Spit 5

[Crumpp]

This number has nothing to do with my calculations. The only Cl value for the Fw 190 at 300km/h I had posted before Crumpp's post is Cl 1,451 at 3 g load. If converted from 3D to 2D ie downwash effect of aspect ratio 6,02 is removed then the Clo is 1,5715.

Just stop it Gripen.  Nobody is making anything up.

Anyone can run your numbers throught the formulas here:

http://www.grc.nasa.gov/WWW/K-12/airplane/downwash.html

You have already shown an understanding of aerodynamics that is not as complete as you present your knowledge to be.

The prudent man would just drop it.  I sent some more questions to the NASA engineer.  When the answers come back I will post them.

"It is better to keep you mouth shut and be thought a fool, than to open it and remove all doubt."

Guppy35,

While I do not doubt the sincerity of those pilots flying the Spitfire XII and I enjoyed reading it, it is like trying to gain performance insights from the fact Adi Glunz used to volunteer to fly the morning recon (2 ship element) flight over Dover in 1943 until it was stopped in 1944 so he could shoot down spits or the number of high scoring aces the type produced.

Here is an excellent book to read on this subject:

http://www.airpower.maxwell.af.mil/airchronicles/bookrev/spick.html

The Me-109 had a three year head start in combat over the FW-190 and was produced in much greater numbers.  Yet the FW-190 produced many top scoring Aces.

http://www.luftwaffe-experten.com/pilots_day/O_Kittel.html

http://www.luftwaffe-experten.com/pilots_day/W_Nowotny.html

http://www.luftwaffe-experten.com/pilots_day/E_Rudorffer.html

http://www.luftwaffe-experten.com/pilots_day/H-Bar.html

http://www.luftwaffe-experten.com/pilots_day/J_Brendel.html

These are just guys who flew mainly the FW-190 and scored OVER 100 victories in it.  It does not include names like Pips Priller and Adi Glunz.

Crumpp

[Crumpp]

I remember Johnny Johnsson mentioning this tactics. He flew a mission with Harris (the ace). This was the tactic Harris used. He would let the 190's bounce his flight, and high break at the right moment. After that, the chase was downhill, and not too far, I think they were cruising at like 12000 feet.

Classic "rope a dope".  Both sides used these tactics.  What is most important is spotting the enemy first.

There is no question either that the Spit XIV dominated the FW-190A.

Crumpp

[gripen]

Originally posted by Crumpp
Just stop it Gripen.  Nobody is making anything up.

Anyone can run your numbers throught the formulas here:

http://www.grc.nasa.gov/WWW/K-12/airplane/downwash.html

Please, show us how did you reach 0,1296.

If I put my value, Cl 1,451  for 300 km/h at 3 g, to the formula, I got following result (from 3D to 2D):

Cl = Clo / (1 + Clo /[pi * AR])

=> 1,451= 1,5715/(1+1,5715/[PI *6,02])
=> Clo = 1,5715


Even if I use formula  wrong way (2D to 3D), I got Clo 1,348.
   
gripen

[phookat]

Originally posted by Crumpp
Between the FW-190A8, FW-190A5, and FW-190A3, the A3 will have the worst zoom of all.  It had less weight.

I agree that the A8 zooms better.  But a minor point of clarification.  All else equal, more weight = less zoom.  The reason the A8 zooms better is that it has both more weight and more power, thus drag is a smaller percentage of total force on the aircraft.

[Crumpp]

Gripen,

Please, show us how did you reach 0,1296.

I actually sat down and started workin your numbers Gripen.  Then I realized that you are using different numbers for Cl and factoring in what you say is the "Clo".

Bottom line is what the NASA engineer said about a formula YOU SAID COULD BE NOT BE USED for 2D data but ONLY CALCULATES 3D!!

You THINK you know what the formulas are used for AND everything that has to be factored in but the FACTS are you don't.  Neither do I know everything, I am not an aeronautical engineer.  

Therefore it is totally pointless to argue numbers at our level especially when those number ONLY apply to a specific flight condition with all other parameters being equal.

Leave that to the folks who do know.  HTC will figure out the data they need.

In practical terms it's a stupid debate.  Please either join the discussion or you can go start a new thread and rant about your calculations.

Phookat,

That is the whole point.  The FW-190A gained Horsepower and weight accordingly to increase performance over its lifespan. . By tracking the weight gain and motor derating we can see this.

