Absence of evidence does not equal evidence of absence.

The double standard you have. Minimal, actually next to nothing, when it concerns your beloved Bf109 of nazi Germany and evidence to the nth degree when it comes to anything to do with the British.

I really don't understand the desperate need to deny that most, and probably all, fighter command aircraft were using 100 octane fuel during the BoB. There is more than enough evidence to show that the change to 100 had been authorised well before the BoB, there were more than enough stockpiles, the conversion process was simple enough by RAF servicing standards of the time and it was in widespread use from combat and Squadron reports.

It would have been ridiculous for the RAF, with all the stocks available, to have only transferred some units to 100. Why would they do that when they were at war and expecting invasion? The only delaying mechanism would have been the mechanical modification of engines which was simple enough and carried out during servicing. New engines were delivered already converted. It would have been more ridiculous to suggest it wasn't available to the units facing most of the fighting and not very sensible, with the rotation of Squadrons with their aircraft, not to organise the support of 100 octane for those aircraft while on rotation.

I suspect that some people either want to unhistorically 'castrate' the RAF as someone suggested or they are just Trolling.

Regarding Blackdog's ideas for missions, I have no problem with representing fuel shortages following bombing of production plants etc but that is a seperate issue. It never happened to the point that fuel bacame a problem but a 'what if' is fine by me, that's what missions are built for, it isn't all re-enactment.

Please note that I have not made a statement towards or against the subject of 100 octane fuel. I simply said the style of some posters here kills any meaningful discussion of any type and creates more bad blood. Just to make that absolutely clear.

Yeah easy. Simple. Quick. And all that in the middle of a ragging war when bomber units where painfully in needs of more power for take off as their aircraft were fitted with the absolute essential war-weary equipments they lacked before. And Hurricane units (the most numerous aircraft) were fighting hard the gap btw their mount and the fast flying germans bombers.

It makes no sense Klem. No a single notch of it. It's an illusion for late grown child tht prbably started somehow reading two line in an history books.

I love the Mayas civilization but I am not convincing myself Steve Job and the NASA were their creation

Guess why the 21st century RAF can't introduce a new fighter without so much pain ?

IMHO : You'd better help the devs to fix the Spit FM toward some realism at least. I am sure that they would then be happy (and with some financial interest too) to give you your boosted Merlin on Spitfire

Klem- i've just gone through that forum thread you posted the link to http://www.ww2aircraft.net/forum/avi...2-a-20108.html
I'd say that nails it- credit must go to MikeWilliams and Glider for their research efforts- the weight of evidence clearly affirms the fact that 100 octane fuel was widely used by RAF fighter command since early summer 1940.

As for the tone on that forum- it's a marked contrast to the personal insults that get thrown around here.

+1 couldn't agree more. Hats off to the guys researching and posting links to their sources.

Unfortunately I do not show any double standards, and have never claimed anything in excess of the available evidence seen here in detail http://www.kurfurst.org/, which you seem to consider minimal and next to nothing, even though 360 000 pageloads tends to disagree with your assessment.

You seem to be desperate to give some meaning to your life by randombly kidnapping threads will all sorts of your unrelated and incoherent hysterics like 1,98ata on late 109s, a question that I am afraid has been decisively set straight long ago.

Well its rather simple, I would have believed even with a blindfold one would easily get it. The standard fuel in the RAF was 87 octane, and from around March 1940 we have a British document saying that 100 octane fuel replaced it in select fighter stations. No, it doesn't say all, it specifically says: "the fighter stations concerned".

That seems crystal clear I am afraid.

And, despite literally years spent desperately by some to find something to the contrary, there's an utter inability to produce a primary source even hinting universal use; Spitfire manuals from the summer of 1940 still continue to mention both 87 and 100 octane ratings, the fuel consumption figures of the RAF clearly show that 2/3s of the avgas consumption was 87 octane, research in Australia found a paper that clearly noted RAF FC had not managed to fully convert until November 1940; the utmost Spitfire authorites has noted the fears of 100 octane supply due to tanker losses and the U-boot threats.

Most of us find it difficult to ignore all of that, unlike you. And just because you continue to use loud rhetorics in otherwise hollow and childish posts, its not gonna change.

Which part of 87 octane being the standard fuel in the RAF FC prior the spring of 1940 and that afterwards select fighter stations were receiving 100 octane fuel were you unable to decode?

I don't take orders from you I am afraid. ;)

I'll stick to the written sources of the time rather than the wishful thinking of todays gamers.

You do the ground crews and engineering personnel a great dis-service when you suggest they couldn't manage it 'in the middle of a ragging war'. Perhaps you are judging them by more casual peacetime standards.

If you can't make even a notch of sense from the reports you have been shown I can only assume you are suffering from the same wishful thinking that dogged Hermann Goering.

Like some other anti-100 posters you choose not to believe the evidence of the time that is presented. I can't change that and I'm not going to bother trying any more.

btw, if your 'late grown child' was a reference to me you couldn't be more wrong.

+100

Pls Klem edit your post. Hugely discomforting to read.

"The late grown child" was nothing as an insult.

Moreover I didn't say that there wasn't 100 oct. I say that there is no link that the FC was converted and it does not make any sense in an air defense campaign.

Let's take the biofuel swap of modern aircraft engine. It makes sense to test and add the use as a strategical resource for short high intensity conflict. That's why all major airforce today want to show others they have that possibility. Does it means that the USAF will convert its fleet of F15/16/22 to BioFuel ? Yeah as much as they want starving soldier on the battlefront...

You've got to get an eye on the purpose of an application. From time to time of course, there is no thinkable application for a reasonable mind.

lol.

Originally Posted by TomcatViP
Moreover I didn't say that there wasn't 100 oct. I say that there is no link that the FC was converted and it does not make any sense in an air defense campaign.

