Ta-152 vs Spit 14

[Crumpp]

Crumpp, you completly confuse climb angle and AoA, which has nothing to do with each other.

No I haven't bozon.  I very well know the difference.  

http://www.av8n.com/how/htm/aoa.html#fig-incidence


Some people think:

You may have heard the assertion that “Power plus Attitude equals Performance”. Well, that assertion is not quite right, and has caused all sorts of unnecessary confusion.

http://www.av8n.com/how/htm/aoa.html#sec-power-attitude-performance

Crumpp

[Crumpp]

However, caught up in a tight one with a late war Spitty or Mustang could still leave it with little option.
If the 190 would fight a Spit IXbooster for instance, it might find itself at stall, 5K, with no possibility to get away, be it upwards or downwards. With a turning circle of 200 metres or so, the max distance between circling dogfighters would be 300 yards. the 190 hits the climb. the Spitty is 300 metres behind on it's dead 6. The 190 is pulling away at 20 km/hr.

Angus M8,

Don't forget the first part of ANY climb above Best Climb Speed is the zoom climb.  Traveling the same speed the FW-190 will handily out zoom the spit.  

So in the initial part of the any climb the rate of extension will heavily favor the 190.  Then if the climb angle is at best climb angle or below for the 190 it will slow down to best climb.  If the Spitfire is directly following still, then it will left at the difference between best climb speeds.

Some other tiny details that are important to that scenario too.  
Roll rate - It takes the FW-190  of the time to roll out of the turning circle.  At 400mph it takes a 190A .78 seconds to roll 45 degrees.  It takes a Spit 1.85 seconds at that speed to roll 45 degrees.  So the 190 has a head start out of the circle.  At that speed the FW-190 travels 170 meters per second.  That is a significant head start.  At Low Speeds the disparity is even more dramatic between the roll rates.  Factor in the stick forces and the pilots ability to apply them, as is measured in the Roll Rate Report, and it is easy to see why Spit pilots were in awe of the 190's roll rate.  BTW M8, Do Spitfires normally have metal covered ailerons? They make a big deal about it in the report.  Seems like an experimental thing.

Level/Dive Acceleration - Just as Johnson used his P47's strengths.  A very shallow dive of a couple of degrees to gain an even larger zoom parity.

So until the Spit XIV arrives, the Spitfire was an equal to the FW-190A.

Crumpp

[Angus]

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Crumpp, you completly confuse climb angle and AoA, which has nothing to do with each other.
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"

How so? I think he has it right. Well, A of A for the aircraft = Angle of climb, at least that's how I understand his meaning.
Of course total A of A is always a tad more than the angle of climb, just a question of understanding his point.

[bozon]

climb angle is set by the ratio of forward speed and climb speed (what you see on the air-speed and rate-of-climb indicators, and yes, there is an insignificant correction for AoA).
It is not how high the nose is pointing over the horison.

Spits are very good at climbing angle since their best climbing speed is low and they have a good climb rate at that speed.
American pilots in Korea belived the mig 15 had superb climb properties. It turned out the Sabres actually out climbed the mig but at a much shallower angle (better ROC but at higher speed), so they couldn't follow the migs up in a sustained manuver (nothing to do with zoom).

Don't forget the first part of ANY climb above Best Climb Speed is the zoom climb.

not true. perhaps you mean the sustained climb speed at that climb angle (see above).

Bozon

[Nashwan]

Crumpp, I think this thead is beyond saving, may as well continue it here.

Nobody is saying that the Spit Mk IX did not have a faster climb rate. That is a fact.

Yes, I think we can both agree on that.

The Spit does have a much slower best climb speed. That is a fact.

I think we can both accept that as well, although "much" might need some defining.

The FW-190A8's best climb speed is around 182 mph. The Spit IX LF is 170 at best dropping quickly with altitude.

The 190's will drop with altitude too.

But I'll happily agree the 190 climbed at 182, the Spit at 170.

If a spit points it's nose DIRECTLY at the FW-190 it will be out climbed because it cannot maintain the same VSI at the same AOA.

Again, that's like saying the Spit couldn't point it's nose at the 109 in level flight because the AOA will be wrong.