 Why would anyone produce a version of the same fighter when they have a better performing version already in service, factories already tooled, and workers already producing a better performing product?  It does not make sense.

Sticking to what we can prove.  

1. The popular notion the FW-190 gained tons of weight and lost lots of performance is not true.

Just look at the FW-190A5 level speed chart that has been adjusted for air density differences.

The FW-190A8 level speed chart is not adjusted so we don't know the exact conditions it occurred.  It gives us an idea and falls within the 190A5 density corrections.

http://www.terra.es/personal2/matias.s/fw190.htm

2.  We know for a fact level speed, climb rates, climb speeds, and many of the performance parameters of the Aircraft.  However these facts only come from a few sources.  Since Allied A/C have much data available on each type it is easier to pick and choose the best data.  Example - 4th Fighter group Spitfire site notes the wide variation in performance amoung the fighters of the same type in many of its test.  

Another example is the test pilots at Rechlin testing the FW-190D9 produced different results with each test flight based on Engine condition, prop maintenance, air density, etc. all from the same plane/engine type.  Their results varied as much as 15km/hour at full throttle height.  

3. Performances factors we don't know for a fact can be deducted  by analyzing the tactical trails and thru deductive reasoning produce a fairly accurate approximation of those parameters.

Tactical trials out there are:

P47
F4U
Hellcat
Spitfire Mk V
Spitfire Mk IX Merlin 61

If anyone is missing one of them please let me know.

The Zeke tactical trials give a great reference for how much or little makes a difference in combat.

I have that one too if it is needed.

Crumpp

[Guppy35]

Originally posted by Angus
Guppy:
Do you have more data on these Spit XII missions?

I remember Johnny Johnsson mentioning this tactics. He flew a mission with Harris (the ace). This was the tactic Harris used. He would let the 190's bounce his flight, and high break at the right moment. After that, the chase was downhill, and not too far, I think they were cruising at like 12000 feet.
It was a trap. I think they used Spit XIV's which outperformed the 190's in every aspect except roll at that alt. They just needed them to get down there.
I'll try to dig up more.

Johnnie Johnson's mention of this in his book was a November 17, 1943 flight with the Tangmere Spit XII Wing, led by Wing Commancer Ray Harries.  I have a photo copy of the page from JEJ's logbook that he sent me regarding that flight.  He was flying Ray Harrie's Spit XII that day too.

I have the combat reports for the Spit XII kills from that time as well.

Since the Spit XII was a single stage Griffon, it wasn't meant to perform at high alt, so they needed to entice the 109s and 190s down to them.

They were often used to escort the Medium bombers of the RAF or USAAF and since they usually flew at 18-20K the LW fighters would have the height then too.

On the October 20,1943 mission where they claimed 9 for no loss they were sweeping at 8000 feet when the 190s decided to come down and play.

Dan/Slack

[VO101_Isegrim]

Dunno, but to me such tactics seem to be extremely dangerous, letting enemy fighters to bounce them from above. The 190s get the first shots anyway, and if they have a little bit of tactical sense, they will zoom up after the attack pass was made, ie. their most common RL tactics.

Not that I am saying it wasn`t possible, but to me, it`s sounds like a rather bad idea...

[Crumpp]

What wing was on the Spit XII Guppy?

Looking over the speed data it does not seem all that much faster at lower altitudes than the Spit IX Merlin 66.  The FW-190A8 is a little faster level speed wise.  What struck me though was the best climb speed equals the FW-190's and the angle is steeper.

I think this is the key to the Spit XII's performance vs 190.  It wouldn't mush it's speed as bad when it pulled the nose up and could get up above the 190 without as much horizontal seperation.  This would make it a rougher customer to deal with than a normal Spit Mk IX Merlin 66 (+25).

The Spitfire Mk XII did not gain weight so I don't think it's zoom would be much better than the Mk IX.  It's sustained climb though seems much better suited for combating the 190.  

In the Spitfire Mk IX the best climb speed is well below the FW-190.

On the October 20,1943 mission where they claimed 9 for no loss they were sweeping at 8000 feet when the 190s decided to come down and play.

