Spit/109 sea level speed comparisons in 1.08 beta patch

[ATAG_Dutch]

Originally Posted by 5./JG27.Farber

I cant tell what your trying to say? - Just to add a graph? Mein Deutsch ist Scheiße

Vielleicht kannst du im schule zuruck gehen? Never mind, so's mine.

[5./JG27.Farber]

services

Engine performance DB601A

Intermittent (1 min) 1100PS at 2400 r / min 1.4 ata

Start power 990PS at 2400 r / min 1.30 ata

Climb / combat power 910PS at 2300 r / min 1.23 ata

Full pressure altitude 4000m

Farber, Bf109E-3 data, shown in Kennblatt has been obtained on 30 min Steig/Kampflleistung bei 2300 U/min 1.23 ata of aircraft with DB601A-1 'bei altem Lader'

Yes, this is TAS -Wirklich Geschwindigkeit

ok I got it. That graph is not full throttle but the limited combat setting and it also uses the old compressor which begins to loose Ata at 4500metres not 5000metres. Therefore the results are lesser than they should be in clod which seems to use the new compressor.

I wonder when the new compressor was rolled out into the field and at what rate?

[ACE-OF-ACES]

Originally Posted by Matt255

I think in that case, the pilots got different results.

Maybe.. maybe not

The point being..

Two people can read a combat report and draw two different conclusions..

Due to their background and biases

Where as..

Two people can add 1 + 1 and draw the same conclusion.. i.e. 2

Independent of their background and biases

In summary..

The problem with anecdotical evidence (aka after action pilot reports) is as follows

1) anecdotical evidence is a one sided story.
2) anecdotical evidence is written by those who lived to write about it.
3) anecdotical evidence does not contain enough info to recreate the scenario in-game.
4) anecdotical evidence is subject to interpretation.

For example of each..

WRT 1) As most of us know there are two sides to every story, and you will not find anecdotical evidence that has input from both side (axis and allied pilot) with regards to the encounter being described.

WRT 2) As most of us know a statistical result depends on the input data. The fact that anecdotical evidence was written by the pilots who lived to write about it excludes the pilots who did not live to write about it. Which makes the statistical result based on the anecdotical evidence biased/filtered towards pilots who lived to write about it. For example, assume there are 100 after actions reports describing how the pilot in his 109 out turned a Spitfire.. We don't know how many 109 pilots died while trying to turn with a Spitfire a thus un-able to write about it, was it 10, 100, 1000? We don't know.

WRT 3) As most of us know anecdotical evidence does not contain enough information about the scenario to recreate scenario in game to preform a test to see if the results are the same. That and the results in both case (real and recreated simulation) depend more on the relative pilot experience than the relative plane performance. That is to say change the pilots and you can change the outcome of the scenario. In essence you would be making changes to the flight modeled based on the relative experience of the pilots not the relative performance of the planes. This is why they did testing under formal and controlled conditions. (see sig)

WRT 4) As most of us know people are different, and therefore peoples take on events will be based on their life experiences. That is to say two people can read the same anecdotical evidence and draw to very different conclusions. Ask any cop who has interviewed several people who have witnessed a crime and they will tell you how peoples perceptions of events can vary. Where as 1 + 1 = 2 is not open to interpretation. (math ftw)

PS in each statement above, there are no absolutes! To improve the readability, in this post I removed my previous qualifying text where I said things like 'typically this' or 'typically that' or 'you will be hard pressed to find'. That is to say, you may be able to find a couple of cases where both an axis and allied pilot had input to an after actions report, but this exception to the rule does NOT change the rule. Also note, I am not saying math is without error, only that math is your best hope of being on the same sheet of music, in that it removes most if not all human bias and interpretation errors. In short, given time, you can track down the source of math errors, where as even with all the time in the world you would still be hard pressed to track down the source of human bias and interpretation errors!

[notafinger!]

Comparative performance between the major single seat fighters from "The Most Dangerous Enemy" by Stephen Bungay.

[ACE-OF-ACES]

Originally Posted by "The Most Dangerous Enemy" by Stephen Bungay

Turning circles are as calculated by John Ackroyd of the Manchester Schoold of Engineering

That is a strange looking turning circles graph..

Altitude vs. Radius?

Where alt units state ('000 ft)

Something is strange here.. as in some info is missing (calc at a fixxed speed?)

I mean based on that graph the Spit is not able to go above 700ft in alt?

At a glance one might conclude that the Spit and Hurry have better turn radius..

But it is allmost as if that was done on purpose..

Does the book say more about that graph and how Mr. Ackroyd calculated it?

[NZtyphoon]

Originally Posted by ACE-OF-ACES

That is a strange looking turning circles graph..

Altitude vs. Radius?

Where alt units state ('000 ft)

Something is strange here.. as in some info is missing (calc at a fixxed speed?)

I mean based on that graph the Spit is not able to go above 700ft in alt?

At a glance one might conclude that the Spit and Hurry have better turn radius..

But it is allmost as if that was done on purpose..

Does the book say more about that graph and how Mr. Ackroyd calculated it?

At first glance I though the altitudes were reading as 600,000 to 900,000 ft -

shades of the Dr Who Spitfires!

[ATAG_Snapper]

It appears the Turning Circle chart is poorly presented. It's not an X-axis/Y-axis graph at all that I can see. It's simply drawing the turning circle arcs showing the relative diameters; all at "000 ft" which I take to be sea level.

Secondly, have a look at the relative speed charts between the Hurricane I, 109 E3, and the Spitfire I. The speed curve for the Spitfire I looks remarkably like the one for the much-decried "Über Sissyfire IIa" in the current retail version 1.05, as does the curve for the E3 to the CoD v. 1.05 E3, and, by gosh.....there's JTDawg's old Rotol!!!!!

Obviously that chart is wrong and the author sadly misinformed.

[Crumpp]

Obviously that chart is wrong

Typical....

Most of these history are written by amateurs who know very little about the science of aircraft.


I think the author is a Management consultant.

[ATAG_Snapper]

Originally Posted by Crumpp

Typical....

Most of these history are written by amateurs who know very little about the science of aircraft.


I think the author is a Management consultant.

No doubt. Barely able to tie his shoelaces, I should think!

[Crumpp]

I did not say the guy was stupid, Snapper. He is very intelligent and well respected. He has also written some good books.

He is not an aircraft performance engineer or an aerodynamicist.