Bf-109 vs P-40

[HoHun]

Hi Flyboyj,

>Well Henning, maybe he should, but does that make any of his less significant when he provides actual results of battles involving these aircraft?

I didn't comment on his statements on his research, I commented on his statements on my research, which were intellectual dishonest.

The question you in your function as moderator should be asking Joeb is:

- Why are you making up things about HoHun's "canned software" you can't possibly know?

You might also want to ask "And why are you lining your statements with thinly veiled insults like

- "these questions aren't solved (or shouldn't be to anyone who is thinking) by making a few inputs into canned software and throwing up a graph."

There is just one thing I need to know from you now: Is the kind of insult Joeb posted tolerated on this forum or not?

Kind regards,

Henning (HoHun)

 

[FLYBOYJ]

There is just one thing I need to know from you now: Is the kind of insult Joeb posted tolerated on this forum or not?

Kind regards,

Henning (HoHun)

I don't think JoeB's comment was an insult and if it was meant to be, I'd be dealing with him as well. As you said, he doesn't know how you het your figures - why not provide that (or a portion there of) and reply "so much for canned hardware?"

 

[drgondog]

I too would like to see the math, just to appease the others here....

Dan - I suspect that Ho Hum is both familiar and conversant, with the practical Flight Mechanics equations often used, and approved for, teaching pilots and students the fundamental principles of Aerodynamics.

If that is what he is using they are reasonable within a band of uncertainty due to lack of specific and proven data values - in general comparisons. The Thrust = Drag derivative has been cussed and discussed many, many times in this forum.

I went through the same process in attempting to build a similar level turn and climb performance model - until I realized I would never be able to validate Parasite Drag values over many different speed and altitude ranges - and the thrust (THp) values over a range of Hp values by altitude are hard to come by.

So, 'reasonable' approach to reasonable accuracy falls apart at the very beginning in these long winded debates.

 

[Glider]

Hi Flyboyj,

>Well Henning, maybe he should, but does that make any of his less significant when he provides actual results of battles involving these aircraft?

I didn't comment on his statements on his research, I commented on his statements on my research, which were intellectual dishonest.

The question you in your function as moderator should be asking Joeb is:

- Why are you making up things about HoHun's "canned software" you can't possibly know?

You might also want to ask "And why are you lining your statements with thinly veiled insults like

- "these questions aren't solved (or shouldn't be to anyone who is thinking) by making a few inputs into canned software and throwing up a graph."

There is just one thing I need to know from you now: Is the kind of insult Joeb posted tolerated on this forum or not?

Kind regards,

Henning (HoHun)

An observation.
Henning you are the one who produced turn charts that showed the Beaufighter matching and beating the La5 and Fw190 and the Fokker G1 turning inside the Zero and the Ki43 not anyone else. These outcomes would raise a question mark to anyone.

Re the canned software. You have also produced graphs that showed the drop of various weapons over differing ranges. However you spoiled your pitch when later you showed a total lack of understanding of the most basic aspects of ballistics. The only way you could have produced such graphs, is by the use of canned software or the most blatent guesses.

The thing is that there is no shame in the use of such software, I have used similar software/tables in target shooting a direct comparison to your ballistic tables a lot of people do. The sad thing is trying to pass it off as all your own work.

 

[HoHun]

Hi Flyboyj,

Thanks for providing the answer I asked for, even if it was unsatisfactory.

Kind regards,

Henning (HoHun)

 

[FLYBOYJ]

Hi Flyboyj,

Thanks for providing the answer I asked for, even if it was unsatisfactory.

Kind regards,

Henning (HoHun)

Unsatisfactory to who? You? Are you going to rant off in one of your little tizzies now?!?!? As stated, you need to relax. Your participation here is appreciated but I am sick and tired of seeing your little rants and pouts when someone disagrees or challenges you, so with that said the next move is yours, however if you don't tone down the BS you will be dealt with. Now I hope I made myself abundantly clear satisfactory to your likings or not.

 

[lesofprimus]

Henning, why not just come clean with how and what u use to gather the data u present in ur excellent charts and quiet all the naysayers????

I for one would love to see how its tabulated and converted into the hard data....

 

[FLYBOYJ]

Henning, why not just come clean with how and what u use to gather the data u present in ur excellent charts and quiet all the naysayers????