Grab a copy of:

http://www.airpower.maxwell.af.mil/airchronicles/apj/apj00/fal00/caldwell.html

Here is one from 03 October 1943:

"The Second Gruppe scrambled from Epinoy and was vectored to the east of Beauvais to intercept a formation that proved to contain only Spitfires.  This was No. 127 Wing (RCAF), on a diversion to the Roye airfield.  A large air battle ensued in which Fw. Crump's victory was not confirmed.  S/L Robert "Buck" McNair, whose sixteen victories made him one of the top-scoring RCAF pilots, ditched in the Channel.  He was rescued, but suffered imparied vision that prevented him for returning to combat.  The Spitfire pilots recieved credit for 5 FW-190's shot down.  No Second Gruppe fighter sustained any reportable damage, and there is no evidence for the presence of any other Focke-Wulf combat unit in the area."

Great Stories though!

Crumpp

[Guppy35]

Originally posted by VO101_Isegrim
Dunno, but to me such tactics seem to be extremely dangerous, letting enemy fighters to bounce them from above. The 190s get the first shots anyway, and if they have a little bit of tactical sense, they will zoom up after the attack pass was made, ie. their most common RL tactics.

Not that I am saying it wasn`t possible, but to me, it`s sounds like a rather bad idea...

Think about it for a minute though.  The LW was going to have the advantage regardless as their radar would have allowed them to get up and get the alt advantage.

As the Spit XII leader, at least he was setting it up to have the encounter take place at the alts where his aircraft performed best if, and it was a big if, the 109s and 190s came down.

They often didn't unless the bombers were present.

Of course in 43 you'd have the IXs involved with the high alt specialists VI or VIIs on top cover with the Spit Vs as close cover to the bombers.  A 109 or 190 driver  could potentially encouter 5 different Spit variants on a mission.

Dan/Slack

[Guppy35]

Originally posted by Crumpp
What wing was on the Spit XII Guppy?

Looking over the speed data it does not seem all that much faster at lower altitudes than the Spit IX Merlin 66.  The FW-190A8 is a little faster level speed wise.  What struck me though was the best climb speed equals the FW-190's and the angle is steeper.

I think this is the key to the Spit XII's performance vs 190.  It wouldn't mush it's speed as bad when it pulled the nose up and could get up above the 190 without as much horizontal seperation.  This would make it a rougher customer to deal with than a normal Spit Mk IX Merlin 66 (+25).

The Spitfire Mk XII did not gain weight so I don't think it's zoom would be much better than the Mk IX.  It's sustained climb though seems much better suited for combating the 190.  

In the Spitfire Mk IX the best climb speed is well below the FW-190.



Grab a copy of:

http://www.airpower.maxwell.af.mil/airchronicles/apj/apj00/fal00/caldwell.html

Here is one from 03 October 1943:

"The Second Gruppe scrambled from Epinoy and was vectored to the east of Beauvais to intercept a formation that proved to contain only Spitfires.  This was No. 127 Wing (RCAF), on a diversion to the Roye airfield.  A large air battle ensued in which Fw. Crump's victory was not confirmed.  S/L Robert "Buck" McNair, whose sixteen victories made him one of the top-scoring RCAF pilots, ditched in the Channel.  He was rescued, but suffered imparied vision that prevented him for returning to combat.  The Spitfire pilots recieved credit for 5 FW-190's shot down.  No Second Gruppe fighter sustained any reportable damage, and there is no evidence for the presence of any other Focke-Wulf combat unit in the area."

Great Stories though!

Crumpp

The XII had the clipped Universal Wing with the 2 20mm and 4 303's.  It also had the earlier underwing set up with the smaller Spit V type oil cooler under one wing and the larger box radiator under the other like the V.

You'll also note I wrote 'claimed" on those 9 kills  Everyone over claimed.  Not wanting to start the argument over who did it more btw

Interestingly enough, at least to me, is one of the combat reports on the 10/20 mission that wasn't initially submitted by the pilot for a claim as he hadn't fired at the 109.  The were locked up right on the deck and the 109 stalled out and augered in.

Dan/Slack

[Crumpp]

The XII had the clipped Universal Wing with the 2 20mm and 4 303's. It also had the earlier underwing set up with the smaller Spit V type oil cooler under one wing and the larger box radiator under the other like the V.

That explains it!

Interestingly enough, at least to me, is one of the combat reports on the 10/20 mission that wasn't initially submitted by the pilot for a claim as he hadn't fired at the 109. The were locked up right on the deck and the 109 stalled out and augered in.

Doah!!  Wonder if his last words were " OH SH_TZ!"

