109's kill ratio (all variants from B to K)

[GScholz]

Widewing, please check your numbers. At 90 lbs/hr the P-51D can fly for 17.5 hours on internal fuel only, and giving it a very conservative 200 mph could traverse 3508 miles. That's almost intercontinental range. Check your numbers.

[VO101_Isegrim]

Originally posted by GScholz
See §4.5 of what?

Oh, sorry. I though you already know that site. Go see fourthfightergroup.com, an URL is already posted there. There`s a Spit MkIX test there at +25 lbs, and it stated 150 gal/hour for +18 lbs, and 197 gal/hour for +25 lbs.

[Nashwan]

So 150 octane was not commonly used by all until late 44 early 45?

It was used used by most British based fighter squadrons from summer 44, and the British fighter squadrons on the continent switched over in Jan 45.

On ubi forums, I catched him doing that. On one occasion, he vehemently denied that he ever posted these infamous +25klbs Spit XIV tests, or claimed that +25lbs was standard for the plane.

About 2 weeks later, when his actual needs required to boost Spit performance, he suddenly said the very opposite, as can be seen below. He writes there as "Hop2002".

Now if that's what Isegrim had posted over at the Ubi boards, I wouldn't have a problem with it.

Between those two posts, I saw new information, and changed my mind. Isegrim wasn't satisfied with accusing me of changing my mind, and took parts of my June post, and put a date after my July posts on them.

In essence, I said in June I didn't believe that was the normal speed for a Spitfire, and that I had never claimed it was.

By July 15th, I had changed my mind, and said I did believe it was a proper speed for a Spit. Isegrim then took the line "Firstly, I've never claimed that test shows normal Spit figures."
 from June, and posted it with a date claiming I had said it on July 16th, 1 day after I had said the opposite.


I know very well not to trust Isegrim's "quotes", because if he can make up quotes from me, what's to stop him making up quotes from others?

Some nasty tales there Naswan. Not good at all.

You could try reading some of his contributions on the Ubi boards, I won't go into more details, but it's a jibe he's levelled at me, and at least one other.

[Widewing]

Originally posted by GScholz
Widewing, please check your numbers. At 90 lbs/hr the P-51D can fly for 17.5 hours on internal fuel only, and giving it a very conservative 200 mph could traverse 3508 miles. That's almost intercontinental range. Check your numbers.

Yeah, I fixed the typo... had pounds on the brain.. LOL

I was looking at the Flight Operation Instruction Charts for the P-51 and P-38 and became delirious..... It's a common malady at my age.  

My regards,

Widewing

[GScholz]

LOL Widewing, I know the feeling. It's half past three in the morning here now and I'm seeing stars. One last post before I go off in a coma:

"Even the P-38L, with two engines at military power (3,000 rpm, 56 in/Hg) burns only 334 gallons/hour."

That would mean that a single Merlin consumes 167 gallons at mil power. It would seem that Isegrim's claim of 197 gallons/hr for the Merlin at 25lbs boost doesn't sound so far fetched after all?

Edit: Which would mean that the P-51 would consume 1/3 of its fuel in 5 minutes at 9000lbs.

[GScholz]

Originally posted by VO101_Isegrim
Oh, sorry. I though you already know that site. Go see fourthfightergroup.com, an URL is already posted there. There`s a Spit MkIX test there at +25 lbs, and it stated 150 gal/hour for +18 lbs, and 197 gal/hour for +25 lbs.

cc Isegrim, and I think Widewing just proved your point.

[F4UDOA]

Gsholz,

You need your head examined really.

If you ask me how the P-51D would make it back one more time I'll staple the flight chart to your head. This is how. Write it down.

1. My 400MPH at 80GPH cruise for three hours is an example of high speed cruise from the P-51D pilots manual. Just an example, it can cruise at 40GPH or less at 200MPH plus for much longer.

2. Did the fact that the Mustang used drop tanks on the outbound trip ever occur to you?? If the pilot wanted to he could have full tanks hen he arrived over Berlin. That is the reason Mustangs had time to strafe everything that moved and stop for coffee.

And just so you can understand.

10,175LBS with 269 gallons of fuel.

269Gallons = 1614LBS

10,175lbs - 1,175LBS = 9,000lbs leaving 73 Gallons of fuel (439lbs) 3/4 the 109's full tank and enough to fly back.

And BTW the Mustang carried 1880 rounds of .50cal ammo weight 564lbs. How much ammo did the 109 carry?

Here is a point to kick around. Do you think a 109 ever saw a Mustang in combat weighting more than 9500LBS? Doubtfull.

Drag,

I don't think I have ever heard anyone ever say that drag didn't matter until high speed. Are you dreaming? It has more to do with low speed when you are talking about cruising range. Cdi is induced drag or lift drag which is highest at low to moderate speeds.

