Author Topic: It's official...  (Read 8051 times)

Offline Crumpp

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« Reply #240 on: December 20, 2005, 10:11:56 AM »
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And Crumpp, - you couldn't rip the wing of a Spitfire with an aeleron turn,- you're stuck with "would" again.


Not my words Angus, a Spitfire test pilots who flew a captured FW-190.

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The quick pitch of the Spitfire as you hopefully remember could also not easily be followed,- no wonder, - it had to be calibrated down so it would not break the aircraft.


Obviously you have not seen the elevator forces over G measurements of the Focke Wulf FW-190.  The elevator was extremely effective.  Over-effective in fact.  With the rearward CG of the FW-190A3/A4 it was even easier to overcontrol the aircraft.  Overcontrolling will make it appear that the elevator is not effective.

We have covered this before.

At 2 KM altitude, it takes 1 degree of elevator movement on the FW-190 to load 1100kg/m2 on the aft at 450 kph.

At 2 KM altitude at 300kph 1 degree of elevator movement delivers 490Kg/m2.  Hardly ineffective and certainly the results the RAE obtained were due to inexperienced pilots overcontrolling the aircraft.

To put that into perspective, the FW-190 has a stick gearing of 4.1 degrees per inch and 31 degrees of upward elevator movement.

As Oscar and the other FW-190 pilots have related, the Focke Wulf was a true one handed aircraft for most of the envelope.  Flying it with two hands, as you would a Spitfire, 109, or Hurricane is a recipe for overcontrolling it.

All the best,

Crumpp
« Last Edit: December 20, 2005, 10:15:53 AM by Crumpp »

Offline Kurfürst

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« Reply #241 on: December 20, 2005, 10:23:07 AM »
Neil Stirling has just posted some nice numbers on butch boards :

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As of 18th May 1944.

Spitfires with Sqn's

MkV 531
MKVII 62
MK VIII 209
MK IX 996
Mk XII 22
MK XIV 61.

Neil.
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Offline Angus

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« Reply #242 on: December 20, 2005, 10:37:28 AM »
Funny how many of those sorry V's were still flying then :D
Anyway, Kev, I'd put the XVI with the IX basically - it's very much the same.

And Crumpp:
"Overcontrolling will make it appear that the elevator is not effective.

We have covered this before."

Obviously you have not comprehended this before. The problem on the Spitfires end was that the elevator kept BEING effective. Feel and action alike. Coupled together with the delicate C.o.G. this could break the aircraft with forces presumably in excess of 12G.
When entering the problem, if the pilot was quick enough, he would bunt and get out with a blue eye. The elevator was still effective.
So, they weighted it up a bit.

Got a test pilots description on it that I bet none of you have, (A.Bartley)  as well as Quill's describtion :D
It was very interesting to carry out the flight trials at Rechlin with the Spitfire and the Hurricane. Both types are very simple to fly compared to our aircraft, and childishly easy to take-off and land. (Werner Mölders)

Offline Guppy35

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« Reply #243 on: December 20, 2005, 10:55:56 AM »
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Originally posted by Kurfürst
A large number of MkIX were just converted MkV airframes. And, looking on the numbers it seems the production of the MkIX did not run up until 1944.

In 1942 only the Merlin 61 one was producted, Hop/Nashwan claims that w/o a source as only 350, inc. some 1943 production.

Say, 300 MkIXs produced in 1942.

And looking how slowly the new Squadrons emerged, well...

June 1943 - 19 Squadrons
Sept 1943 - 29 Squadrons
Dec  1943 - 39 Squadrons of MkIX.

It took them a steady 3 months to equip 10 new squadrons, with 12+8=20 planes each. That's 300 planes if we assume reserves and losses, or 100 MkIX produced a month and I am being very generous here.


That's a very small scale, but given what we were shown about the MkXIV production, and the fact that the mkV was still produced in 1943, I am not surprised. Perhaps there was shortage of proper engines. Most seem to have been produced in 1944, which is when coincidently the IX finally replaced the V with most units.


Not sure what you mean about a large number of IXs being converted Spitfire Vs.

THe IX was built using the Spitfire Vc airframe.  It was a Spitfire Vc with a two stage Merlin 60 series engine.

The Spitfire XII had the first 50 built on the Spitfire Vc airframe.

The Spitfire XVI was the same as the IX which means it was built off the Vc.

The VII, VIII, XIV etc were built of the strengthened airframe that was the basis for the VIII.
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Offline Guppy35

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« Reply #244 on: December 20, 2005, 11:11:35 AM »
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Originally posted by Kurfürst
I didn't say there were only 10 Squads of IX til mid-1944.  I said there were 35-odd MkV and 10 MkIX squadrons, I should have added its for the Figher command (see John Foreman) in June 1943, but the ratio beween MkV and IX was correct even then.

Though this small diffo between 56 Sqns operating the type at one time  or another, and the absolute max. of 39 Squadron operating the type at one time by the end of 1943 didn't bothered you until I pointed out the correct facts..