BTW that is a smart tactic to stay at the best altitude for you fighter.  Peter Crump relates a story in JG War Diaries about being caught at "bad altitude" for your kite.

He says their FW-190s hung like "fat bloated sausages" in the air while he watched P47's dive in on them.  He used the stall of the 190 to snap into a spin and recovered it below the clouds.

Crumpp

[Nashwan]

You'll also note I wrote 'claimed" on those 9 kills

I've got a description in my notes (no idea where it's from now) of the encounter on 20th Oct 43, it says German losses were 9, as per the claims (I've got 9-0-1 for the claims). Losses were 109G6s and 190s from JG2, inc Friedrich May, (29 kills).

It claims the kills "included kills by"Harries, Doll, Kynaston, Bulmer and Nash

I don't know how accurate it is though, because I didn't note the source.

[gripen]

Originally posted by Crumpp
I actually sat down and started workin your numbers Gripen.  Then I realized that you are using different numbers for Cl and factoring in what you say is the "Clo".

Before your Cl calculation on my numbers, I had claimed just one Cl value (Cl 1,451) for the Fw 190 at 300 km/h so there should be no confusion. Why don't you just tell how did you reach that Cl 0,1296? Should be easy.

Originally posted by Crumpp
Bottom line is what the NASA engineer said about a formula YOU SAID COULD BE NOT BE USED for 2D data but ONLY CALCULATES 3D!!

In practice there is no way to determine 2D lift coefficient data of a certain profile accurately from the flight test data, therefore the Clo of the wing profiles are determined in the wind tunnel. Of course we can calculate Clo for a plane with varying wing profile like the Fw 190 but it's pretty much meaning less number. Your source says:

"So an engineer has to be very careful when using lift coefficients. You have to find out how the particular value was generated (2D or 3D model) .. and there some other aerodynamics effects (like boundary layers and shock waves) which can effect the value as well. You can only apply the lift coefficient to a real case which is similar to how the original model was tested."

What I'm asking here is you to tell how "the particular value was generated".

gripen

[MiloMorai]

JG26 lost 31 a/c due to enemy action in Oct 43.

I - 10 > 190A-4 (3 out of 6), -5 (2 out of 6), -6 (5 out of 33)
II - 16 > 190A-4 (0 out of 2), -5 (2 out of 7), -6 (14 out of 36)
III - 5 > 109 G-3 (1 out of 6), -4 (10 out of 6), -6 (3 out of 36)

according to http://www.ww2.dk/

II./JG26 had a hard time vs the RAF/USAAF in Oct. 43 suffering 35.6% action casulties (A-6 (the latest and greatest), 38.9% of strength) compared to I. with 22.2% and III. with 10%.

[Crumpp]

Your Right Nashwan!

20 Oct '43

It was big rodeo that day with several bomber formations and lots of fighters in the air.

The 8th AF conducted the Duren raid.

II/JG26 mission was a fiasco.  There was a thick layer of rain clouds covering France that day.  II Gruppe got broken up climbing through the clouds and broke out of them as scattered individuals right underneath an escorting squadron of P47's.

The scattered pilots attempted to fight off the P47's and intercept the bombers.  

The FW-190A6's paid the price with 3 casualties from the P47's and 1 from the B17's.

III/JG26 flying a mix of Bf-109G3's, G4's, and G6's lost 2 pilots to B17's and 2 to P47's.

The Mk XII's are mentioned in the Diaries though:

------------------------------------------------------------------------------------

The day as a whole was a minor disaster for the German Defenses.  Only nine B-17's were shot down, for the loss of nineteen German pilots killed or injured.  The losses of JG2 were about equal to JG26's.  The Richthofen fighters approach was broken up completely by the Spitfire Mk XII's of the Hawkinge Wing, which shot down 10 Messerschmitt's and FW-190's without loss.
JG 26 lost six pilots killed, and two injured. And nine of it's aircraft wrecked.  All of the casualties of the Schlatager Geschwader were 1943 replacements, boding ill for the future; it is certain none of the five pilots shot down by P47's had the skill or experience Peter Crump needed to survive after being bounced at 34,000 feet.

------------------------------------------------------------------------------------

JG26 claimed 5 Spitfires (not Mk XII), 2 P47's, and 4 B17's.

Looks to me like the Spitfire Mk XII's were at worst co-alt and probably above as the main Luftwaffe Objective was the bombers.

Crumpp