:confused:

TomcatVIP perhaps there is a language problem here.

My previous post was a response to the way your post read. You seemed to be saying that the RAF did not have had 100 octane in wide use in FC and in your last post you say there was no link that it was converted but there are many links to show it was. You also say that it does not make sense to use it in an air defense campaign but what better time than when fighting for your life?

Your modern comparison with the biofuel example has no relevance in this argument. The RAF wasn't interested in showing it could use 100 octane for any propaganda or political purpose or as a standby fuel. It needed it, it had it and it used it. The "purpose of the application" was survival not merely a demonstration of capability.

I sincerely don't understand why a 'reasonable mind' cannot accept the documented evidence of the time showing widespread use. However, let me offer a suggestion. Let us suppose that not ALL of FC was converted for the BoB. Do you seriously believe that the fighter stations in the South East of England, facing almost all of the combat flying, would not have been equipped with 100 octane fuel when so much was available and the conversion process was fairly simple? If you want to say that the stations in Northern England may not have had 100 octane I am happy not to argue that point because they do not exist in CoD.

btw I am sorry if my reference to Hermann Goering was discomforting but it was precisely wishful thinking and ignoring or not gathering accurate intelligence that led to his poor conduct of the campaign. I felt it was a reasonable and relevant comparison with the views that wish to ignore documented evidence. Perhaps I should just say "believe what you like, we have 100 octane" (or we should have).

Anyway, if you still hold to your views and I still hold to mine there's no point in carrying on the discussion. I wish you well.

I wouldn't bother to much Klem, i pretty sure some of the people here are members of this,

http://theflatearthsociety.org/cms/

;)

So you admit you can't produce evidence for even a single combat sortie by a BofB RAF FC Hurricane and Spitfire using 87 octane.

Same as you can't PROVE that there wasn't one.

Then why is there abundant evidence showing widespread use of 100 octane, and literally dozens of memoirs and histories showing the use of 100 octane, and many individual combat reports showing the use of 100 octane? Why are there no memoirs or squadron level or individual combat reports stating the use of 87 octane fuel?

I can't prove something that didn't happen, and there is NO evidence showing 87 octane fuel use during Spitfire or Hurricane combat sorties during the BofB.

There is evidence for widespread 100 octane fuel use during Spitfire or Hurricane BofB combat sorties , but no evidence of Spitfire or Hurricane combat sorties using 87 octane.

I think the some RAF fliers are done with that Thor. What we see now is a reaction because the last series was spoiled by individuals with an agenda and the devs bent over. This time, with more detail and with the same old hands more educated in terms of flying and historical knowledge, we see the Spit drivers stand up because they don't want it to happen again. Already we have some calling the Spitfire a UFO - these people can go to hell. I notice that these types never seem to mention the horrendous DM of the 109 though, for example.

I think I speak for practically all of the RAF jockeys when I say that I want accuracy even at the expense of the RAF, I hate to see this very vocal minority do the rest of us such a dis-service.

What are these types going to do when the DM is patched? They'll piss and moan rather than realise that they aren't super-pilots and need to fly a different way.

It's called the "big lie" Osprey.

Repeat the same misinformantion often enough, and loud enough, and it will eventually be accepted as truth.

At least on gamer forums like this.

On real historical aviation forums this kind of behavior usually results in being laughed off the forum, or an outright ban.

Right Issy?

It used to be like here, until they banned Kurfurst for the same as what he tries to do here. (I am not joking)

See my above post.

Would this be that paper what Glider asked you to produce and you couldn't? That others made efforts through their records office contacts on your behalf and found nothing?

@ElAl, yup, got it.

The important thing is we get this message across to the development team though, if that happens I couldn't give a rat about what Kurfurst and co believe.

There's tons of circunstancial evidence that the RAF converted the Spitfires and Hurricanes. Loads of it.

A couple of things to also think about..

1. The modification to the boost cut out control that was needed was (AFAIK) one way, once done it meant you couldn't put 87 octane into a converted Merlin
(This is my understanding of it, correct me if you know better :))

2. At the time of the changeover the RAF painted '100' next to the fuel filler cap to ensure that the correct fuel was put in. I have literally hundreds of photographs of BoB Spitfires and I have yet to find a photograph taken during the BoB that shows a Spitfire or Hurricane with this feature, which suggests to me that the need to differentiate between the 2 types of fuel was no longer there, ie. all converted.

Also several RAF pilots state in their memoirs that the conversion took place 'just before' the BoB proper, Tim Viggors, Pete Brothers, Al Deere are recent ones I've read.

See it this way: Back in the Il-2 days Oleg Maddox was accused of having no patriotism for making german aircraft too good vs the soviet types by the russian communities while he was accused of making the soviet types too good and the germans too bad by the germans. Oh and he was also accused of being a "damned commie" by the US community and of not having the slightest idea about history by the RAF fans because some types never made it into the game. So if everyone complained there must have been something right with the game ... ;)

I think it is a bit far fetched to say that the RAF types are modeled the way they are because of the lobbying of a few loud people. That gives them much more influence than they really have. But ...
It's one thing to vehemently defend the evidence or documents which point to the RAF using 100 octane fuel for its fighter squadrons (which I, as a LW-centered player with an avid interest in military history agree with). But I have also seen several discussions being more or less successfully derailed by the same outspoken RAF fans once the subject of german performance, and especially the question of the DB 601N equipped types, was mentioned. People may have their personal interests, that's fine and normal, but it must absolutely not lead to them wearing blinders and red/blue-tinted glasses which doesn't allow them to be impartial anymore. Being a fan is one thing, being a fanatic is another.