Moral of story, the IX was not the mainstay Spitfire until 1944, period. MkVs must have had a bad time vs. 109Gs.


LOL you correcting the facts.  I love that.  Based on your facts, the LW won the war and the 109 was the best piston engined fighter ever built.  Maybe you should argue with Crumpp for a while about how much better the 109 was then the 190.  Maybe he'd have the patience for it :)

Lets narrow it down for you.  The frontline squadrons of 11 Group that carried the fight to France, were primarily equipped with the Spitfire IX.  Throw in the two XII squadrons and the Tiffies and that about covers 11 Group.  Were there Spit Vs operating over France in 43? absolutely.  And they were generally the clipped Spitfire LFVs flying the close escort to the medium bombers of 2 Group or the USAAF.  But of course they had high cover from the VIIs and IXs as well as cover from the XIIs and Tiffies.

How many LW fighters based in France to oppose those RAF fighters along with the USAAF fighters?  How many 109s in France compared to IXs operating in England?

OF course as always, this is a waste of time as you aren't listening anyway
Dan/CorkyJr
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Offline Crumpp

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« Reply #245 on: December 20, 2005, 11:16:02 AM »
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The quick pitch of the Spitfire as you hopefully remember could also not easily be followed,- no wonder, - it had to be calibrated down so it would not break the aircraft.


Man, Angus, do you understand the report where the elevator of the Mk V was bob weighted?

All aircraft have the ability to overload the airframe in an overspeed condition.  Aircraft designers purposely build in higher forces in the elevator to keep the pilot from killing himself and destroying the airplane.

Having light elevator forces at high speed is a design flaw, not a feature.  Installation of bob weights is one method designers can use to cover up this flaw.

http://img106.potato.com/img.php?loc=loc24&image=7169f_elevator_limits.jpg

http://img128.potato.com/img.php?loc=loc24&image=23498_spits1.jpg

The Spitfire was fitted with bob weights, however the consequences of this design flaw would continue to haunt the design.

http://img15.potato.com/img.php?loc=loc24&image=6c879_bobweightopinion.jpg


All the best,

Crumpp

Offline Crumpp

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« Reply #246 on: December 20, 2005, 11:28:07 AM »
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Obviously you have not comprehended this before. The problem on the Spitfires end was that the elevator kept BEING effective. Feel and action alike. Coupled together with the delicate C.o.G. this could break the aircraft with forces presumably in excess of 12G.


You need to read the report Angus.  Push force was required to keep the accellerations under control.  Why do you think the pilot would have to alternate push then pull forces?

Phugoid oscillations or the beginings of Spiral dive.  Both symptoms of a stability problem caused by elevator design in the Spitfire.  You keep wanting to claim "elevator effectiveness".  Unfortunately the problem has nothing to do with effectiveness of the elevator.

"Elevator effectiveness" is not even mentioned in the report!  What is discussed is the design flaws of the elevator balancing and fabric distorsions which cause the stability issues.

All aircraft if designed badly, can destroy themselves in an overspeed condition.

All the best,

Crumpp
« Last Edit: December 20, 2005, 11:38:00 AM by Crumpp »

Offline MiloMorai

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« Reply #247 on: December 20, 2005, 11:30:05 AM »
From the 5th order for Spitfires, production from Feb to Nov '42

MK IXs - 188

From the 6th order for Spitfires, production Dec '42 to Apr '43

Mk IXs - 39

From the 7th order for Spitfires, production from Nov '42 to Aug '43

Mk IXs - 160

From the 8th order for Spitfires, production Mar to June '43

Mk IXs - 417

If you were not so cheap Kurfy and bought Spitfire: The History you would have these numbers.

To help with your ignorance of the RAF:

RAF squadrons from 1 to 299 were British squadrons

The 300 series of squadrons were for for other nationalities flying with the RAF

The 400 series of squadrons were for Commonwealth squadrons

The 600 series were originally for 'Auxillary AF' units (week-end warriors)

The 700 (training and ancillary) and 800 (operational) series of squadrons were for the FAA. (860-879 Commonwealth and allied navy squadrons)
« Last Edit: December 20, 2005, 11:35:05 AM by MiloMorai »

Offline Angus

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« Reply #248 on: December 20, 2005, 11:36:26 AM »
Crumpp:
Pull=up and into a turn if the position is such
Push= down

Weighting them a wee with BoB weights completely cured the problem.

The problem being that at a high speed enough the pilot could pull the aircraft into a narrowing circle, as well narrowing itself with the shift of C.o.G. aftwards. The control still remained effective, hence the chance of getting out, which some of the quickest sticks did.
Bottom line hypersensitive and very hypercontrollable elevator that needed to be weighted down to make it easier to handle. Happened, was done, - won't get much better.
It was very interesting to carry out the flight trials at Rechlin with the Spitfire and the Hurricane. Both types are very simple to fly compared to our aircraft, and childishly easy to take-off and land. (Werner Mölders)

Offline Crumpp

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« Reply #249 on: December 20, 2005, 11:38:55 AM »
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The problem being that at a high speed enough the pilot could pull the aircraft into a narrowing circle, as well narrowing itself with the shift of C.o.G. aftwards. The control still remained effective, hence the chance of getting out, which some of the quickest sticks did.