It will take very minor adjustments to get the AOA right for the 190 to be in the Spit's sights.

If the spit cannot add any more power to the climb then he will pay the price in Airspeed. The TOP of the any A/C's power curve IS its best climb speed. That means the Spit wants to be going 170mph in the climb! The point where the maximum angle of climb and the top of the power curve meet is the best climb rate!

Yes. But we've already established that the Spit's climb rate is much higher than the 190's.

The Spit doesn't need to maintain it's maximum climb rate to keep up with the 190.

If the Spit climbs at say 4700 ft/min at 170 IAS, then it will climb more slowly at 182 IAS, but it will still climb. What you need to show is that the gain of 12 mph in it's speed will reduce it's climb rate to the same level as the 190's.

Remeber, any plane that's flying at less than it's max speed can still climb. A spit IX can still climb at some altitudes when it's doing 400 mph, although very slowly.

Any altitude where the Spit is almost as fast, or faster, than the 190 and the Spit should be able to climb at the same rate and speed as the 190, and even at altitudes where the Spit's speed is some way below the 190's.

Because the power curve is flat at the top, he will quickly find himself climbing at a shallower angle at 170mph.

We know that the 190 climbs at a shallower angle than the Spit. It has too, because at a higher speed and the same angle it will climb better, and we know it actually climbs much worse.

So the 190's best climb rate is achieved at a much shallower angle than the Spit's.

So we have no gun solution and at the same VSI and the FW-190 is moving faster along the same vector. The spit gets out climbed.

But you do have a guns solution. You have the same guns solution the Spit would have on a 190 in level flight.

You will always need an AoA adjustment to bring a target under your guns. The tiny AoA adjustment will be lost in the far larger adjusments of aim needed.

Only way to reach the same VSI and angle is that both A/C are at the same point on the power curve.

Yes. Of course, if one has more power, he can throttle back to get on the same  vsi/angle climb.

When the FW-190 received more thrust it's angle of climb increased BUT it's Best climb speed stayed the same.

Yes. Best climb speed is achieved when you have minimum drag, and that's achieved at a point where you have the minimum induced drag and profile drag.

Going slower increases induced drag,  profile drag reduces but not as much as induced drag increase. NEt effect is an increase in drag, more power used, less available for climbing.

Going faster reduces induced drag, but increases profile drag, net effect less power available for climbing.

Now we know that at 170 mph, the Spit can easily outclimb the 190. That means that at 182, the Spit will be using more power, and will have less available for climbing.

But that doesn't mean that the reduced climb rate for the Spit will not still be as high, or higher, than the 190's.

These number don`t include C-3 boost, that was added to the A-5 and boosted the ROC to 4600 fpm, or about 15%, as per UK sources.

Any chance of a source for that?

No they don't. That is why Aeronautical engineers have always been willing to add some weight and power to fighter designs.

Adding weight and power is helpful, but the weight is an unwanted side effect of adding more power, not a goal.

If you can add the power without the weight, that is preferable.

You seem to be suggesting that the Spit XIV is superior to a 25 lbs Spit IX, even at low altitude, because it has more weight.

BTW M8, Do Spitfires normally have metal covered ailerons? They make a big deal about it in the report. Seems like an experimental thing.

Metal ailerons were introduced on the Spit V, and used in all subsequent marks (that I'm aware of)

Later mark Spits also had stiffer wings which would have gone some way to improving roll rate, as iirc the V suffered a lot from wing twisting reducing the effectiveness of the ailerons at high speed.

So until the Spit XIV arrives, the Spitfire was an equal to the FW-190A.

I'd go with that as well, but excluding the use of 150 octane fuel. At 25 lbs, the Spit was superior to the 190 A series.

[Crumpp]

Ok,

There seems to be some confusion as to what are A/C "numbers" mean.