I have read loadsa memoirs from BoB pilots and have NEVER read anywhere in any of them about a pilot complaining along the lines of "Ran into a bunch of 109s/110s and couldnt catch them because we were using crappy low octane fuel".
I think if any BoB fighter squadrons in 11 group had been forced to use the low octane juice there would of been a stampede of squadron leaders knocking at fighter commands door complaining, and if that had happened and the prime minister (who had a full understanding of the importance of the BoB) had heard about it heads would have rolled.

Arghhh I really didnt want to get into this troltrap,I wish I hadnt posted but when someone is wrong on the internet you cant let them get away with it can you .

Yes the very same I was referring to, although the full story goes that I have referred Glider to the findings of an Australian guy going under the handle Pips who posted the summary of this paper several years ago on butch's board. BTW Neil Stirling was also participating, but he keeps dead silent about this paper on his site propagating 100 octane use.

Now, despite being perfectly aware that he needs to contact this Australian guy, Glider kept b!tching to me about producing the paper, of which I have only seen a summary on a board. I kept telling him to contact Pips and ask him.

Instead, Glider kept asking me, living 10 000 miles from Australia to produce the paper found by an Australian, in Australia.

Then I gave Glider the URL to the discussion where this was posted. At first he claimed "he could not find the alleged discussion", then went back asking me, living 10 000 miles from Australia to produce the paper found by an Australian, in Australia.

After a while Glider gave up this tactic of dismissing the paper, and claimed he contacted the Australian archieves, but the Archive said they've never heard about it, and again went back asking me, living 10 000 miles from Australia to produce the paper found by an Australian, in Australia.

Lastly, Glider reproduced the email reply of the Australian archive staff, who in reality replied to Glider's vaguely worded email (somewhere along the lines 'gimme the paper of 100 octane') that given such inaduquate reference that he gave, its not possible to find it and he should supply accurate and precise reference so they would try to dig it up.

You may have already guess that after that Glider went back asking me, living 10 000 miles from Australi, having seen but a summary of the paper on a discussion board and giving him all details I've known about, a to produce the paper found by an Australian, in Australia.

At that point I believe it's understandable that I came to the conclusion that, for entirely subjective reasons, it may not be possible to have a fruitful and rational discussion on the matter with Glider.

Then you came into the picture and told your (half-)story, and so I've told mine, and now people can make up their minds about you, Glider, and the concept of credibility. ;)

Right. And that's is why I was never banned from a real historical aviation forum, and that is why you have been never been a member of one, or have the slightest idea how a discussion would look like between people with real interest in combat aviation and an open mind, regardless of nationality. ;)

No, I didn't. And as others have pointed out, if you want to prove that RAF fighters ran on nothing but 100 octane, you should bring the evidence for it, not asking me to disprove your unsupported theory. ;)

if you want to prove that RAF fighters ran on a mix of 87 and 100 octane, you should bring the evidence for it....

Round and round we go..

So can you give me a definite number of 87 octane fighters used by the British between June and November 1940? To prove your theory.

No, you can't. So you're in exactly the same situation as the people you're asking evidence from. Except that you're being hypocritical. your theory is exactly that, a theory.

There is no black and white!

There is evidence that selected squadrons where supported with 100 oct.

There is NO evidence that ALL squadrons where supported with 100 oct.

There is a grey zone, or maybe schroeders cat, which isn't, and can't be, defined.

The compromise solution might be that the overwhelming majority did use 100 oct.

Agreed.

I think people will be more than happy with this, because then the mission builders can decide, and people can vote with there feet.

So we need a hurri and a spit mk 1 with 100 octane fuel as well, as the 87 octane versions we already have.

Everybody happy?

No, not happy at all.

All the evidence indicates that 100 octane fuel was ubiquitous in Fighter command during the Battle of Britain. The only 'evidence' to the contrary is one unverified document that allegedly existed at some time in an archive in Australia, that now cannot be retrieved. There is unfortunately no copy of it anywhere and repeated requests by members of other forums to be shown evidence confirming the existence of this document have come to nought.

The British had determined to use 100 octane fuel in aeroplanes in 1938 (despite the technological hurdles confronting them in refining the stuff). Sufficient advances in techonology were achieved such that by later 1939 the decision was made to standardise Fighter Command's fuel to 100 octane. Conversion took place throughout the early part of 1940, to the extent that it was considered standard by March/April 1940. By July 1940, when the BoB was beginning, it was a done deal.
Conversion for the remainder of the RAF (bomber and coastal command) was ordered in late 1940 but not completed until early 1941.

To insist on placating a person who has a contrary belief despite the lack of supporting evidence for their view is pure folly.

As Geoffery Lloyd, the minister for 'Fuel and Power' in 1940 later said in answer to a question put to him in 1944 'Do you think 100 octane was the deciding factor in the Battle of Britain in 1940?', he replied 'I think we would not have won the battle of britain without 100 octane- but we did have 100 octane'.

There is a black and white dicotomy:

White: There is evidence for numerous combat sorties by BofB Hurricanes and Spitfires using 100 octane fuel.

Black: There is NO evidence for even a single combat sortie by a BofB Hurricane or Spitfire using 87 octane fuel.

There is NO grey zone, because if there was, there would be evidence for combat sorties with 87 octane fuel along with 100 octane fuel.

Theory: 100 octane was used exclusively by front-line RAF FC Hurricanes and Spitfires during the BofB.

Theory predicts that combat reports would be uncovered showing 100 octane use. These reports exist and have been brought to light; the theory correctly predicts the evidence.

Theory: 87 and 100 octane was used by front-line RAF FC Hurricanes and Spitfires during the BofB.

Theory predicts that combat reports would be uncovered showing 87 octane use. These reports do not exist, and none have ever been published.
The theory fails the evidence test.

