with which to follow. I always like the K-4's extension capabilities and even the G-14 ain't bad at it. That's probably enough for Mr. Spitty pilot to say, "duuuuh I got to yank da stick... duuuuuuh."

I've learned to love the Zero in AvA this week but, let's face it, this constant meat-pulling thing doesn't require much upstairs. Spitty is therefore sort of like a cheap hooker or an airline seat - any smecking, leering idiot can enjoy one at a low price. That's not to say there aren't some really good Spitty jocks. 

Also, I think Badboy has just documented a big part of the reason why the LW's switch to bombing London was so disastrous in the BoB. In the hands of average pilots, the LW set is overmatched.

[Urchin]

Badboy, thanks!

What information do the e-m diagrams show that those turning circles don't? I'm curious if there is some tool that may help me identify an area that the camel has an advantage over the dr1. Thanks again Badboy.