Suggested, complete Spitfire lineup for Aces High

[MiloMorai]

Originally posted by Crumpp

The Bf-109E DB 601A was capable of 1.42ata, a rating which clearly is the equivelent of (+12) boost for the Merlin.

 

Not sure what you mean but 1.42 is only about 5.5lb of boost.

16lb of boost is near to 1.85-1.90ata. (the graph stops 53"Hg; 52"Hg = ~1.80ata)

[Neil Stirling1]

http://hometown.aol.co.uk/JStirlingBomber/clock+work.jpg

Neil.

[Crumpp]

Not sure what you mean but 1.42 is only about 5.5lb of boost.

Hey Milo,

Both are the emergency power ratings for the aircraft being compared.  I was not comparing actual boost pressure.

Right now we are comparing the 109 at "climb and combat power" vs. the Spitfire at "emergency" power.

In other words, the Spitfire is giving everything it's got while the 109 is shown at a reduced power setting speed.

Neil,

Nice magazine article.  It is a 1940 article speculating about an engine from a enemy power at war.  You can get a good idea of the level of expertise the RAE had in German equipment by examining some of the reports and comparing them with the German operating instructions.  Not a failing of the British intelligence, just a fact of life in wartime.  Think of it this way, would you take your Jaguar to a Chevy dealer for a rebuild?

While testing of foreign aircraft by opposing warring powers is not useless to us in our studies, it is far from the "end all" of the capabilities of that aircraft.

All the best,

Crumpp

[MiloMorai]

OK, just wanted to be sure where you were coming from. It was a bit ambiguous.

What was the time  limit at 12lb?

"The DB 601A data charted above comes from the DB 601 A u. B Moteren-Handbuch of May 1942, which added the 1 minute take-off rating. This take-off rating was not mentioned in the Me 109 E Flugzeughandbuch; in fact the engine limits are stated as 1.3 ata, 2400 rpm."

1.42 was limited to 1 min.

[Karnak]

Originally posted by MiloMorai
What was the time  limit at 12lb?

In one of the links or quotes in this thread it is mentioned to be 5 minutes at +12lbs boost.

[Neil Stirling1]

Hi Crump, Abflugleistung I think means "takeoff achievement". The May 1942 DB 601 A  und B manual  states for the use of 1.4 ata "am boden beim abflug" meaning i think "at the soil with the takeoff" Have you any proof that 1.4 ata was used/cleared for combat? Butch will know.

Neil.

[Squire]

The graph clearly states 6.25 lbs. unless im looking at the wrong one.

Shows @ 2800 fpm climb rate for both a/c.

The Speed graph indicates use of +12 lbs.

[mw]

Hi Guppy35:  "A bit tough to argue with that mw"  

you watch   If the case is sound, however,  one can always resort to smears and personal attacks

Milo, Karnak:  see Dowding's memo with respect to time limit on +12 lbs.



Angus: yeah, there are guys here that are very knowlegable about Spits: Guppy, Karnak,  Kev367th, Milo, nashwan, Squire,  and yourself, etc.  Very impressive.  Fun subject too  Nice thread Karnak!

Good stuff Neil, dang I've never seen that Flight article. I have  heard though that bombers could use 1 minute take-off power.

[Crumpp]

Hi Crump, Abflugleistung I think means "takeoff achievement". The May 1942 DB 601 A und B manual states for the use of 1.4 ata "am boden beim abflug" meaning i think "at the soil with the takeoff" Have you any proof that 1.4 ata was used/cleared for combat? Butch will know.

Neil,

AFAIK the DB605A was never cleared for 1.42ata not the DB601A as used in
the 109E.

You are correct for Abflugleistung, however I am referring to Erhohte Kurzleistung.
The DB power chart is a 1937 curve IIRC.

I have not seen the rating "Take off and Emergency" in the early war period before 1940 as a German standard as it is later in the war.  However the Flugzeug-handbuch for the 109E4 clearly states 1.42ata as the "Emergency Short Achievement" rating under paragraph IVd.  I suspect that ratings for German engines were standardized at some point early in the war.

I am referring to the level speed graph, Squire, and the 109's boost used on that graph.  You must compare emergency power to emergency power.  Not top power to climb.

All the best,

Crumpp

[Squire]

Ahh, I thought you were talking about sustained climb rate. I agree, you have to talk apples to apples, as it were.

If you really want to get into muddy waters, you have several versions of each fighter a/c in the BoB as well. Hurricane I and II, Spitfire I and II, 109E-3, 109E-4 ect. Were there not 109E-7s at the closing stages in some quantity?...

I will say I think there tends to be too much "heated" debate over 5-8 mph or a small climb rate difference sometimes, any of the operational fighters in WW2 that saw hard use (like the BoB) would rarely hit their "test" #s anyways. If you are looking at a significant difference, thats something else. Its still interesting to have a look at it all, and I think we all learn something. I know I do.

"Emergency Short Achievement" - Hey I use that when the boss shows up downstairs! Over use will result in long term fatigue though...

[Neil Stirling1]

HI Crump,

The DB power chart is a 1937 curve IIRC.

And its in the DB 601 A u. B Motoren-Handbuch Stand Mai 1942.

However the Flugzeug-handbuch for the 109E4 clearly states 1.42ata as the "Emergency Short Achievement" rating under paragraph IVd.

From DB 601 A u. B Motoren-Handbuch Stand Mai 1942.

http://hometown.aol.co.uk/JStirlingBomber/DB+limits.jpg


Neil

[MiloMorai]

Originally posted by mw
Hi Guppy35:  "A bit tough to argue with that mw"  

you watch   If the case is sound, however,  one can always resort to smears and personal attacks

 

Mike, I would hope this myth some ppl claim for 100 fuel use and scarcity during BoB can now be put to a peaceful rest,  after this thread.

Now if only these same ppl would accept that 150 fuel was in widespread use in the last year of WW2. Further, it would be nice if these same ppl could provide C3 fuel production/delivery/use numbers for the last year of WW2.

[MiloMorai]

Originally posted by Neil Stirling1

From DB 601 A u. B Motoren-Handbuch Stand Mai 1942.

http://hometown.aol.co.uk/JStirlingBomber/DB+limits.jpg

Neil

Interesting Neil. Both 1.3ata on the DB and 12lb on the Merlin have the same limit  usage restriction (5 min).

[Crumpp]

And its in the DB 601 A u. B Motoren-Handbuch Stand Mai 1942.

Neil,

Since I have just about every Luftwaffe manual on the FW-190A series, it is not unusual for information that is still good to be reprinted in later manuals.  

All the best,

Crumpp

[Neil Stirling1]

Crump what does the E-4 manual say regarding the use of  Emergency Short Achievement? When and how is it to be used?


Neil.