WOW.. That brings back memories! ;)

As long as there's a 100 octane spit mk 1 and hurri in game, i'm happy, which even the most vociferous naysayers admit were there in some numbers.

As to whether they all were or whatever, the nay sayers won't change there mind, but it will be irrelevant, and they can argue till the cows come home for all i care.

Mission builders can build as they see fit.

As long as we get the 100 octane spit and hurri.

My issue is not really about the game in this discussion- if the game developers want to even up the competition between red and blue by compromising elements that's their call. I'll still play it.
Want i dont want to see happen is people altering historical facts.

As Captain Rum said in Blackadder when challenged about not having a crew a aboard his ship:
Blackadder- 'I was under the impression that it was common maritime practice for a ship to have a crew'
Rum:- 'Opinion is divided on the subject'.
Edmund: 'Oh, really?'
Rum: 'Yes. All the other captains say it is; I say it isn't'

People have been doing that since history began.

I like you see all the evidence thats been presented to show only one thing, but there are some here that won't change there mind for whatever reason.

However, since even the most vocal naysayers admit that there was hurris and Spit mk1s using 100 octane fuel in some reasonable numbers, they need to be in the game period.

As long as the devs get that, the rest is just immaterial to me, people believe strange things, after all some people still believe the earth is flat....

There is a lot of interesting data and facts regards the octane rating and I have enjoyed reading through them, But, the simple truth is that a Rotol Spit Mk1a, as modelled, is slower than a Rotol Hurricane and the 6Ilbs of Boost does sweet FA to boot! - That's about as 'Black and White' as it gets - there is no 'grey' area in that simple observation!

Even if not completely perfect, relative performance of all the fighters is the essential fix for me (for the time being anyway....except having 6Ibs of boost working is better than no Boost)!

+1 signed. I believe, along with a more smooth running game (if possible) updates and fixes to the planes on both sides of BoB, where required, are a necessity.

If we are still debating (I mean hearing each other arguments) I wld say that Spit FM need to be fixed... Then the matter of 100 or no 100 won't be such a question. [/SradfordUpAvon_Mode=OFF]

As MG already said, that FM's and DM's would be fixed/revised with the next patch, i'd like to say, any discussion of FM/DM before that is a pure waste of time

Possibly. I haven't looked into it but perhaps the 'undermodelling' of the Spitfires is because they are modelled with 87 Octane?

Hmm, Spitfires being undermodelled. Interesting.

Klem, may I ask you to try something.

Pick a Spitfire II.
Bank it 90 degrees.
Pull back the stick fully forward.

Come back here and share your observations about it. :D

How does one pull back the stick fully forward?

"Spitfires" as a whole are not undermodeled. I'll agree that the Spitfire Mk.1 is underperforming, but not because of "87 octane".

This is what I was trying to get at earlier in this thread. People misunderstand what the octane number actually measures.

:rolleyes: I think you know what he means.

Frankly I am not sure about them. Do they (Mark Is, they seem to be modelled with 87 octane boost levels) not meet specs for a 87 octane one? Climb too slow? Or..?

No.
Couple of months ago i compared the www.spitperformance.org graphs with the game speeds (here). The graphs show the 6lbs boost (with 87 oct. fuel) speed of Spitfire. The 109 would be faster, but not that much – if we look at the proportions of course, because now the 109 is slower than it should).

Thanks tom, it was just a thought.
(I think this is the link you meant http://www.spitfireperformance.com/spitfire-II.html )

================================================== =

@Kurfurst. Sorry if I was not clear. I was talking about the Spitfires that are universally claimed to be "underperforming", these are the Spitfire I and Ia. I did not mean the Spitfire IIs.

I did some quick checks on the Mk II a few months ago against the MkII report linked above. I couldn't get it to fly as fast as the report stated but it was very close, just a couple of % under. Mind you I was pretty crude about it, as it meant thrashing the engine at the maximum boost I could make at that altitude (the report suggests +9lbs boost was used) and eventually it broke. So not to be taken too seriously and probably also impatience on my part. Results:-

Alt Boost RPM ASI mph ASI in report
6500 +5.3 2990 280 between 306 @ 5,000' and 326 @ 10,000
10000 +5.3 2990 280 326
15000 +6.2 2990 270 345
(on another run at 10,000' I seem to have written down +5.3 and 290 mph {?!} )

All below the reported data but of course I could not get +9lbs boost.

You may find this site interesting. I can't vouch for its accuracy butit looks pretty good to me.....
http://www.spitfireperformance.com/
http://www.spitfireperformance.com/spit1vrs109e.html
You can see from the level speed chart why we want the 100 octane - and I can understand why you would not be happy about that. By the way I have read several bio accounts of how, in the BoB, the 109 would escape in a dive but on occasions it was possible for the Spitfire to catch them in long chase.

Incidentally on use of 100 octane fuel, I know we seem to have agreed to disagree but that last link contains the following ...

"As of 31 March 1940 220,000 tons of 100 octane fuel was held in stock. The Co-ordination of Oil Policy Committee noted in the conclusions of their 18 May 1940 meeting with regard to the "Supply of 100 Octane fuel to Blenheim and Fighter Squadrons" that Spitfire and Hurricane units "had now been stocked with the necessary 100 octane fuel". The Committee recorded that actual consumption of 100 octane for the 2nd Quarter 1940 was 18,100 tons.

Jeffrey Quill recalled:

It was only shortly before the Battle of Britain that we changed over to 100 octane. It had the effect of increasing the combat rating of the Merlin from 3000 rpm at 6 1/2 lb boost (Merlin III) or 9 lb boost (Merlin XII) to 3,000 rpm at 12 lb boost. This, of course, had a significant effect upon the rate of climb, particularly as the constant speed propellers (also introduced just before the battle) ensured that 3,000 rpm was obtainable from the ground upwards whereas previously it was restricted by the two-pitch propellers. It also had an effect upon the maximum speed but this was not so significant as the effect upon rate of climb."

