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FM/DM threads Everything about FM/DM in CoD

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  #1  
Old 06-04-2012, 05:26 PM
JtD JtD is offline
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Quote:
Originally Posted by Crumpp View Post
All aircraft fuel must be specified.
Not referenced in aircraft and engine manuals, though. Because there was a variety of 100 octane fuels which could be used. Asking for THE specification of "100 octane" is like asking for THE flavour of "ice cream". There are plenty.
  #2  
Old 06-04-2012, 05:40 PM
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Crumpp Crumpp is offline
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Quote:
Asking for THE specification of "100 octane" is like asking for THE flavour of "ice cream".
No it is not.

From the January 20, 1943 Edition of the P-47B, C, and D Pilot's Flight Operating Instructions:



All fuel is specified by convention and by convention is part of the airworthiness instructions for the design. The aircraft's publications will list the fuel by specification that is authorized.
  #3  
Old 06-04-2012, 06:11 PM
JtD JtD is offline
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Originally Posted by Crumpp View Post
No it is not.
Congrats, you just found one. I guess if you look a little bit more, you can find a dozen others, at least half of which could be used with the Merlin.
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Old 06-04-2012, 06:48 PM
Glider Glider is offline
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I do like the way that the big questions get ignored while attention is diverted down side streets.

The arguement seems to be the RAF couldn't use 100 octane because a manual that may or may not have an accurate date, may or may not have all the updates posted in it, didn't mention 100 Octane in one section. Maybe its being simplistic but if I have a combat report from a Spitfire Unit saying that it was used in combat then the engine had been modified to use it and it was used.

However there is no doubting that on average 10,000 tons of the stuff was consumed each month from April - July 1940. We have combat reports that say that it was used and station reports that say that they had been equipped with 100 octane. We also know that Bomber Command, Transport Command, Coastal Command, Non Operational units didn't use it until post August 1940
So if the nay sayers say that FC didn't use it, who did?

Its worth remembering that the whole of the UK only used 36,000 tons of fuel a month so 10,000 tons is just under 30% of the fuel used in the UK. Now if Crumpp can give a reply to that question with some evidence instead of just another theory then its worth paying attention to it.

Last edited by Glider; 06-04-2012 at 06:52 PM.
  #5  
Old 06-04-2012, 07:08 PM
JtD JtD is offline
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Blenheim IV manual amendment 3 issued no later than January 1940 says 100 octane in the outer fuel tanks. I'd therefore disagree that BC did not use 100 octane until August 1940.
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Old 06-04-2012, 09:14 PM
Kurfürst Kurfürst is offline
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Originally Posted by JtD View Post
Blenheim IV manual amendment 3 issued no later than January 1940 says 100 octane in the outer fuel tanks. I'd therefore disagree that BC did not use 100 octane until August 1940.
Agree. In addition the papers David showed specifically mention that ca. 3-4 Bomber Command stations were only to be supplied with 100 octane fuel.

So I guess the million dollar question is who (BC Stations, FC Stations, manufacturers etc.) used and what amount of the fuel, and in what role (operational/non-operational flights, test trials).
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  #7  
Old 06-04-2012, 09:59 PM
Seadog Seadog is offline
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Quote:
Originally Posted by Kurfürst View Post
Agree. In addition the papers David showed specifically mention that ca. 3-4 Bomber Command stations were only to be supplied with 100 octane fuel.

So I guess the million dollar question is who (BC Stations, FC Stations, manufacturers etc.) used and what amount of the fuel, and in what role (operational/non-operational flights, test trials).
Show us evidence for at least one operational 87 octane RAF FC combat sortie during the BofB or admit that you have no evidence to contradict the multiple sources that state 100% 100 octane use by RAF FC during the BofB, such as:


Quote:
...I do not believe that it is generally recognised how much this
superiority would have been affected had not the decision been
taken to base aircraft engine design on the use of 100-octane
fuel instead of the pre-war standard grade of 87-octane rating.
In fact, it was only a few months before the Battle of Britain
that all fighters were changed over from 87- to 100-octane
fuel, a change which enabled the Rolls-Royce Merlin engine
of that period to be operated at an increased supercharger
pressure which immediately gave an extra 200 h.p. or more.

Subsequent engine developments made possible by the use of
100-octane instead of 87-octane fuel have since permitted a
truly phenomenal increase in the power of the original engine
without any change in its basic size or capacity.
It is very interesting to refer back to the records of serious
discussions which took place only a year or two before the war
when certain authorities expressed the very gravest misgivings
at the proposal to design engines to require a '' theoretical type
of fuel" (i.e., 100 octane), which they feared would not be
available in adequate quantity in time of war, since we were
mainly dependent on America for its supply. Fortunately for
Britain, the majority of those directly concerned took a different
view, and I might quote a rather prophetic statement made by
an Air Ministry official at a Royal Aeronautical Society meeting
in February, 1937, who, in referring to the advent of
100 octane, said: " Let there be no doubt, however, that
petroleum technologists and fuel research workers now have
the opportunity to provide by their efforts an advance in aircraft
engine development, with its effect on air power, which
the engine designer by himself cannot hope to offer by any
other means."
May I conclude by also quoting a reply reported to have
been made recently in the U.S.A. by Mr. Geoffrey Lloyd, M.P.,
Joint Parliamentary Secretary to the Ministry of Fuel and
Power, in answer to the question: " Do you think 100 octane
was the deciding factor in the Battle of Britain in 1940 ? "
To which Mr. Lloyd replied: " I think we would not have won
the Battle of Britain without 100 octane—but we DID have
the 100 octane."

Nevertheless, let us not forget that between the fuel and the
airscrew there are also many other links in the chain, any one
of which, had it failed, could have vitally affected the issue,
while all the technical superiority in the world would, of course,
have been of no avail at all without the efficient training, skill,
and courage in combat of the Battle of Britain pilots.


Flight Magazine, Jan 06 1944
http://www.flightglobal.com/pdfarchi...0-%200044.html
  #8  
Old 06-04-2012, 11:42 PM
Glider Glider is offline
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Quote:
Originally Posted by Kurfürst View Post
Agree. In addition the papers David showed specifically mention that ca. 3-4 Bomber Command stations were only to be supplied with 100 octane fuel.

So I guess the million dollar question is who (BC Stations, FC Stations, manufacturers etc.) used and what amount of the fuel, and in what role (operational/non-operational flights, test trials).
Why do you always ignore the other papers that show the rule of thumb was to have 5/6th of the fuel to be 100 octane and 1/6th 87 octane. You know that only 4 No 2 Grp stations were 100% equipped with 100 Octane.
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