Do you even have the report?  What shift in CG????  The CG does not change during the dive.

WTF are you talking about?

The pilot did not pull anything Angus.  The aircraft was unstable and he was pushing and pulling the stick to keep it from destroying itself.

Bob weights provide a constant pull to improve stability issues!
 

Rate of change of angle, your thinking of as "elevator effectiveness" has nothing to do with stick force gradiants.  It is a design function of the area of the tail to elevator control surface.
 

Now there are many other factors which effect the angle rate of change, stability is one of them.  Stability problems do not improve the controllability of the aircraft or it's combat useful characteristics.

Funny how fandom can turn a liability into an asset.  

The stick force gradiants being too low is a flaw both the FW-190 and the Spitfire shared.  The FW-190 did not have the stability problems though.

All the best,

Crumpp
« Last Edit: December 20, 2005, 12:49:16 PM by Crumpp »

Offline DoKGonZo

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« Reply #250 on: December 20, 2005, 12:48:14 PM »
... I really gotta try to install a Wiki on my server over the holidays so we can start capturing all this data in one place ...

Offline gripen

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« Reply #251 on: December 21, 2005, 05:53:43 AM »
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Originally posted by Kurfürst

Nope, you are completely wrong. The Merlin 66 and 266 had exactly the same rating.

 


If we look the speed values in the same sheet, we got different a bit different picture:



The sheet gives same rating as for the Merlin 66 but 1500ft higher 2nd FTH and 2mph higher top speed if compared to the LF. IX values.

gripen

Offline Kurfürst

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« Reply #252 on: December 21, 2005, 06:02:15 AM »
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Originally posted by Guppy35
Lets narrow it down for you.  The frontline squadrons of 11 Group that carried the fight to France, were primarily equipped with the Spitfire IX.  Throw in the two XII squadrons and the Tiffies and that about covers 11 Group.


At what period ? By 1944, certainly. In 1943, and even more so in 1942, certainly not. Ramrod S.36 , flown 6. september 1943 , out of 32 spitfire squads, 18 still flew Mk.V



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How many LW fighters based in France to oppose those RAF fighters along with the USAAF fighters?[/B]
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Certainly a lot less, there was no reason or threat coming from the RAF to make the Luftwaffe think about more fighter should be deployed in France. But, they were provided with the technological edge, receiving always the latest models, whereas the RAF was pretty slow in getting the 'anti-190' MkIX in service in numbers.


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How many 109s in France compared to IXs operating in England?[/B]


A handful, since most of the Gruppes at the Channel had FW 190, the 109s were mostly of pressurized high altitude types with GM-1, providing high cover and other special tasks.

But why narrow it down to France? There was nothing important happenning there, the RAF launched nuisancse raids for years with a handful of bombers as bait, but the LW didn't buy the trick as the JG2/26 kill ratios show. The Bf 109s were primarly used in the Med, and that's where Spitfires and 109s mostly met.  And there the ratio of MkVs was even higher vs. MkIX. The typical Spitfire vs. 109 engagement in 1943 was usually 109G-2, G-4 or G-6 facing old MkVs against which they were quite superior, or when a MkIX turned up once in a month, it put them on equal footing.


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OF course as always, this is a waste of time as you aren't listening anyway [/B]


Well perhaps back up your statements with OOBs of 11 group in 1943, or the sortie statistics of MkV vs MkIX in 1943, and then your posts will have more weight than what they seem now, an mere opinion.
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Offline Crumpp

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« Reply #253 on: December 21, 2005, 06:14:47 AM »
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If we look the speed values in the same sheet,


:rofl

Offline Kurfürst

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« Reply #254 on: December 21, 2005, 06:35:18 AM »
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Originally posted by gripen
If we look the speed values in the same sheet, we got different a bit different picture:



The sheet gives same rating as for the Merlin 66 but 1500ft higher 2nd FTH and 2mph higher top speed if compared to the LF. IX values.

gripen


I thought we were discussing engine outputs and rated altitude, not top speeds, you should understand the difference.

As I understand, your point to ignore/dismiss the engine ratings given for the Merlin 266 by the datasheet, and then speculate about the top speeds based on the same datasheet you dismissed two times already...?

Besides, there was hardly any difference between the Mk IX/Merlin 66 top speeds between 19500 and 24 000 feet, just let's look at the BS 310 curve (or the others), which gives the 404mph top speed, the same as qouted in the IXLF datasheet.

Trouble is, there's practically no change in speed between 19500 and 24 000 feet... pretty much 403-404mph all the way :

http://www.spitfireperformance.com/ma648speed.gif

Appearnaltly the IXLF and the XVI has the very same performance. Simply because they have the same engine. I can easily see that 2 mph diffo coming from some airframe factor between the IX and XVI, most likely from the reduced drag from clipped wings.
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