What is interesting apart from the date by which FC was converted is that quarterly use was 18,100 tons against a stockpile of 220,000 tons. There was no shortage.

Klem, he's seen all of that but he just isn't interested. Tom's post is interesting, I will have to read more on the top speeds since I am quite surprised that the 109E-1 is marked @ 302mph vs the Spitfire 283mph. I know it's @SL but that is rather a lot.

I'll answer all in one post if you can stomach it ;)

I oppose all types who argue this. I don't get involved in the DB601 argument because I don't know anything about it. Show this evidence and I'm sure you'd get support from the likes of Klem, Al Sch... etc and myself here.


Just to understand you then. You are dismissing a multitude of documents which have been produced in various forms from the time in favour of a single one which you cannot produce on the basis that the person who didn't believe it but tried to get it, couldn't, and neither could you?
Seriously Kurfurst, do you not see the gaping hole in your argument? I'm not kidding when I say this but continuing with logic like this generally ends up with the propagator being called a lunatic. Is it just really because you are unable to accept that you are wrong or is there some other reason? You can't use the same protocol which courts of law use, there is no innocent until proven guilty, it's perfectly acceptable to use circumstancial evidence if there is enough of it.


What exactly will this prove? That the Spitfire out-turns the 109? It does.



I'm presently reading "A Willingness to Die" by Brian Kingcome, his memoirs. He was a frontline BoB Spitfire pilot for 92 Squadron @ Hornchurch. Last night I read, on page 123, chapter 5, "The Phoney War and The Real Thing" he writes "slowly we reverted almost to a peacetime routine, time of year and sunset permitting, we usually ended our day with a beer or so in the mess before setting out on a pub crawl, pooling our petrol coupons or occasionally filching the odd gallon of 100 octane aviation fuel from the bowsers at dispersal.". This was during the phoney war, BEFORE the German invasion of France.

Has anyone bothered to log the TAS, Altitude, Throttle setting, etc in real time to a file during the CoD spitfire test flight?

And than compare that data to the real world data?

If not I would highly recommend that you do, because based on my experience most of the 'errors' people argue about are pilot errors during the test flight, not FM errors.

And the only way to be sure of that is to log said data in real time during the entire test flight, because something as simple as not holding a steady altitude during flight can have a big impact on the speed values.

From the history of Trimpell Oil Refinery - Heysham. I'd love to know where they got the '384 Spitfires converted' from, would be interesting to find out.


The site was set up in 1939 as the Heysham Aviation Fuel Works to produce aviation fuel for the RAF. Using coke brought in from the Durham coal field together with imported gas oil, ICI produced the base petrol and ammonia while Shell produced iso-octane to boost the base petrol from 87 octane to 100 octane standard. Shell had found that the use of tetraethyl lead and hydrogen as fuel additives made it possible to suppress engine knock and to boost aircraft engine performance.

The plant at Heysham, together with those at Stanlow and Billingham produced iso-octane additives required to raise 87 octane fuel to 100 octane rating. Initially, the limited size of the 100 octane fuel stockpile required strict rationing until supplies could be increased to meet requirements and the 100 octane fuel was dyed green to distinguish it from the 87 octane fuel which was blue.
Bulk supply contracts for higher octane fuel were placed by the Air Ministry and it was put into widespread use in the RAF in March 1940 when Spitfires' Rolls Royce Merlin engines were converted to use the 100 octane fuel.

By May 1940, reconnaissance Spitfires had begun flying combat missions using the 100 octane fuel. By 31 July 1940, there were 384 Spitfires serving in 19 squadrons using the 100 octane fuel.

Yes, this site.

That is not even the top speed. Only 1:32 ata boost pressure ("climb and combat power"). The maximum performance ("start and emergency power") is 1:42-1:45 ata. This would be an additional 150-200 PS (~15-20%) engine power...

According to Dowding there were 19 Spitfire squadrons in RAF FC on July 08 1940:

http://www.ibiblio.org/hyperwar/UN/U...ette/37719.pdf (p4560-61)

but I'm not sure where the 384 figure comes from.

This forum is interesting from the history discution. Some +12 data is really nice! Its to bad that so much RED vs. BLUE bs.

After the new patch we should do some testing.

It would be nice if more people did before claiming the FM is too this or too that..

But I fear that will never will happen..

Which is why I decided to make my own website dedicated to performance testing, i.e.

www.flightsimtesting.com

Where I have created an online version of IL-2Compare, which allows you can compare one plane to another.

Right now all I have is IL-2 data..

But I am working on posting CoD and real world data..

Than you will be able to compare 'game' data to 'real world' data side by side in real time.

Basically all the stuff I have been doing for the past 10+ years in print outs people will be able to do in real time onilne.

Wow great !

thx I will be a frequent visitor. You'd better assign a chair to my name in some corner ;)

Hi. The conditions were ideal for the game, so we get the best results - this can only get worse if there was disturbing circumstance. That was the maximum speed that I could reach.

I had same settings during all tests.
Realism settings: full real. Weapons, fuel, weathering was default (can't change anyway).
Quick mission: Bomber Intercept Low, without enemies. Altitude: 0-50m over the Channel, time: 12:00, i dont know the wind. All speed IAS.

I slowed down the aircrafts at the start, then full gas. Trim tab set to level flight (without ascent/descent of course), the radiators was open as needed, and no WEP. Variable Prop Pitch set to max constant speed (had to experiment with this, but the results are all maximum, constant speed).

Are you tested them? You have different values​​?

Consider it done! ;)

Hey!