The 109 had more total drag than the Mustang. How do I know this? Because with 200HP more than Mustang they are the same top speed. That includes Parasite drag, induced drag, cooling drag despite the larger flat plate area of the Mustang.

The fact is the Mustang could cruise for long distances at low power settings because of low Cdi. It didn't carry the most fuel and it wasn't even the most fuel efficient. But it was the lowest drag A/C of it's day. And it was the 109 which lost the BOB while it was the Mustang, P-38 and P-47 that squashed the 190 and 109 over it's home court. You say numbers did it? Well there were 30,000 109's which is the total of the production of the P-47 and P-51 not including the 190's.

The FACT is that the 109 was ***** slapped into history in a big way.

Get over it.

[GRUNHERZ]

Bf109 looks meaner and has a cooler paintjob - does anything else matter?

[dtango]

Isegrim:

...the K-4`s Cd0 as 0.0185 to 0.0190, for a flat plate area of 0.294 m2. The G-6`s Cd0 was 0.023.

As I recal the P-51`s Cd0 was something like .0173 or so, and varied quite a bit with surface finish quality. As since these coefficients are related to wing area, this would give the P-51 slightly more drag than the K-4.

Cd0 = parasite/form drag or the non-lift portion of the total drag polar.  This includes the entire airframe, not just the wing.

Just to clarify, .0173 is less drag then .0185 .  Smaller coefficients = less draggy airframe.  This gives us a measure of how clean the airframe is.  What gets confusing is that coefficients of drag are just that and not the actual drag itself since D = cd * q * wing area.  So the P-51D has a cleaner design than the 109K-4, but the actual parasite drag might be greater because of the greater wing area of the P-51D.

Flat plate area is a comparative figure used to convert dimensionless drag coefficients into something with dimensions for comparison purposes.  It doesn't mean the physical frontal profile of an aircraft.

Equiv Flat Plate Areas:
P-51D - 4.10 sq ft
109K-4 - 3.16 sq ft


Gscholz:

Nah, we don't need a P-51D on 150 octane for a perk ride.  Just put in the P-51H as a perk plane instead!  There would a lot gnashing of teeth if that ever happened!  I can hear the screaming now hehe.  As an avid Mustang fan I would love it but alas stuff like the Ki-84 would and should come before the P-51H in my opinion in AH.

Tango, XO
412th FS Braunco Mustangs

[dtango]

Oh, and one more thing-

Isegrim wrote...

Why don`t you take HoHun`s advice, and confront your opinion with the hard facts : the K-4 was faster, turned and climbed better than the P-51

Faster and better climbing, I'd agree based on the data we've thrown around here.

Better turning, that one is up for debate.  Simply looking at the wingloading based on 7400 lbs and 9500 lbs we get:

109K-4: 42.5 lbs/sq ft
P-51D: 40.7 lbs/sq ft

That suggests to me better instantaneous turn performance for the P-51D.  Add the P-51's combat flaps to that equation improving the Mustang's performance as well.    This also suggests to me that the K-4 would also pay a penalty in induced drag as well.  What I'm not sure about is if the K-4's T/W ratio advantage would offset the penalty in energy bleed and translate into comparable or better sustained turn performance vs. the P-51D.

I would still love to see any charts folks have regarding 150 octane fuel peformance for the P-51D or the V1650-7 engine.

Tango, XO
412th FS Braunco Mustangs

[Neil Stirling1]

Isegrim's K performance figures have been discussed before,

http://hometown.aol.co.uk/JStirlingBomber/109K.jpg

http://hometown.aol.co.uk/JStirlingBomber/109k1.jpg

http://hometown.aol.co.uk/JStirlingBomber/109K2.jpg


As you can see the words "calculated and based"

Something else of interest


http://hometown.aol.co.uk/JStirlingBomber/109g.jpg


Neil.

[MiloMorai]

Originally posted by Neil Stirling1
Isegrim's K performance figures have been discussed before,

http://hometown.aol.co.uk/JStirlingBomber/109K.jpg

http://hometown.aol.co.uk/JStirlingBomber/109k1.jpg

http://hometown.aol.co.uk/JStirlingBomber/109K2.jpg


As you can see the words "calculated and based"

Something else of interest


http://hometown.aol.co.uk/JStirlingBomber/109g.jpg


Neil.

LOL, Neil. Thanks for the saved text.


If one does not believe what Herr Goebbels has to say, why would you then believe what Isegrim has to say ? As can be seen in Neils post, Isegrim can't be trusted with the truth.

[Nashwan]

Thanks Neil.

Butch was adamant that 1.8 ata wasn't authorised until Feb45, 1.98 ata until March 45.

Cut the long story short, he is lying.

Note what Butch says, it's on the second of Neil's links:

"Isegrim you are very wrong on this point, it took a lot of time to clear 1.98ata for operational use.

