Author Topic: Maybe the 190s arent wrong....or how to be really unpopular in 1 step  (Read 12873 times)

Offline Simaril

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I've really enjoyed some serious file hunting lately, and I came across these 2 reports that might have some bearing on recent and continuing LW whines....I mean AH constructive criticism.

So here goes....





And the second report, using different airframes at the UK's testing center:






Now, these tests werent looking at exactly the same thing, but they are similar in pointing out that the Fw190 didnt do nearly as well down low -- and at slow speeds. As others have suggested, this situational factor may explain the major difference seen between the reported WW2 experience with Fw190s and the "AH2 experience." Most combat here is -- or quickly ends up -- low and slow, where the 190 wasnt designed to be and where it apparently became so unstable that it took lots of work to keep "in the game".

The 1944 report goes into more detail about handling charactereistics, but it also seems to be the less standardized of the 2 (as we'd expect in field testing rather than testing centers). The 190 engine is described as being very rough: while I dont pretend to know if that was usually the case for the bird, it may represent poor tuning by the US mechanics. On the other hand, if the engine required the hands of an artist to run right, it may have run rough indeed late in the war.

These reports (particularly the first one) suggest that the LW may not be discriminated against at all. I've elsewhere expressed my opinion that the "conventional wisdom" about HT preferring US rides for marketing reasons is nonsense (brief synopsis: other games with dominant non US equipment flourish), and these papers raise the possibility that HTC is spot on.
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Offline 1K3

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Maybe the 190s arent wrong....or how to be really unpopular in 1 step
« Reply #1 on: January 27, 2006, 04:28:49 PM »
how about the ailerons?

It is said that if Fw-190s ailerons are not properly adjusted the port or starboard wing will dip, causing hi speed stall that is currently WAY higher than any plane in this game.

Offline Simaril

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« Reply #2 on: January 27, 2006, 04:38:10 PM »
Quote
Originally posted by 1K3
how about the ailerons?

It is said that if Fw-190s ailerons are not properly adjusted the port or starboard wing will dip, causing hi speed stall that is currently WAY higher than any plane in this game.


Look at the second page with the red underlining. The stall instability was described as "extremely bad" in turns, and then separately the report says that even at high speed you can get "straight down spins" if "trimmed and pulled hard enough".

I'd take that to mean that trimmed right the stalls were a big problem, but even at the planes optimal speed you could still get the spins if you were heavy handed trimming or controlling.
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Offline Sable

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Maybe the 190s arent wrong....or how to be really unpopular in 1 step
« Reply #3 on: January 27, 2006, 05:20:07 PM »
Frank Klibbe of the 56th FG described a dogfight in early 44 where we found himself in a tight lufberry circle in his P-47 at 8000ft with a 190 on his tail.  The way he describes the fight, it sounds like the 190 is using a series of high yoyos to get in firing position.  After a few minutes of failing to hit him, Frank had gained a little and the 190 rolled out and left.

In the Jugs vs. 190s snapshot this week, I found myself doing this same thing in a 190.  I'd get on the 6 of a Jug, and if I didn't get it right away, it would start to outturn me a bit.  I'd then use a high yo-yo to come diving back down on them to get another shot.  

This makes sense to me, as the 190's wing loading is actually a bit worse the the P-47, but it's rate of climb is somewhat higher (meaning it has more excess power to use for manuevering).  

In the game it seems to work out that the combo of pilot skill and energy situation is the deciding factor.  And that seems to fit pretty well against the stories I've read - sometimes the 190s won, sometimes the 47s won.

Offline Angus

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Maybe the 190s arent wrong....or how to be really unpopular in 1 step
« Reply #4 on: January 27, 2006, 06:33:19 PM »
Thumbs up for HiTech.
Or HTC rather :aok :aok
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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Maybe the 190s arent wrong....or how to be really unpopular in 1 step
« Reply #5 on: January 27, 2006, 07:40:11 PM »
Problem is that the BMW801 did not run rough in Luftwaffe service.  The FW-190A5 did have an altitude band were heavy vibration was experienced but this was solved.  It was a consequence of overcooling the frontbank of cylinders.  The band was narrow and at high altitude.