Not 100% sure yet if the 'ideal' conditions in the game equate to 'standard atmosphere' conditions.. Which is what all real world data is converted to, unless stated otherwise. I am pretty sure the 'ideal' conditions are not 'standard atmosphere' based on some of the temps and pressures I have seen thus far.. But the good news is it is a simple mater to convert the CoD data to 'standard atmosphere' conditions, by using the same methods they use to convert real world data

That is the way to do it.. Stick with the same conditions for each test.

Now all you need is to go to the FMB section, talk to Altros and ask him for the C# file that will allow you to log the flight data to a text file as you fly the mission, than you can use that data to verify the test methods (read how you fly) and once that is verified as correct you can than convert the data to standard atmospheric conditions and compare it to the real world data.. Or wait a few weeks until I get my website done! ;)

I have been doing some CoD testing.. But I have been more interested in getting my website done, in light of the fact that the next patch may change the way a lot of the planes currently fly.

Sure, I have not tested anything untill the next patch. :rolleyes:
The online compare sounds good, i save this bookmark before, looking forward the clod version :cool:

If this game ever models the BoB spitfires and hurricanes correctly i predict the same thing will happen as happened in Il2- far fewer will fly for blue as they will complain the spitfires are too good at dogfighting, and they will be labelled 'noob' planes!
I'm fine with that- i used to fly a lot on the Skies of Fire server and would frequently have to fly blue to even up the maps. Avoiding any turn-fighting and never engaging a Spitfire unless you had an 'E' advantage were critical.

I'm okay with that as too few people fly these planes the way they were historically- Galland stated in his book 'The First to the Last' that the '... Me109 was superior in the attack and not so suitable for purely defensive purposes as the Spitfire, which although a little slower, was much more maneuverable'. He then went on to make the famous request of Goring to be given a flight of Spitfires.

To be fair.. that sort of stuff is not limited to blue pilots..

Depending on the match up you will find red pilots doing the same thing!

And it is that sort of stuff is why I am making my website..

Because I 'belive' that once people can see a side by side comparsion graph of ingame plane data vs. real world plane data..

And the data matches within say 5%

They will not be able to make such claims anymore!

At which point they will have to look in the mirror and 'realise' the true sorce of thier defeat! ;)

On the flip side

If the ingame plane data does not match within 5% than they will have a valid argument and don't have to look in the mirror! ;)

Hummm may I remind you that Il2 compare does not take into account E ?

The prob with the Spit in old Il2 was not so much with the numbers but with its relaxed "E-liability".

Somehow the very same happen here for now.

@Duk : your comment was funny to read. If I resum you said that It was hated as naturally too good... Sorry but didn't you forgot to mention the fact that only the very best flew the SPit in Il2 ;)

AOA- I appreciate your efforts in collating the data and displaying it for all to see- i've found such efforts invaluable throughout my time playing the Il2 series.

What i really miss is the program Neural Dream created- the 'Aircraft Reference Guide' ( I think it's still on the Mission4Today website). The layout was so easy to use and especially helpful when the aircraft were unfamiliar. As this series expands i hope some talented people produce such excellent work for this.

@Tomcat- in Il2 the Spit is very forgiving. If you make mistakes and find yourself at a disadvantage in a 1:1 engagment you can yank-and-bank your way out of trouble, especially if a 109 is foolish enough to engage in a lengthy rolling scissors type dogfight. I agree the relaxed 'E' liability was suspicious, but the higher wing loading of the 109 may account for that. I found a 109 could outturn a Spit at high speed with a harsh quick turn, but would bleed E very quickly if the hard turn was sustained for more than a few seconds.

What website is this?

Oh neat stuff.

No need!

In that it is something I am well aware of, and none of the standard WWII performance charts like TAS vs Altitude and ROC vs Altitude are depended on the E state. As a mater of fact the test methods are preformed such that E does not factor into the test.

For example, TAS vs. Altitude is a 'level' speed test, as in no change in altitude before or after the TAS value. That is to say you can not dive down from 12kft to 10kft and use that TAS value as the max value at 10kft. The TAS value for 10kft has to be obtained in level flight. That is to say you can not convert altitude into speed (convert energy)

This is a perfect example of a 'theory' that has no real world data to support it..

That is to say, I challenge you to find any real world data on this so called "E-liability" of a Spitfire..

After just a few moments you will realize there is no such data..
Thus no way anyone could compare the in game Spitfire E-Liability numbers to the real Spitfire E-Liability numbers
Thus no way anyone could say how well the in game Spitfire E-Liability is simulated

Which does lead to the interesting question, how do 1C and other company's making flight sims actually model E-Liability numbers?

How do they derive these?

There's no such thing as "E-liability". It is a concept invented by layperson sim pilots, and is not something that is expressly modeled in any serious flight simulator.

When you increase the load factor on an aircraft (i.e. when you pull back on the stick) then you increase the drag coefficient. This is what slows the aircraft down.

But this is the whole point. For me E-Liability is the capacity of a plane to retain energy which is the sum of speed-based energy and altitude-based energy. I do not want to go into detail but basically E-Liability in a turn for instance will depend on the lift a plane can generate by increasing the angle of attack and how much this will cause drag. The more you pull the more lift your plane generates due to higher angle of attack and the tighter you turn. Now basically ALL planes will be able to generate the same amount of lift or let's say the same amount of lift/weight. A plane however that requires more angle of attack to do so will create - by same aerodynamic performance - more drag than one that does not need this. For instance this would happen to a Spit that has a higher weight. In order to achieve same turn radius the heavier Spit would require higher angle of attack and hence more drag would be created slowing down the heavier Spit more.

Again, if the aerodynamic performance is not as well for a plane (at same weight) it would either also have to pull more angle of attack to create the same amount of lift.