Indeed operational test began in Feb 1945 with just one Gruppe, and it seems it was cleared for use by all gruppe in March 45."

and futher:

"Yes Chris but I have thanks to george a report from the RLM regarding the operational evaluations made at 1.8, 1.9 and 1.98ata. It seems that 1.8 was not validated until late January 1945, and 1.98 ata test began at that moment. IIRC correctly there were again some sparkplug troubles."

I was posting from memory, and said 1.8 in Feb, 1.98 in March. Butch actually said 1.8 in "late Jan", 1.98 in March. Isegrim, who admits to having the page saved, calls me a liar.

[VO101_Isegrim]

Originally posted by Neil Stirling1
Isegrim's K performance figures have been discussed before,


As you can see the words "calculated and based"

Neil.

Actually I can see te words "it appears to be calculated data for some parts based on some real tests"

To me, that reads something quite different than Neil`s version that it`s ONLY calculated data.

Of course on the same basis we can safely ignore all Boscombe Down tests, since their numbers are nothing else than calculated and corrected values, some parts being based on real tests.

I also find interesting your attitude, Neil. It seems to me that I asked you on that thread about wheter +25 lbs was used operational on MkXIVs, as Nashwan likes to tell us. You answered it was not, perhaps it was used on a handful of individual machines.

I find it worthy to note that you did not show the same zeal about correcting Nashwan statements like the job you did to dismiss the real life performance of the K-4, neither on this thread, nor in any other, like it wouldn`t be againts your liking so that people would believe surrealistic performance numbers when it comes to British planes, and as it would annoy you if people get information about the performance of German planes under operational conditions.


A point of interest is also what schwarze man said :

"Hi Butch! If you remember I gave you a copy of the third (!) edition of the DB/DC Hanbuch dated 1 Dec 44 , listing the 1.8/1.98 RATINGS."

It`s quite clear.

So as it stand now, we have the Handbuch (manual) itself, which says 1.98 ata is possible some time ago by 1 Dec 44, while Butch assumes (see his wording.. "it seems" etc.) it is not, because he has some operational evaluations which tested boost rates, but doesn`t explicitely say they were not cleared by that time.

I take the facts displayed in the Handbuch over anyone`s, even Butch`s assumptions.

Otherwise, thanks for the engine listing document, Neil. It seems that according to it, the boost was raised to even 2.1 ata on the DB 605 D.

But of course we can come to an agreement in this, and using the same logic, we can safely assume that the Griffon 65 was not cleared for +21 lbs until July 1945, since the first known operational evaluation is listed for it at that date for a Mk 21. Silly logic, but let`s apply it both ways.

[VO101_Isegrim]

Originally posted by dtango
Oh, and one more thing-

Isegrim wrote...


Faster and better climbing, I'd agree based on the data we've thrown around here.

Better turning, that one is up for debate.  Simply looking at the wingloading based on 7400 lbs and 9500 lbs we get:

109K-4: 42.5 lbs/sq ft
P-51D: 40.7 lbs/sq ft

That suggests to me better instantaneous turn performance for the P-51D.  Add the P-51's combat flaps to that equation improving the Mustang's performance as well.    This also suggests to me that the K-4 would also pay a penalty in induced drag as well.  What I'm not sure about is if the K-4's T/W ratio advantage would offset the penalty in energy bleed and translate into comparable or better sustained turn performance vs. the P-51D.

Tango, XO
412th FS Braunco Mustangs

Yes, you are right that the P-51D has lower wingloading than the K-4, however it doesn`t tell it all. Lower wingloading does not automatically equals better turn rate, it is more a factor of actual liftloading. Depending on the wing`s design, it may develop more or less lift. As it stands, the P-51D had laminar flow wings, which lowered the drag, but this came at the cost of lower lift, especially under high G loads.

The 109s had a conventional wing, and were equipped with automatic leading edge slats. These opened out at low speed or at high speed under high G loads, and restored to airflow (=lift) which would have been long separated otherwise due to turbulance. That`s why it become so common on modern jets.

As can be seen below :



This seems to be supported by the AFDU`s test, where they pitted the higher wingloading FW 190A vs. P-51B, yet they found their turning performance basically identical. I`d like to add that 109s were generally found to be the better turning machines in all German and Soviet tests vs. 190s. Also, stall characteristics of the 109 were very gentle and forgiving with plenty of warning, as opposed to the P-51. This also helped the pilots to push their aircraft to the limits of stall.

The parts I see the P-51 had advantage is basically roll rate over 300-350 mph IAS, and advantage in longer dives.  Arguably, six .50 are easier to use vs. fighters, too. It has similiar top speed and a high cruise speed, which makes it equal to the K in that regard.
IMHO, the K has advantages on the following areas : speed (slight adv.), accelearation, handling and climb, roll rate below 250 mph (large advantage), turn rate (moderate advantage).