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

[Crumpp]

Unlike your car, dvd player, or your standard military manual.....

Pilot Operating Notes are part of the airworthiness of the aircraft and a legal document. They carry the weight of law by convention.

The is the master document for all flight information, and pilot's may not deviate from the POH unless specific approval has been granted by the relevant aviation authority for such deviation.

Don't confuse the articles discussion of the GAMA changes in 1975 that put all convention signers on the same format. Manufacturers of light civil aircraft tried to save a few dollars during one of the darkest periods in General Aviation by cutting corners on the POH's. The result was the GAMA changes which standardized POH for all convention signers and everyone adopted the same format.

The POH is approved by the aviation authority during type certification, and issued to an aircraft when it is manufactured as part of the initial airworthiness certificate.

http://ezinearticles.com/?Pilots-Ope...101&id=6521261

It has been that way since 1919!!

As for for the "engine parts" conforming during operation, that is normal for all engines. In fact it is called the "break in"!!

No engineer looked at a part on the assembly line that would destroy the engine and said "keep churning em out boys!! We can win the war with our airplanes that won't fly".

That is really stupid. He looked at it and said, "Yes it is bent but it is still within tolerenances and won't effect anything, keep working"

Happens all the time in aviation and does not violate any convention.

[Crumpp]

Crumpp, still some 17 years left of service, going for the full service time Anyways, when looking at that Spitfire Mk.II manual June 1940, paragraph 55 (stating it should be carefully noted) clearly says +12lbs up to 1000ft for take-off or maximum 3min. Rest seems to be +9lbs (all-out for 5min) with no alt restrictions. And continuous/max cruise is +7lbs. So that pretty much says it all IMHO.

The Military is a good career. I did all of my time in Special Operations. Started out in Rangers and then went to Special Forces.

I agree with your interpretation on the Spitfire Mk II Notes.

It is a fact the Spitfire Mk II was using 100 Octane in June 1940 because the Notes On the Merlin engine specify that as the only option. The emotional investment in this issue so high that many participants confuse In use with all operational units.

The Operating Notes are a followed and the proceduresYou cannot say "all operational" Spitfire Mk I's or Hurricanes were using 100 Octane in June of 1940.

The USAAF did the same thing when they converted to 100 Octane (100/130 grade). They published instructions to use 91 Octane for training and OCONUS and 100 Octane for operations. The Pilots Operating Handbooks reflect the fuel changeover after that Technical Order was published.

You don't see the Notes on the Merlin Engine being updated until January 1942.

[Seadog]

Originally Posted by Crumpp

T

The Operating Notes are a followed and the proceduresYou cannot say "all operational" Spitfire Mk I's or Hurricanes were using 100 Octane in June of 1940.

Originally Posted by Seadog

I have repeatedly challenged you to produce evidence of even a single Spitfire/Hurricane 87 octane operational squadron combat sortie during the BofB. This should be an easy task if, as you contend, the majority of RAF FC Spitfire/Hurricane operational squadrons were using 87 Octane fuel.

So I'll issue the challenge again and again, until you answer it or admit that your contention is unsupported by the historical record.

I'm still waiting for a reply.

Again, where's the evidence for combat sorties flown with 87 octane fuel? We have numerous sources that state full conversion to 100 octane and a complete lack of documentary evidence of 87 octane fuel use by Spitfire/Hurricane operational squadrons during the BofB.

[Glider]

Crumpp
This is all very interesting but everyone I am sure is still waiting for you to try to support your belief about 16 squadrons.

All I have seen is a pre war statement of intent to have 16 squadrons of fighters and two of bombers.

Or am I right in thinking that this is now something in the past, like your belief that 1940 was about operational testing and you now simply believe it was less than 100% of fighter command.

[JtD]

I've checked a few manuals and some lag behind in terms of amendments by up to half a year.

[NZtyphoon]

Originally Posted by Crumpp

I agree with your interpretation on the Spitfire Mk II Notes.

It is a fact the Spitfire Mk II was using 100 Octane in June 1940 because the Notes On the Merlin engine specify that as the only option. The emotional investment in this issue so high that many participants confuse In use with all operational units.

The Operating Notes are a followed and the proceduresYou cannot say "all operational" Spitfire Mk I's or Hurricanes were using 100 Octane in June of 1940.

The USAAF did the same thing when they converted to 100 Octane (100/130 grade). They published instructions to use 91 Octane for training and OCONUS and 100 Octane for operations. The Pilots Operating Handbooks reflect the fuel changeover after that Technical Order was published.

You don't see the Notes on the Merlin Engine being updated until January 1942.