Or, even if another not so performing plane can generate same amount of lift with same angle of attack, it still might generate more drag.

Now if we take into account propulsion too, we can basically say that the plane with the better thrust will be more at ease to compensate higher drag, so even if the plane would have to pull stronger for same turn radius (for instance because of higher weight, aerodynamic performance being similar otherwise) it might still be capable to preserve its speed at the same rate as the lighter aircraft if its engine is powerful enough.

So, summa summarum, it is a darn complicated story. My guess is that no flight sim ever gets so deep into detail to really come up with a good set of data. I think all flight sim FMs are based on some parameters and tweeks to fit quantitave and some qualitative criteria for each plane and hoping that for other qualitative criteria the outcome is ok.

Agree. But I feel that for someone who does not understand the basics of flight performance, it is disingenuous at best to explain something to them in terms of the pseudo-property "e liability".

Also agree. There are a lot of 2nd-order differential equations in aerodynamics that are not efficient to solve in real-time, esp. on consumer-level hardware.

Specific Excess Power (Ps) is the measure of cough "E-Liabilty", and takes into account the complete picture, i.e aerodynamics power etc. The Fan plot in Il2 Compare provides a single Ps=0 line at 1000m for all types derived from turn times. From this you can determine each types Sustained G capability which is a function Ps. Fan plots were invented for this purpose.

We also know of the calculated Fan plot that the RAE produced for the 109E3 and Spitfire I at 12,000ft. Comparing the values will provide a comparative measure of Sustained turn performance ... or E under G/AOA. The chart gives the 109E 3 a sustained turn capability of 2.4G and the Spitfire MKI a sustained G of 3G.

A 0.6G sustained turn advantage is pretty significant

Neat On line implementation of Il2 Compare whose responsible for that ? V101_Tom or Ace of Aces ? ... be nice to see the fan plots in there as well.

"Even a child could fly one!" no guesses who made that famous remark!

The simple truth is that many of the pilots who flew these highly advanced machines were just kids fresh out of school with no combat experience.

That remark is testament to Mitchells excellent design - a damned good fighter that a kid and young men could, and bloody well had to, fly against overwhelming odds, excellent Axis fighters and adversaries with more combat experience!

I have to agree with Captain Doggles.. I have never come across that term until today.. So I wouldn't even want to guess at what it means.. I can only assume it is a differnt way of saying specific excess power (Ps).. Which can be calculated from the avaliable IL-2Compare data..

See figure 20 in the following pdf link.

FLIGHT MODEL ANALYSIS OF THE HSFX 5.0b Bf-109G-10 1944

This is the kind of test reports I use to create, until I decided to make a website where people can select the plane they are interested in, at which piont it will calculate all these graphs on the fly (pun intended). I will be adding the Ps chart and others to my website in the following weeks to come

This I..

See the link to the pdf in my previous post.. I have fan plots (aka DogHouse) and Ps charts and more.. I am slowly adding those each weekend that I get some time to work on it.. I actully have the fan plots done, but, I need to add the lables for the constant load factors and constant turn radius lines..

I have done all this before in MATLAB, but never before in a website app in C#, but it is not hard to do, just takes time. My goal is to have everthing that is in that pdf on my webpage.. AND MORE! ;) For example, you can change the fuel loads in my version of IL-2Compare Online, which is something you could not do in the old executable version

Hmmm before someone jumps me on this.. Allow me to say this better than I said here

There that is more correct

Historical performance data for climb typically comes with a climb speed information. This climb speed hardly ever is constant. Often, TAS increases while IAS decreases. This has an effect on climb performance, and it is measurable. Il-2 compare does not take the planes acceleration into account, and the climb performance in Il-2 compare is a little bit higher than what is achievable in game or would be, even if perfectly modelled, with the real plane.

One question asked at the time was "could the average RAF pilot go to war in this". Answer, born out by the many interviews you can still find on Discovery, History, etc channels is "Yes" and "you didn't get into a Spitfire you strapped it on, it was a delight to fly" (Bob Doe I believe). Adolph Galland, comparing it to the Me109: "The Spitfire was ridiculously easy to land".

On the subject of 'E' state, performance, is it right? etc.. A decent flight model will take all that into account. The data for power, weight, drag factors etc have to be correct and the environment data, including gravity, is modelled in.

In simplistic terms 'E' at 500 feet is essentially the same as 'E' at 10,000 feet for the same true speed. E=MC^2. Its when you change altitude, power etc that E changes. Potential E is another matter, you have the potential to develop much more E at 10,000 feet (by diving) than you do at 500 feet, also you have the potential to develop more E by putting up the power.

It seems I need to add some clarification here.

The Term I invented - E-Liability - was part of attempt to make a joke combining the Law of Energy conservation (Em=cte - Em being the mechanical energy of a closed system - ie : every well defined system) and the fact that our beloved Spit in IL2 had the right to bypass it (the dive climb maneuver for example).

SO sorry it was pure un-intentional trolling :oops:

Specific excess power (SPow) is what come close to this - Thx IK.

Just remind that Em = cte is not a true representation of what is really happening. The plane is in fact trading energy with the surrounding air at an huge rate so the the neat amount would be most of the time negative in a dogfight.

For example, flying level if you attempt a climb you'll go higher than if you had started turning just before. An other example is the yoyo move.

A good equation IMHO that give a clear picture of this is the low kinetic energy that stat that the time derivation of the kinetic energy equate the sum of consumed power of a system

dEc/dt = Sum of (P)

With P being the power of the engine, the power consumed by the drag etc... depending only of the speed and the turn rate.


BoT :

Following IK remark : 0.6G is a huge diff.
But doesn't it look right if you compare the wing area ?
However it would be only an advantage in a flat turn. Slow speed turn with vertical added would be problematic for the Spit pilot giving the wing being prone to dyn stall (lower aspect ratio + thiner + elliptical planform) and the ctrl sensitivity in pitch that you alrdy hve demonstrated.