Here:

Suppose we wish to achieve the best rate of climb:  

 A) You could try to control the airplane by reference to the “rate of climb” number shown on the vertical speed indicator. This is not recommended!
B) It would be better to maintain VY, the nominal best-rate-of-climb speed, as shown on the airspeed indicator, and accept whatever rate of climb results. This is almost exactly the right idea.
C) It would be even better to realize that the best rate of climb is achieved at a particular angle of attack. In particular, if the airplane is lightly loaded compared to what was anticipated in the handbook, the best rate of climb will be achieved at a lower speed than is reflected in the handbook’s VY value.
This is not an isolated example. Many of the airplane’s critical performance numbers are really angle of attack numbers:
  Þ  The stall occurs at a particular angle of attack.
  Þ  The smallest power-off descent rate occurs at a particular angle of attack.
  Þ  The best power-off glide ratio occurs at a particular angle of attack.
  Þ  The recommended “approach speed” is really an angle of attack recommendation.
  Þ  The best rate of climb occurs at a particular angle of attack.
  Þ  The best angle of climb occurs at a particular angle of attack.1, 2

http://www.av8n.com/how/htm/aoa.html

An Airplane achieves it's best performance when flown by it's numbers.  It makes sense to non-pilots that "Power plus attitude = performance"  but that is not the case.

Lets examine the power curve:

Life would be simpler if manufacturers would explicitly show the power curve somewhere in the POH, but they don’t. You have to figure it out for yourself. Fortunately, the general shape of the power curve is more-or-less9 the same for all airplanes, so the concepts discussed here are very widely applicable.

http://www.av8n.com/how/htm/energy.html#fig-power-curve-regimes

That means all Airplanes have a FLAT power curve.  The TOP of that curve is the BEST CLIMB Speed:  

Let’s start by comparing figure 7.5 to figure 7.6. As shown in figure 7.5, the highest point on the power curve represents the best rate of climb. The corresponding airspeed is denoted VY.

http://www.av8n.com/how/htm/power.html#sec-best-angle-climb

Not lets look at BEST CLIMB ANGLE:

We see that the power curve is rather flat on top. That means that if you fly a couple of knots faster than VY, your rate of climb will hardly be affected at all. You will reach your destination a percent or two sooner, so this sort of “cruise climb” is generally a sensible thing to do.

http://www.av8n.com/how/htm/power.html#sec-best-angle-climb

But don’t get carried away; the power curve tells you that if you slow down enough, you will degrade the climb performance to the point where further reductions in airspeed don’t pay.

Both A/C can do this and the 190 is faster.

Since the top of the Power Curve is flat there is a wide variety of angles the plane can fly that have No effect on Airspeed.  Your still going 170 mph at a shallower angle.

Now any climb which is started ABOVE Best Climb speed is a ZOOM CLIMB which ends, provided the Angle of attack is not ABOVE best climb angle in a sustained climb at Best Climbing speed. That is the point of equilibrium the plane wants to be at to balance the forces of flight.  

If the 190A and a Spit begin a climb at the same speed:

1.  In the initial zoom the 190 will leave the spit.

            a.  The 190 has more mass
            b.  The 190 has less drag

2.  At the end of the zoom, both A/C will slow to Best Climb Speed.

             a.  The 190's Best climb speed is faster
             b.  IF the spit maintains the 190's shallower angle he will be left behind.

I will continue later.  Got a family function to go to now.

[Angus]

Crumpp:
Looking at the fact that the best merlin Spits climb up too 1000 fpm better than the 190 A series while the 190 climbs 12 mph faster, those spits MUST be able to follow the 190. Why? well, the Spitty is gaining upwards altitude at it's best climb rate at the same rate as the 190 is gaining forward distance.
Otherwise, the Spitfire would always be able to outclimb behind, level out and catch the 190 while still climbing.
Zooming is another issue, and will only make a difference until both aircraft are again at climbing speed. Zooming will of course help with departure.
Nashwan, IMHO, at some alt bands, only the best Merlin spits could compete with the 190's on any level (190 outrolling always). The death and dread being the IX LF and VIII with 25+ boost.
I'd say that the VIII +25 would indeed rank as the best dogfighter AND multi-purpose fighter of WW2

[GRUNHERZ]

I think FW190 series development was very very poor during the war. Spits and did much better.

FW was ready to produce a 450mph+ DB603 engined, 5 cannon 2 mg armed 190 by late 1942 but the autorities didnt want any part of that so it wasnt for lack of trying.  Conclusion: Thankfully Teh nazi R dumb..

[Nashwan]

I've drawn a quick (and very dirty) graph of what I'm trying to say.

We know the climb rate of these aircraft at 2 speeds. The best climb speed, ie 170 mph for the Spit, 182 mph for the 190, and their maximum speeds.

Obviously, at maximum speed climb rate will be zero, as all the available power is going to maintain forward momentum, and none is available to climb.

Note that this graph assumes a linear fall off of climb rate with speed, which I doubt is accurate.  Someone like HoHun, GWShaw etc would probably be able to do a much better job.

However, the purpose of this is just to explain a point I'm having difficulty conveying with words.



Edit: The vertical scale is climb rate in ft/min, the horizontal speed in mph. All values are at sea level. I've used Isegrim's figures for the 190 (If I understand them correctly)

As you can see, climb rate drops with a speed increase past best climbing speed, but the Spit has a climb rate advantage and can afford to fly outside it's best climb speed and still exceed the 190s rate of climb.

Now any climb which is started ABOVE Best Climb speed is a ZOOM CLIMB which ends, provided the Angle of attack is not ABOVE best climb angle in a sustained climb at Best Climbing speed. That is the point of equilibrium the plane wants to be at to balance the forces of flight.

No, the excess speed will only drop off if you keep the angle high enough. Any plane can climb at any speed up to it's maximum speed, because at anything less than maximum speed it still has excess power.

You can climb at 300 mph at sea level in the Spit, just at a very shallow angle. You can hold a 300 mph climb in the Spit all the way up to 30,000ft or more. (TAS)

Only if you keep the angle too high will the climb speed begin to drop.

2. At the end of the zoom, both A/C will slow to Best Climb Speed.

Only if the angle is great enough. If the Spit tries to maintain the same angle at 200 mph that it can maintain at 170, speed will drop, but you can raise and lower climb speed by increasing or lowering the angle.

Try climbing in AH without using auto climb. Watch the ASI, and try to keep 170 IAS. You puch the stick forward when the speed drops below 170, pull back when it goes above 170.

You are adjusting the climb angle to keep a desired speed.

Now do the same at 180, or 200, or even 300 mph. You can maintain a climb at any speed below maximum simply by adjusting the angle.

a. The 190's Best climb speed is faster
b. IF the spit maintains the 190's shallower angle he will be left behind.

No, see the graph above. Obviously if the climb rates were identical to begin with, the Spit would start to fall behind the 190 at anything other than it's optimum climb. But if the Spit has a large initial advantage, it can afford to climb at less than optimum speed and still be better than the 190.

[Crumpp]

Nashwan, bro.

I am not trying to sound like an arrogant know it all, so please don't think I am in this reply.  

No, the excess speed will only drop off if you keep the angle high enough. Any plane can climb at any speed up to it's maximum speed, because at anything less than maximum speed it still has excess power.

Look at the Power Curve again and see what happens as soon as you raise the angle of attack above Zero.
The speed begins to drop.  When your zoom climb is finished, your plane drops to sustained climb speed.  Your speed will balance out along that power curve.  Angle for angle the 190 is faster.  The end of the power curve is level flight.

But ONLY at angles below the 190's Best Climb angle.

Obviously, at maximum speed climb rate will be zero, as all the available power is going to maintain forward momentum, and none is available to climb.

Yes because the end of the power curve is level flight.

Note that this graph assumes a linear fall off of climb rate with speed, which I doubt is accurate. Someone like HoHun, GWShaw etc would probably be able to do a much better job.

Not sure exactly what you are showing with this chart, bro.  If you are trying to say the Spitfire had a large enough angle advantage it could directly follow the spit it did not.  It seems that way but when you understand the physics it could not catch it just because it's angle was better by following it directly.

 I will say though the light bulb came on with this.  I am not about to say that at high altitudes where the Spitfire performs its best and the 190 it's worst, that a Spitfire could not directly follow a 190.  As long as the 190's best climb speed is faster.  When it becomes the same then the Spitfire can directly follow.
Here is what the angle advantage will get the Spitfire:

Otherwise, the Spitfire would always be able to outclimb behind, level out and catch the 190 while still climbing.