I for one would love to see how its tabulated and converted into the hard data....

And I agree as well....

 

[Matt308]

As an engineer by profession, I demand it. Show your cards, Henning.

 

[HoHun]

Hi Les,

>Henning, why not just come clean with how and what u use to gather the data u present in ur excellent charts and quiet all the naysayers????

Well, here it is as a parting gift ...

Regards,

Henning (HoHun)

 

[Njaco]

A few points that might or might not help - maybe get back on track alittle....

from The Checkertail Clan by Ernest R. McDowell and William N. Hess,

pg30....
"It (The 325th) had flown (by August 1943 - my addition) 110 missions, 3,233 sorties, shot down 128 enemy planes and lost only 34 P-40s. This was kil lratio of about 4 to 1....."

pg34
"'Hoimann', a liberated Me 109G, that the Group had obtained....served an important purpose as a confidence builder. By flying with it younger pilots could be shown how easy it was to get on the tail of a 109 in a turn, if the turn was tightened up. The 109 would just go over the top of a turn on the outside and spin out..."

 

[Vincenzo]

that points were already show

 

[drgondog]

Hi Les,

>Henning, why not just come clean with how and what u use to gather the data u present in ur excellent charts and quiet all the naysayers????

Well, here it is as a parting gift ...

Regards,

Henning (HoHun)

Comments - In third person reference as if you have left us in a huff.

Best doumented methods I have seen in a very long time. If I spent a couple of months I might be able to duplicate similar rigor with respect to not only the equations and variables, but also the limitations. I have identified a couple of areas that might be interesting to debate. I might debate compressibility effects 'dismissal' for high performing fighters at altitudes above 20,000 feet.

Critical Mach occurs when Cd as a f(M) increases .0020 and this is the start of typical Drag Rise (ref RML7C24 "effects of combination of AR and Sweepback at high subsonic mach numbers", A.A. Adler 1947

He well dentifies the 'gotcha's and the very difficult, unimpeachable, data points which usually must be 'swagged' such as Oswald efficiency, true Cl max particularly for turns, reynolds number effects to Cd0 as the aircraft reduces level speed maximum to turning speed sustainable, etc etc. I identified a lot of such issues in several above posts - both here and elsewhere.

Calculating variations to propeller thrust as different airframe speeds and angles of attack, symmetric and asymmetric flight conditions, caculating a 'close' Clmax for a high G sustained level turn in which elevator and rudder deflections are large, upwing and down wing CL are 'different due to aileron deflections and slat deployments, major changes to lift related drag components for such conditions as well as major changes to Cd0 in the same manuever life cycle ---- are way beyond Excell spread sheet models.

Net - damn good science, speculative application of assumptive values, good identification of variables and influences to theory, and very difficult validation opportunity for turn manuevering for many of the plots he has presented. At least climb can mostly be assumed in a symmetrical flight and flow conditions for iterative methods to triangulate max climb for different altitudes and RN.

I suspect from the 'parting gift' comment that we are exiting stage right (but proudly, no doubt).

At any rate Ho Hun - your work product is excellent and my hat is off to you.

 

[Matt308]

Hi Les,

>Henning, why not just come clean with how and what u use to gather the data u present in ur excellent charts and quiet all the naysayers????

Well, here it is as a parting gift ...

Regards,

Henning (HoHun)

Henning that is a nice set of cited parameters for an enthusiast. And I applaud your dedication to your armchair aviation hobby. However, as a professional citation, there is zero insight into your algorithms and their applications for a specific airframe that leads to any conclusions that support your positions. Surely that is not your parting shot. For if it is, you have dug your own grave of engineering infamy on this forum.

If you do not return, have a good life. If you do, expect to have your "paper" thoroughly criticized.

 

[Waynos]

Why do some people put so much effort into trying to put some planes, whether reasonable (P-40) average (P-39) or poor (F2A) higher up the pecking order than they belong? Surely it is established fact by now that the top tier fighters of 1940-42ie the Spitfire and Bf 109 were clearly superior to anything coming out of America and that was why so much effort went into procuring the P-47 and 51. The exploits of some excellent pilots are somehow diminished when they are used to try and say that the plane (of whichever model) was better than it really was. No, the pilots were heroes, the plane (in this case the P-40) was middling to reasonable. No more no less.