But do we hve similar curves for the Hurri ?

The technical theory FM arguments are way over my head but I appreciate everyones input. I just read Cambers post (excellent too!) and it refers to the Acusim modelling of the Spit.

I asked someone who has this installed how the Spit compared to the one in CloD regards handling? His opinion was that it was very similar (better in some aspects regards performance).

I appreciate that it has little significance in contributing to this discussion but I would be interested to know if there is a marked difference between the FM modelling given to us by MG and another such as Acusim both of whom I would imagine are researching and using the same data.

Typically? Well I have not counted all the test reports that included BCS vs. those that did not include BCS, but based on my memory I have seen more test reports without BCS than with

Same is true wrt altitude in top speed testing.. It is impossible to maintain a 'constant' altitude.. But the NAVY test documents say the altitude must be held within a 'range'.. If I remember correctly it was something like +/-100ft or 150ft. Same goes for BCS.. It is impossible for a human to maintain a constant BCS. The goal of each is to keep both as constant as humanly possible during the test from one second to the next. Some if not most planes ROC performance required the BCS to be adjusted as altitude increased, but the change was done such that the transition was smooth and within that +/- acceptable range such that the IAS could still be considered constant from one second to the next.

Often? Actually TAS 'always' increases with altitude.. But in WWII TAS gauges were the exception to the rule, that is to say most if not all fighters only had IAS gauges. Thus the test pilot focus was on the IAS, but not because he didn't have a TAS gauge as much as the stall speed is realities to IAS, not TAS. Thus they would keep the IAS as 'constant' during the ROC test from one second to the next, While TAS increased during the test due to the increase in altitude.

That is good news wrt ROC testing because as in real life the goal was to keep the BCS as constant as humanly possible. And as any high school physics book will tell you, when velocity is constant acceleration is ZERO. So another way of putting it, you could say that during a ROC test the goal is to keep acceleration as close to ZERO as humanly possible, even during the transitions in BCS

Maybe.. I guess it really depends on ones definition of 'a little bit' but based on the +/-5% acceptance the IL-2Compare data falls well within (matches) the manually flown (3rd party test pilot) test results that I have done.

Fact?

Really? Well than there must be some well defined and documented test of the ingame spit to make such a claim.. Right?

Can you provide us the link?

I think that would be interesting to see just how that test was conducted.

On that note, here is a classical WWII ZOOM test I did back in 2007 on the Spit 25lbs

Spitfire MkIX 25lbs

And I saw nothing in that test that would suggest it was ignoring the laws of physics..

Also, when I did the FM ANALYSIS of the Spitfires, I saw nothing in the Ps charts or Doghouse charts that would suggest it was ignoring the laws of physics

But maybe this test your referring to does?

So I am looking forward to the reading the test that your FACT claim is based on!

Thanks in advance!

Not during zoom climbs.

Neither his point nor mine.

Regarding acceleration in a climb, that's TAS you need to look at, the energy of a plane going 600 in vacuum and going 600 in sea level atmosphere is the same, even if IAS in one case is 0 and in the other 600. That energy needs to be accounted for. Flying the plane a a constant IAS will not give you an acceleration free climb.

As an example, the acceleration during a climb at a constant IAS of 360 km/h to 6000m in standard atmosphere will cost you about 400m in altitude, or 7% in average climb rate. At lower speeds, closer to the typical climbing speeds of WW2 aircraft, the loss is less, around 3-4%.

Well AoA I won't make any comments on the SPit in IL2. It's way out of topic and CoD does not deserve that with all the efforts they hve made to make it credible

But I figure you never attempted to B&Z a spit in Il2. My personal safety minimal margin was 500 meters to regain after each pass to find myself still above the free ballooning alt of the beast ;)

realitive to IAS TAS increases with altitude..

Thus if you 'climb'

TAS will be increasing

I think I found the source of our miscommunication?

I am talking about a ROC test

Where there is no acceleration!

The speed (BCS) is kept as constant as it can be kept (humanly possible) during a WWII style ROC test

I only brought it up because you were saying the IL-2 Spit and the CoD Spit have the same problem..

Or did I misunderstand you when you said the following?

You figured wrong ;)

Which IMHO says more about the relative pilot skills than the FM and thus is not proof that the Spit is ignoring the laws of physics

As an example of WW2 climb tests, look at table I in this Spitfire IX test, you can see a constant IAS up to FTH and a constant TAS above FTH. Il-2 compare will always give you constant TAS, which will give you the somewhat higher climb performance below FTH, about 100 fpm in this case. Less than 5% obviously, and all I wanted to say.

The A2A Spifire is sweet to fly and similar in handling to the CoD although to me it 'feels' nicer. The IIa seemed to me to have better acceleration but I haven't done any comparative tests. The A2A Spit Ia only comes with the fixed 20' pitch wooden prop or the DH5-20 2 position three bladed prop (like the DH5-20 in CoD). It does not come with a CSP. It is more sophisticated that CoD in that the engine is more prone to lasting damage through mishandling, e.g. overheating is not only hard to overcome but with Accusim modelling it causes lasting damage to the engine which stays with you on the next flight unless you put right 'in the hangar'. If looked after properly it is just fine.

I'll try to find time to compare level speeds and climb to height in the two DH5-20 versions.

Cheers Klem! From your observations, apart from CEM/performance, etc, the handling characteristics are at least reasonably similar which is re-assuring.

Whatever talents AcuSim has, Microsoft flight SIm has (traditionally)one of the worst FM in plane simulation. So that's not really a good comparison for CoD.

Got data to back that statement up?

No really, you can't feel it ?:confused: