Inaccurate performance data for BOB fighters in COD comparing to RL data

[Al Schlageter]

Lane, it doesn't matter how many squadrons are shown using 12lb boost, 100 octane fuel, the fact is there was only 16 squadrons that did so and that was in testing, there was never enough 100 octane fuel and the Merlin would blow itself to smithereens if more than 4.5lb of boost was used.

[NZtyphoon]

Originally Posted by Al Schlageter

Lane, it doesn't matter how many squadrons are shown using 12lb boost, 100 octane fuel, the fact is there was only 16 squadrons that did so and that was in testing, there was never enough 100 octane fuel and the Merlin would blow itself to smithereens if more than 4.5lb of boost was used.

Hey, I'm confident that Crumpp will trumpp everyone with extensive documentation, proving beyond doubt that the RAF kept all of its 100 Octane fuel in strategic reserve while only allowing 16 squadrons to use maybe 74,000 tons to cover intensive operational trials - in which only some squadrons would use the fuel full time - in order to convince the RAF that the fuel worked in Merlin engines rated for 400hp. Its gonna happen. Have faith.

[Al Schlageter]

So much for the 1/3 power.

http://forum.1cpublishing.eu/showthread.php?t=18865

[irR4tiOn4L]

Can somebody give me some cliff notes on this and what's wrong with which planes atm? I hear a lot of tips for the 109 vs spit suggesting the 109 dive away/use superior speed. So was the 109 faster, if the spit was supposed to have 12lb boost and 100 octane fuel? How should the 109 fight the spit if the spit was in fact faster, climbed better and outturned it?

Was the G50 really as bad as it is ingame? How is it that it has a higher HP:KG ratio by some margin than the Hurricane yet the latter is practically the equal of the Spit/109 ingame?

All around confused here.

[Crumpp]

Spitfire Mk I Pilots Operating Notes, dated June 1940:



This is an Inspection and Test Certificate for a specific aircraft with a Merlin Mk III engine. Inspection and Test Certificate is probably the same as an FAA Form 337 allowing major modification for research or testing purposes. Note the document clears a single aircraft by serial number on 28 February 1940. The July of 1940 Spitfire Mk II manual clears the Merlin III engine for use of 100 Octane fuel and notes +12lbs may be used.

That is not the Spitfire Mk I but rather the Spitfire Mk II. There is nothing authorizing the Spitfire Mk I to use +12lbs in any of the Operating Notes.

[41Sqn_Banks]

Originally Posted by Crumpp

The July of 1940 Spitfire Mk II manual clears the Merlin III engine for use of 100 Octane fuel and notes +12lbs may be used.

I think there is a typo in this sentence. Not sure if you mean Spitfire I or Merlin XII.

[Glider]

Crumpp Interesting find, can I ask if you can show the page where it mentins the fuel to be used?
If it doesn't then it would be refering to the early war 87 octane as that was the only fuel available. The date of the Pilots Notes is not a definitive statement as was proved by Kurfursts version of the Mk II pilots notes which had an incorrect date.
Other clues would be the instructions re the prop normally around the mid 20's section and the fitting of armour plate for pilots protection normally around item 40.

Look forward to seeing the above.

PS How are you getting on re the proving of 16 squadrons?

[NZtyphoon]

Originally Posted by Crumpp

Spitfire Mk I Pilots Operating Notes, dated June 1940:



This is an Inspection and Test Certificate for a specific aircraft with a Merlin Mk III engine. Inspection and Test Certificate is probably the same as an FAA Form 337 allowing major modification for research or testing purposes. Note the document clears a single aircraft by serial number on 28 February 1940. The July of 1940 Spitfire Mk II manual clears the Merlin III engine for use of 100 Octane fuel and notes +12lbs may be used.

That is not the Spitfire Mk I but rather the Spitfire Mk II. There is nothing authorizing the Spitfire Mk I to use +12lbs in any of the Operating Notes.

And? All that it means is that the Pilot's notes, which you say were printed in June 1940, did not show 100 Octane fuel.

The problem is that any changes to the notes, before the next issue was printed, were altered through sets of amendments which were noted in the inner front cover of the book, and by gummed slips which amended the text in the appropriate locations. All this shows is that this particular set of notes was not amended. Look in the front cover of the notes and you will see this.

Better still how about showing all of us the front covers, including the inner fly leaf and index pages which show the date these notes were printed?

Attachment 3 shows that Merlins in Hurricanes of 151 Sqn had been converted to 100 Octane in February 1940.

The certificate, printed in February 1940, specifically discusses one aircraft, for sure, however, there are TWO problems:

1) There were no Mk II Spitfires in production in February 1940, and the engine is described as a Merlin III, although the power ratings suggest a Merlin XII which, as attach 1 shows, had been cleared to use +12.5 lbs boost.

2)Clearly this was a Spitfire I being used to either type test a Merlin XII or test a Merlin III at higher boost pressures. All it proves is that this particular certificate belonged to a test aircraft. How does this prove that this aircraft was the only Spitfire using 100 Octane fuel, and how did this lone Spitfire manage to chew through 52,000 tons of the stuff?

You have not explained why it is that there is a great deal of evidence showing that Merlin IIIs were modified and rated to use +12lbs boost and there are combat reports showing this. And why did Dowding feel compelled on 1 August 1940 to issue a general notice to all squadrons warning them against excessive use of +12 boost when only 16 Squadrons were using the fuel? http://www.spitfireperformance.com/dowding.pdf