The only one who has the "emotional investment" on being right in this thread is Crumpp, who has been ignoring anything which is inconvenient to his case, including placing me on his ignore list. Look at how much his arguments have changed and look at how inconsistent everything he says has become.

The timeline of the Merlin's adaptation for using 100 Octane fuel:

1937 Merlin II developed 1,536 hp at +18 lbs on special blend of fuel;

1938 Figures for Merlin II and III using 100 Octane fuel presented at Paris airshow, albeit no mention of +12 lbs boost; clearly whatever redesign of the cylinder heads was needed Rolls-Royce would have had the job well in hand.

1939 Merlin II & III tested and approved for +12 Lbs boost; September 1940; Blenheim IVs of BC cleared to use 100 Octane fuel in outer wing tanks. November decision that reserves of 100 octane fuel adequate to allow all Merlins to be modified to use the fuel.

1940 February - first squadrons converted to use 100 octane; March A.P1590B/J.2-W specifically states conversions well underway; May - 100 Octane used by Hurricanes and Blenheims based in France during combat ops....etc etc etc.

Again, Crumpp is arguing for the sake of argument because he's always right, no matter what.

I came in here for an argument

[Glider]

Crumpp
You might be interested to know that in December 1938 the Air Ministry were planning to ensure that there were adaquate supplies of 100 Octane should war break out. There were two main factors, The Hartley Committee which recommended the size of the RAF in war and once you know the proposed size of the RAF, you can start estmating the demand for fuel.

The PLans were put forward

Plan F 124 squadrons with 1,736 front Line Aircraft
Plan L (intermediate) 161 squadrons with 2,541 front line aircraft
Plan L (Unltimate) 163 squadrons with 2,549 front line aircraft

It was estimated that it would take two years to get to Plan L which was the reccomendation put forward. so you are talking about the end of 1940.

It was estimated that this would need between 670,000 - 735,000 tons of 100 Octane a year and plans were put in place to deliver this capacity by the end of 1940.

What is interesting is that in Dec 1938 plans were in place for the support of 2,500 front line aircraft with 100 octane by the end of 1940. When you remember that in Aug 1940 all RAF front line commands were authorised to use 100 Octane, you can see that these plans although modified as circumstances unfolded, were basically kept to. The modification was of course, mainly that the war started before anyone expected it to

Its also worth remembering that we have a summary paper from Nov 1940 saying that the UK were well ahead of their plans iro fuel stocks

I should acknowledge that I believe Kurfurst was the first person to post the paper outlining the RAF 1938 plans on a different forum.

[Crumpp]

Glider,

Operating Note instructions are pretty definative. If it does not appear in the Notes on Operating the Merlin Engine, it was not common at the time of Note Publication.

[Glider]

Originally Posted by Crumpp

Glider,

Operating Note instructions are pretty definative. If it does not appear in the Notes on Operating the Merlin Engine, it was not common at the time of Note Publication.

An obvious question I admit, but if these Instructions were so limiting, how do you explain the combat reports and other documentation confirming the use of the fuel in these engines? You have a theory that the engines couldn't be used with the fuel, but we have firm evidence that it was, not a thoretical point which is all you have. There is a clear difference.

I take this chance to remind you of a simple clarification that I am unsure of Crumpp. We are still waiting for you to try to support your belief about 16 squadrons.

All I have seen is a pre war statement of intent to have 16 squadrons of fighters and two of bombers.

Or am I right in thinking that this is now something in the past, like your belief that 1940 was about operational testing and you now simply believe it was less than 100% of fighter command.

I only ask this of you as I do not know what your current view is.

[Crumpp]

An obvious question I admit, but if these Instructions were so limiting, how do you explain the combat reports and other documentation confirming the use of the fuel in these engines?

Glider,

Documentation like that is useful but one can hardly make the conclusion all operational units were using the fuel. You are making a leap of logic that just is not there. If someone presented Combat reports from November 1945, would you make the conclusion the entire Luftwaffe was using the FW-190D9? Of course not, the report would have to be placed in context in order to be understood.

All the combat report tells you is that on that day and time, that single airplane was using the fuel.

The combat reports must be put in a timeline and in context just like the squadron log books.

Once more, period magazine articles the fuel was "in use" is not all operational units and niether is logistical documentation.

For example:

Sorry, but the Hurricanes were using 100 octane by then

Making the conclusion Hurricanes were using 100 Octane in the Battle of France based off some logistical projections for future war is amatuerish and clumsey. It is a paper tiger. That document is a calculation of projected needs written on 7 May 1940. The British Expeditionary Force was on the Beaches of Dunkirk 18 days later.

How much of those calculation and projections for future war do you really think became ground reality in 18 days?