Aileron adjustment, not trim, is very important to the FW-190's turn ability.  A Luftwaffe technical bulletin specifies the stall characterisitics of the Focke Wulf with properly adjusted ailerons.

Only the Focke Wulfs horizontal stabilizer was adjustable in flight for trim.  All other surfaces had fixed trim tabs.

It specifically states that the stick will burble just before the stall.  This is also confirmed by the Luftwaffe veterans who flew the Focke Wulf.  Properly adjusted the aircraft gave warning.

The stall speed will change according to CG adjustment as well.  Testing reports I have put the power on stall speed clean between 90-110mph depending on configuration.

I don't think this report of an P47D4 with water injection and High activity propeller vs an FW-190G series has the Focke Wulf Yo-Yoing.  It is level turning below 250IAS.

Quote
meaning it has more excess power to use for manuevering


Wingloading has little effect on turn radius.  Power loading is the key to angle of bank.  A small reduction in radius adds up to a large improvement in turn rate.

 

Thrust also contributes a portion to lift and reduces stall speed:
 

So the "rough running engine" or loss of power experienced by the allies use of natural petroleum fuels in the BMW801 is very significant to the performance of the aircraft.

All the best,

Crumpp

Offline Simaril

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Maybe the 190s arent wrong....or how to be really unpopular in 1 step
« Reply #6 on: January 27, 2006, 09:46:51 PM »
Crumpp,

I was hoping you'd reply, as your LW knowledge is far deeper than mine.

As to the rough runnning engine, I came across several references in British reports as well as the USAAF one I posted, that refer to the rough running 190 engine. The report I read followed up by interviewing captured pilots who apparently stated that the 190 engine ran rough normally and was a cause fro their concern. They apparently also told the Brits that they were very uncomforatble over water because of the engine's percieverd reliability.

These reports do not identify the version of the 190. The one I'm remembering did say that the test sample was "apparently downrated" because the settings at time of capture didnt match the placards.

Lastly, I'm not sure how decreased power woudl affect stall characteristics; wouldnt it more affect the stall threshold than the suddenness or controllability of the stall?

I can post these if desired. What are your thoughts?

Simaril
« Last Edit: January 27, 2006, 09:49:17 PM by Simaril »
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Offline Crumpp

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Maybe the 190s arent wrong....or how to be really unpopular in 1 step
« Reply #7 on: January 27, 2006, 10:47:34 PM »
Hey Simari,

Glad to be of help.


Quote
The report I read followed up by interviewing captured pilots who apparently stated that the 190 engine ran rough normally and was a cause fro their concern.


Of course they told the British the problems the RAE experienced were normal.  You would not expect them to be disloyal to their country and jump in to help solve the issues would you?

I can just picture some German POW thinking:







"Why yes Mr interrogator, we hated the damn thing too.  Always ran rough like that.  In fact I was scared to death it was going to fall out of the sky on the flight over!"

The Luftwaffe personnel were trained to maintain the design not the allied personnel.  A properly maintained BMW801 does not vibrate anymore than any other radial engine.

The synthetic fuel the Germans used requires a different engine set up.  Hotter plugs, timing, and mixture changes etc...  The allies simply did not have sufficient quantities of it to allow for flight testing of captured aircraft.    

Quote
Lastly, I'm not sure how decreased power woudl affect stall characteristics; wouldnt it more affect the stall threshold than the suddenness or controllability of the stall?


No one has claimed differently.

What I said was:

Quote
Thrust also contributes a portion to lift and reduces stall speed:


Aileron adjustment does affect stall characteristics and causes the stall to occur early.  It also causes the stall to be much more violent.

Notice that nowhere in the extensive trials of WNr 313 is the harsh stall mentioned.  A high stall speed is noted of 110 mph and is most likely due to the poor performance of the motor the RAE experienced.

While I cannot say for a fact this particular aircraft had ailerons in need of adjustment, the harsh high speed stall is an indicator.  

I am sure if WNr 313 exhibited these same stall characteristics the RAE would have duly noted them.

All the best,

Crumpp

Offline Karnak

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Maybe the 190s arent wrong....or how to be really unpopular in 1 step
« Reply #8 on: January 28, 2006, 03:14:16 AM »
Well, it was a capture Japanese technician that apparently fixed the capured A6M2 so it didn't suffer negative G engine cutouts, so you never know. :p
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Offline justin_g

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Maybe the 190s arent wrong....or how to be really unpopular in 1 step
« Reply #9 on: January 28, 2006, 03:38:34 AM »
Quote
Wingloading has little effect on turn radius.

1. So a modern jet fighter could use its massive excess thrust to turn a smaller radius than a 50hp Piper Cub? No, I don't think so.

Wingloading(or more accurately, liftloading) is the primary factor in determining turn radius.

Quote
Power loading is the key to angle of bank.

True(For sustained, level turns).

BUT: From the graph you can see that an increase in bank angle also requires a higher speed. Bank angle has a fixed relationship with G-load, thus the G-load is also increased.

Since A=V^2/R you can see that an increase in bank angle will:

1. increase G-load(A), which requires:
 a. an increase in speed(V).
 b. and/or a decrease in radius(R).

Doing the math for various angles of bank(using data from graph):

30º bank = 1.15G @ 102mph. R = 183m (Turn time = 25s)
45º bank = 1.40G @ 113mph. R = 184m (Turn time = 23s)
60º bank = 2.00G @ 131mph. R = 175m (Turn time = 19s)
70º bank = 2.9G @ ~158mph. R = 174m (Turn time = 15.5s)
80º bank = 5.8G @ ~224mph. R = 177m (Turn time = 11s)

You can see that as bank angle is increased, the turn radius is not reduced by much, but speed and turn rate are increased by a large margin.

Quote
A small reduction in radius adds up to a large improvement in turn rate.

This can be seen easily on an EM diagram, or the examples above. The small reduction in radius is tied to a large increase in speed and G-load, to thus increase the turn rate.

Quote
Thrust also contributes a portion to lift and reduces stall speed

The added thrust will cause the aircraft to climb. WW2 fighters had enough excess thrust to climb even at stall speed, there is no way you can use this excess thrust to reduce speed, unless you can increase the AoA. But you cannot, because you are already at Clmax.

Prop planes have lower stalling speeds with some added thrust because the prop wash increases the local velocity of the air over part of the wing, increasing the lift generated by that part of the wing. It has rapidly diminishing returns though, as can be seen in the NACA trials with Spitfire V stalling speeds. Increasing power from 3.75lbs to 7lbs boost only lowered stall speed by 1mph.

Offline HoHun

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Re: Maybe the 190s arent wrong....or how to be really unpopular in 1 step
« Reply #10 on: January 28, 2006, 08:02:03 AM »
Hi Simaril,

>These reports (particularly the first one) suggest that the LW may not be discriminated against at all. I've elsewhere expressed my opinion that the "conventional wisdom" about HT preferring US rides for marketing reasons is nonsense (brief synopsis: other games with dominant non US equipment flourish), and these papers raise the possibility that HTC is spot on.

Thanks for the reports! :-)

When they first surfaced, I prepared a performance analysis based on absolute data for a captured Fw 190 tested in the US, and absolute data for a P-47D from a US report, and concluded that the tested Fw 190 was a bit lacking in performance as the report shows it falling behind in climb, indicating a lack of power in spite of reaching the proper boost pressure.

Of course, this lack of power would make the Fw 190 lose a bit of its edge in most points of the comparison.

Here is the original thread, but unfortunately, I only linked my analysis instead of re-posting it, and it seems it was lost when the AAW board where I actually posted it went down:

http://www.hitechcreations.com/forums/showthread.php?s=&threadid=74720&highlight=italy+captured

So though the details are lost and I'm working from memory, I'd suggest not to focus on stall too much as there was definitely a power issue.

Regards,

Henning (HoHun)

Offline Simaril

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Maybe the 190s arent wrong....or how to be really unpopular in 1 step
« Reply #11 on: January 28, 2006, 10:30:35 AM »
HoHun:

Did you base yuor analysis of these reports, or on others like them?
 


AS I've thought about it, the British Air Fighting Development Unit report (which compared to a P-47C) didnt report the impressive stall characteristics that the more informal US field testing one did a year or so later. (The 1944 report was based on flight tests in Italy in 1943). With Crumpps suggetions, I'm wondering if its airelon trim was off, while the British example was trimmed at time of capture. Alternatively, the US pilot may jsut have not been as experienced.

It seems to me, though, that if the trim had to be set before takeoff, wouldnt that have already been done on a captured bird that had already been flown by the germans?

What caught my non-engineer's eye in these reports was the qualitative sense of stall difference highlighted in the US paper, since their description pretty well matches the AH experience of having to fight stall harder and earlier in the 190s compared with the US rides.

Quote
originally posted by HoHun

Notice that nowhere in the extensive trials of WNr 313 is the harsh stall mentioned. A high stall speed is noted of 110 mph and is most likely due to the poor performance of the motor the RAE experienced.

While I cannot say for a fact this particular aircraft had ailerons in need of adjustment, the harsh high speed stall is an indicator.

I am sure if WNr 313 exhibited these same stall characteristics the RAE would have duly noted them.


HoHun, I'm not familiar with the abbreviations...WNr 313, RAE?
« Last Edit: January 28, 2006, 10:40:40 AM by Simaril »
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Offline MiloMorai

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Maybe the 190s arent wrong....or how to be really unpopular in 1 step
« Reply #12 on: January 28, 2006, 11:12:10 AM »
WNr 313 is the German serial number of the 190.

RAE = Royal Aircraft Establishement.

Offline Crumpp

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« Reply #13 on: January 28, 2006, 01:32:59 PM »
Quote
Well, it was a capture Japanese technician that apparently fixed the capured A6M2 so it didn't suffer negative G engine cutouts, so you never know.


Hi,Karnak,

No you don't but I am sure it would have been noted had a prisoner been cooperative.  Instead the reports simply notes it is understood from POW's has confirmed the engine runs rough.

Implying they were cooperating, while possible, is not the most likely explanation IMHO.

Additionally we do not know the experience of the POW.  He could be very well speaking the truth from his point of view but referring to the time before his capture and experience in the BMW801C powered versions.

Facts are the BMW801D2 did not run rough in Luftwaffe service when properly set up or maintained.

Quote
What caught my non-engineer's eye in these reports was the qualitative sense of stall difference highlighted in the US paper, since their description pretty well matches the AH experience of having to fight stall harder and earlier in the 190s compared with the US rides.


That is because the FW-190's flying characteristics in AH are modeled from Allied reports.

Quote
WNr 313, RAE?


WerkNummer 313 = Serial Number of Oberstleutnant Arnim Faber, Gruppen-Adjutant III/JG2 FW-190A3.

RAE = Royal Aircraft Establishment = Organization responsible for the testing captured enemy aircraft.

Quote
With Crumpps suggetions, I'm wondering if its airelon trim was off, while the British example was trimmed at time of capture.


That is pretty much what I think.  I have found no evidence or mention of the harsh stalling in the RAE reports on WNr. 313.

Aileron adjustment was off in some of the US aircraft.  On several captured FW-190's flown I can prove the ailerons were out of adjustment.

The Luftwaffe had a difficult time keeping the ailerons adjusted.  IMHO the design of the adjusting blocks was not one of Focke Wulf’s highpoints.  Why they did not add teeth to the mated surfaces is unknown.  Instead they left them smooth with the tension of two bolts to hold them at the adjusted point.  The adjusting block bolt rides in a long oval groove with only the flanges of the bolt making contact with the block.

I am sure that just taxing around a bumpy field would cause the ailerons to come out a adjustment in a short period of time.  This aspect of FW-190 maintenance and it's importance to the flight characteristics of the aircraft is very much emphasized in the maintenance instructions.

For the low speed stall:

The "no warning stall" in the FW-190 is not correct.  The ailerons would vibrate just before the stall when properly adjusted.  They would not reverse, however.  Oscar Boesch has told me that you had to pay attention, however.  If your mind was on anything other than flying the plane or you were not relaxed you could miss it.  Once you got used to it though, it became second nature to him.  So it was not a huge amount of warning.  When you felt the bumping and your stick forces disappeared, relax the backpressure immediately.

Properly adjusted recovery was immediate with a relaxing of the stick.  Left unchecked the wing would dip and develop into a spin.  Which is pretty much most single engine fighters.

For the high speed stall:

It is a fact that the FW-190 can enter an aggravated stall at high speed.  All aircraft with the ability to change AoA fast enough and at high enough speeds can do this.  Many WWII fighters have too high a Stick Force Per G to do this or lack the elevator authority under G to change the AoA fast enough to create the stall conditions.

Oscar also has related you pretty much had to be crass to do this unintentionally.  As the US pilot relates, it required trimming the nose down and a rather violent yank of the stick.  Aero elasticity would remove the twist in the wing.  The twist was put there to reduce the harsh stall of the NACA 230XX airfoils.  This would shift the load outboard of the wing and bring the CL to nearly equal alone the span.  If the wing was then stalled in this configuration it would stall alone most of the span at the same time causing the wing to rapidly drop.  Left unchecked the aircraft would invert and spin.  This characteristic was actually used by many Focke Wulf pilots as an escape manuver.

Quote
Wingloading(or more accurately, liftloading) is the primary factor in determining turn radius.


Good post Justin.  

 


It takes a significant increase in liftloading.  A moderate increase can easily be overcome with powerloading and thrust.

With increased thrust, the Spitfire Mk XIV was able to overcome a 1000lb weight increase and a 5lb sq ft wingloading increase. It simply was able to pull a larger angle of bank at the same speed than the Spitfire Mk IX. This reduced the turn radius, increased the turn rate, and allowed it to match the much lower wingloading of the Spitfire Mk IX.

Quote
The tactical differences are caused chiefly by the fact that the Spitfire XIV has an engine of greater capacity and is the heavier aircraft (weighing 8,400 lbs. against 7,480 lbs. of Spitfire IX).


Quote
The all-round performance of the Spitfire XIV is better than the Spitfire IX at all heights. In level flight it is 25-35 m.p.h. faster and has a correspondingly greater rate of climb. Its manoeuvrability is as good as a Spitfire IX. It is easy to fly but should be handled with care when taxying and taking off.


Quote
The turning circles of both aircraft are identical.


http://www.spitfireperformance.com/spit14afdu.html


All the best,

Crumpp
« Last Edit: January 28, 2006, 01:36:43 PM by Crumpp »

Offline Angus

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« Reply #14 on: January 28, 2006, 06:03:05 PM »
Ehh,,,,,look a wee better into this:
"Wingloading has little effect on turn radius"

Same wing with more loading and same power: YES. It does have a negative effect on turn radius.

A superior wing will give better liftloading.

Then you have powerloading.

But with the same wing, just more loading, WINGLOADING HAS EVERYTHING TO DO WITH ITS EFFECT ON TURN RADIUS!

The difference in liftloading pr sqr in WW2 fighters is not so much, so while  liftloading will give a better comparison, it's not all.

And if you have different wings to compare, - well, you have Wingloading, liftloading, spanloading, bank angle, and even chord to play with, as well as G's & wing shape/characteristics, plus induced drag, - and at what speed?
Turning aint just turning.....

Before you go further, powerloading, elevator authority, C.o.G. and departure characteristics..........
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)