Angus, bro, that is exactly what will happen IF the spit pilot abandons the direct chase and goes for his best angle of climb.
At that point a smart 190 pilot will level out and gain speed.
The Spitfire will end up above the 190 with more horizontal separation.

You can climb at 300 mph at sea level in the Spit, just at a very shallow angle. You can hold a 300 mph climb in the Spit all the way up to 30,000ft or more. (TAS)

And the reverse is true for the 190.  Remember that degree of angle FOR degree of angle the 190 moves closer to its rent free zone in the shallow climb than the Spitfire.  The Spitfires angle is steeper but is power curve height is much lower.

You are adjusting the climb angle to keep a desired speed.

Only until your angle reaches the top of the power curve which is flat.  From there you have a wide range of angle that produce little change in airspeed.

But if the Spit has a large initial advantage, it can afford to climb at less than optimum speed and still be better than the 190.

The Spit has a large climb advantage but due to his lower best climb speed he cannot point his nose directly at the 190.
If he does the 190 will soon be above him.  The Spitfire pilot has to point his nose up and use his greater climb angle advantage to out climb the 190.

Try climbing in AH without using auto climb. Watch the ASI, and try to keep 170 IAS. You puch the stick forward when the speed drops below 170, pull back when it goes above 170.

As it should.  Your moving along the power band AND your on the "mushing" end of the curve so speed increases are more dramatic.


http://www.av8n.com/how/htm/power.html#fig-vx

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After this we can discuss why the spitfire would not be able to get a gun solution in the climb without totally mushing his zoom.

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Nashwan, IMHO, at some alt bands, only the best Merlin spits could compete with the 190's on any level (190 outrolling always). The death and dread being the IX LF and VIII with 25+ boost.

Looking at the power/weight increases of both types I don't think the Spitfire Mk IX (+25) would be much different from the FW-190A3 vs Spitfire Merlin 61 (+12) tactical trials.

There was nothing to choose between either aircraft as regards turning circles at any height; whether on offensive or defensive manoeuvres neither could make any impression on the other. In rate of roll, however, the Spitfire IX was considerably better especially at low altitude. A number of full rolls through 360 degrees were timed by the same pilot flying each aircraft in turn and although quanitative tests are difficult to produce, it appeared that there was often more than 1.5 seconds superiority for the Mark IX over the Mark VIII. The Mark VIII feels fairly light on the ailerons but at high speeds it becomes very heavy, and so this new combination of extended wing and small aileron cannot be considered satisfactory.

http://www.fourthfightergroup.com/eagles/spit8tac.html

At altitude the Spit VIII would be nightmare but it's roll rate would severely hamper it.

Now the Spit XII clipped wing would be a tough fight for the 190 or for that matter any clipped wing spit would go along way towards reducing the 190's odds.  Wonder how the turning circle of the clipped wings is effected.

I think FW190 series development was very very poor during the war. Spits and did much better.

Actually, that is a myth, if you study both series the FW-190A gained less weight and just as much power over it's lifecycle as the Merlin Spits.
Remember the Luftwaffe had it's own enemy test flight.  The BMW-801 was "de-rated" while had a huge performance advantage.  It increased in power/weight just enough to keep its traditional advantages.  And like the Spit it received a much better armament package over it's lifecycle.  Both the Merlin 66 (+25) and the BMW 801D2 (1.58ata/1.65ata) are 2000hp (+) motors.  In fact they are almost exactly equal in power, just as the FW-190A3 and the Merlin 61(+12) Spit IX were in 1942.

Just as the RAF abandoned development of the Merlin Spits in favour of the Spit XIV, the Luftwaffe abandoned development of the 190A in favour of the Dora.

Now this only applies to jagd-einsatz's.  The FW-190A became the Luftwaffe's "jeep" of the air.  Comparing a jabo-einsatz's or a R7/R8 "Sturmjager" is apples and oranges to the Spit.

Crumpp

[Crumpp]

Looking at the power/weight increases of both types I don't think the Spitfire Mk IX (+25) would be much different from the FW-190A3 vs Spitfire Merlin 61 (+12) tactical trials.

I mean FW-190A8 (1.58ata/1.65ata) vs Merlin 66 (+25).

Crumpp