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

[NZtyphoon]

Originally Posted by Crumpp

Who said anything about overhauling the aircraft?

You did, right here:

Originally Posted by Crumpp

A technical order for conversion of the aircraft had not even been published at that time. It is highly unlikely that the RAF was in the process of widespread conversion to 100 Octane without disseminating the technical knowledge to convert the airplanes in the force.

Originally Posted by Crumpp

There is no misrepresentation and the language is quite similar to Service Bulletins and Airworthiness Directives in use today.

It clearly states the two methods of compliance by part number with the technical order and specifies which one will be incorporated in future production engines. The 900(+) Single Engined fighters using the Merlin already in service will have to be converted along with the maintenance stock of Merlin engines.

It means they have to manufacture quite a few new cylinder heads and rings. That is why the conversion will take place during the cyclic service inspection.

You have no idea what technical service documents were published between November 1939 and February 1940, so claiming that none had been published is completely wrong.

The designation AP1590B J.2-W indicates that there were documents before this one

Read AP1590B J.2-W properly Crumpp - it refers to older production Merlins

Paragraph 4 states[B]

1) .Mod.No.Merlin/77 is already being done as service maintenance "is already being done" means that the parts and the information needed was available before March 1940.

2)"Newer engines will already have Mod.No.Merlin/136 embodied" "Will already" means that production engines built before March 1940 incorporated the modifications.

Originally Posted by Crumpp

7. In October of 1940, the United Kingdom as just half the Strategic Reserve required of 800,000 tons. In other words, there is a shortage of 100 Octane fuel in the United Kingdom.

Once again utter nonsense. You are still obsessed with a pre-war document to decide what happened in wartime when a country was under attack. Reserves of 100 Octane never reached 800,000 tons - in 1941, when all services had converted to the fuel, reserves reached a peak of 527,000 tons in February before steadily declining.

Originally Posted by Crumpp

Not at the required consumption to stock ratios....

Strategic reserves of "Other Grades", including 87 Octane fuel, got far lower than 100 Octane in August 1940; 230,000 tons cf 404,000 tons of 100 Octane. Your "required consumption to stock ratio..." is completely erroneous

August 1940

Consumption of "Other Grades" = 26,000 tons plus reserves of 230,000 tons = 256,000 tons of other grades. Heavy bombers, flying boats etc were still consuming 87 Octane fuel considering that big aircraft with big fuel tanks were using the fuel the difference in consumption is a little easier to understand.

Consumption of 100 Octane
10,000 tons plus 404,000 tons in reserves = 414,000 tons of 100 Octane

Get it clear in your mind Crumpp - only 15,000 tons of fuel was needed to cover all operational defensive sorties flown by Merlin powered aircraft of Fighter Command right through the battle. You have never explained what happened to the remaining 36,000 tons of 100 Octane fuel consumed, and you never will. Instead, as per usual, you continue to evade some very basic questions.

[41Sqn_Banks]

Originally Posted by NZtyphoon

You have no idea what technical service documents were published between November 1939 and February 1940, so claiming that none had been published is completely wrong.

Exactly. For example Operational Notes for Pilots on Merlin II and III. 2nd Edition January 1939. It doesn't mention +12 boost, it mentions that a unspecific higher boost than +6 1/4 can be used for take-off by operating the boost-control cut-out.
It doesn't mention any modification, only that 100 octane fuel must be used. (Note that the 4th Edition from April 1940 mentions that "sparking plugs approved to withstand this high boost must be used", so if there was any modification required in January 1939 it would have been mentioned.)
It does however state that this higher boost setting has to be determined on the ground before it is used by listening if there is detonation.

The 4th Edition from April 1940 now gives +12 boost and as already said mentions that specific sparking plugs must be used and that the boost-control cut-out has to be modified to limit boost to +12 boost.
Looks like in April the cylinder head modification was no longer required (maybe because all engines had been modified).

[lane]

Originally Posted by 41Sqn_Banks

Exactly. For example Operational Notes for Pilots on Merlin II and III. 2nd Edition January 1939. It doesn't mention +12 boost, it mentions that a unspecific higher boost than +6 1/4 can be used for take-off by operating the boost-control cut-out.
It doesn't mention any modification, only that 100 octane fuel must be used. (Note that the 4th Edition from April 1940 mentions that "sparking plugs approved to withstand this high boost must be used", so if there was any modification required in January 1939 it would have been mentioned.)
It does however state that this higher boost setting has to be determined on the ground before it is used by listening if there is detonation.

The 4th Edition from April 1940 now gives +12 boost and as already said mentions that specific sparking plugs must be used and that the boost-control cut-out has to be modified to limit boost to +12 boost.
Looks like in April the cylinder head modification was no longer required (maybe because all engines had been modified).

My copy confirms your statement:

Emergency +12 lbs./sq. in. Boost Operation: Pilot's Notes, Merlin II, III and IV, 4th Edition, April 1940, page 6.