 

[Matt308]

Frankly, I would agree with you, Waynos. It is the rationale for those statements that get the peanut gallery in an uproar. And that is the point of this thread, is it not?

 

[JoeB]

that points were already show

Yes, and I took pains, twice, to state that the 325th's use of 'Hoimann' as a demonstrator for new pilots, to show them they could out turn the 109 in their P-40's was *not* the single killer piece of evidence that absolutely *proves* the P-40 could out turn the 109. Again as I mentioned the second time, responding to Timppa, 'turn' or 'out turn' is a less well defined concept than say, velocity where everyone means exactly the same thing whenever 'velocity' is mentioned. Not as true with 'turn'. All that said, IMO, and I said it was just my opinion, the 325th's experience with their captured 109G would weigh more heavily in my mind than graphs of unknown provenance.

Also in general on credibility of 'stuff you read on the internet', note that the post you responded to quoted the same info I gave from the same source as I did, the McDowell and Hess book on the 325th FG. The graphs just come from, well wherever they come from. That's not to disparage original efforts, but there is a difference between a 'trust me' source and pointing to a book or other record.

What's needed to verify a calculation (I'm also an engineer by training) is to show that it's predictions agree with full scale results over the whole range of applications in which you claim it's authoritative. It's not just to present 'the math' and effectively claim everyone who can't disprove that particular math must believe the calculation's accuracy. All engineering calculations are models of reality. Whether they model reality sufficiently for all the cases in which you use them is shown by agreement to full scale results.

Again I think a difference that creeps in here is that some people's aim is really to create a virtual reality for sim games which is well defined and predictable, and not wildly out of whack with the real world of WWII fighter a/c. Their goal is not really to fully explore the reality of WWII fighter a/c, with all its uncertainties and anomalies, which may just not be suited to a single answer. And sometimes that difference in goal shows.

Joe

 

[Matt308]

Well said.

 

[FLYBOYJ]

What's needed to verify a calculation (I'm also an engineer by training) is to show that it's predictions agree with full scale results over the whole range of applications in which you claim it's authoritative. It's not just to present 'the math' and effectively claim everyone who can't disprove that particular math must believe the calculation's accuracy. All engineering calculations are models of reality. Whether they model reality sufficiently for all the cases in which you use them is shown by agreement to full scale results.

Again I think a difference that creeps in here is that some people's aim is really to create a virtual reality for sim games which is well defined and predictable, and not wildly out of whack with the real world of WWII fighter a/c. Their goal is not really to fully explore the reality of WWII fighter a/c, with all its uncertainties and anomalies, which may just not be suited to a single answer. And sometimes that difference in goal shows.

Joe

From page 13 of the "parting gift."

4.1 Limitations of historical data

Generally, when dealing with historical performance data, there are several factors
to keep in mind:

• Aircraft performance is not uniform. Engines often have several percent
tolerance, and general condition of the airframe and surface finish can
make a difference, too. Power tolerances do not carry over linearly to all
performance parameters, they are less noticable in top speed, but more
pronounced in climb rate.

• Performance tests are always partially theoretical in order to determine
the performance of the aircraft under standard conditions for comparative
purposes. Atmospheric conditions, air temperature and engine performance
could vary in reality, so the test results had to be transformed
theoretically to stand for an idealized aircraft performing under standard
conditions.

• Real-world performance tests often contradict each other. Sometimes it's
possible by using quantitative analysis methods to determine the reason
for the contradiction, sometimes it's not. A lot depends on the level of
detail given by the historical reports.

• The engine charts historically used for generating idealized performance
charts are typically based on theoretical methods themselves. They are
usually accurate for the well-tested low-altitude region, but tend to be inaccurate
at higher altitudes. This is a reflection of the state of contemporary
technology: only the wartime pressure for higher engine performance
lead to a better understanding of engine physics towards the end of the
Second World War.

 

[Matt308]

...and this specifically:

"Real-world performance tests often contradict each other. Sometimes it's
possible by using quantitative analysis methods to determine the reason
for the contradiction, sometimes it's not. A lot depends on the level of
detail given by the historical reports.
"

... "A lot depends"? In a technical document? "A lot"? If the quantitative analysis has the merit to stand on it's own, then historical reports become irrelevant. If it cannot, then the quantitative analysis is subjugated to being only another data point for discussion. Not a fact. Just another data point for debate by the masses.