P51 service ceiling

[MiloMorai]

The reason is very simple, the combat range had been exceeded for the Spits, by the allied bombers, hence, other than shipping patrols and training flights, not much use for the spits, from late 43 till end of war. NOt sure, but only could find a intercept mission against JU-88's attempting to bomb shipping in the Northern end of the Channel between Ireland and Holland, by Spit 16's.

Never heard of the 2 TAF then, have you. Spit 9s (RCAF 401) were one of the first Allied a/c to shoot down a Me262

[GScholz]

[ad hominem removed]

Even Boyington's boys fought above 30,000 feet in the Solomons and I know they weren't fighting Germans!

I would really like to see some documentation on that claim. Sure, American pilots would cruise at high altitude to gain the initial advantage, and increase their range. However, to my knowledge no Japanese plane is able to fight at 30k; the few that can even get up there would be so close to their service ceiling that they'd struggle to stay in level flight. Boyington would have had to come down to fight them.

[GScholz]

Check the action reports and you find that more than a few battles were fought over 30,000 feet regardless of whether spitfire, P47, or P51.......with the enemy being equally high.

Type 30,000 in your "find" dialog on this document linked below for spitfires.

Better yet, try numbers like 37,000.

http://www.spitfireperformance.com/spit9v109g.html#combat-reports

I find the same for p51 and p47.

These are all from 1942 and 1943. In other words before the Allied landings in Normandy. You don't fly close support missions if you don't have an army to support. We are talking post D-Day here...

[GScholz]

The reason is very simple, the combat range had been exceeded for the Spits, by the allied bombers, hence, other than shipping patrols and training flights, not much use for the spits, from late 43 till end of war. NOt sure, but only could find a intercept mission against JU-88's attempting to bomb shipping in the Northern end of the Channel between Ireland and Holland, by Spit 16's.

This is just wrong. RAF fighter units would operate out of captured Luftwaffe airfields in France, the Low Countries, even in Germany itself. To my knowledge the first Spitfire over Berlin was a Spitfire PR XI, flying from Allied controlled territory in France on 26th June 1944. It took this picture of Tempelhof airbase.
 

[GScholz]

Ok... I've gone through Tony Wood's document "Reich, West & Südfront August-December 1944".

Kill claims are not really a reliable measure; success does not equal effort. It would have been better to use sortie rate, but we use what we have...

First I removed the "Südfront" listings, leaving only Reich (strategic) and West (tactical). I further separated Reich and West into two separate documents...

https://dl.dropbox.com/u/26232318/Luftflotte%203%20-%20LwKdo%20West.doc

https://dl.dropbox.com/u/26232318/Luftflotte%20Reich.doc

...so that Word could automagically count kills (lines).

I found that Luftflotte Reich, including night-fighters, accounted for 1,537 of the documented claims. Luftflotte 3 / Lw.Kdo. West accounted for 1,033 of the documented claims. Reich+night-fighters thus make up 59.8% of the documented claims, leaving 40.2% to the tactical units.

Now... Oldman claimed that the tactical component of this chart...



...just "simply indicates the German organization table", or in other words they were tactical only on paper and were really used in strategic defense. He continues: " 'Western Front Tactical Force' units, such as JG26, were frequently committed to high-altitude interception missions."

The numbers show this to be in error. I took a tap-counter and went through the West (tactical) document and counted the kill claims that were listed at altitudes above 5,000 meters; the result was 46.

46!

Out of 1033 documented claims only 46 were higher than 5,000 meters. Frankly I found that astounding.

Out of curiosity I then counted the claims that were listed at under 1,000 meters. The result was 188 + 11 that were listed as "tiefflug", meaning low-flight between 10 to 600 meters.

So we have:

46 claims above 5,000 meters
199 claims below 1,000 meters
788 claims somewhere in between.

Next I wondered what sort of aircraft did these" tactical" units shoot down? I found that the vast majority are fighters/fighter-bombers, with most of the rest being medium-bombers and support aircraft (a lot of C-47s were claimed over Arnhem).

I tap-counted the number of B-17 and B-24 claims by the West (tactical) units. The number is 35.

I also looked specifically at Lancaster claims, and their altitudes ranged from below 2,000 up to 5,000 meters with most at around 3,000 meters. A single Lanc kill was recorded at 5,500-6,000 meters.


Note: About 10% of the claims have no altitude listed. In addition I consider my counting to have a margin of error of 5%. Total margin of error would then be about 15%.


Conclusion:

No.  Just....no.  With the barely-arguable exception of the period June-August, 1944, and again in January, 1945, Luftwaffe activity on the Western front after the invasion was virtually entirely directed to opposing the Eighth Air Force.  Even the forward-based Gruppen - and there were only a handful of those after August 1944 - were often directed to 8th AF interception.

This is incorrect. The balance of claims indicate that there was an about 50-50 split in Luftwaffe day-activity against strategic bombing and tactical support of German ground forces. The night-fighters make up the difference of the 60%-40% in favor of strategic defense.

Oh please.  Your original assertion was:

"In all other fields of combat the altitudes were far less, usually below 15k feet....With the Normandie landings the primary task of the Allied air forces changed, with the RAF and USAAF being tasked to support ground forces, interdict enemy forces and conduct airfield denial operations. Quite suddenly Allied fighter pilots went from having to fight at nose bleed altitudes to having to dodge church spires.

From the summer of 1944 onwards the air war in the west changed to the same type of air war that had been fought everywhere else since the start of the war...."


Lancs flew higher than 15k.  The air war in the West didn't suddenly become the same low-altitude fight as the air war in the East. 

It sure did, and Lancs generally did not fly above 15k.

[Chalenge]

General Echols (The Man Who Won World War II) talks about the need for superchargers (they used to call them turbosuperchargers) so they can get to higher altitudes faster:

http://www.youtube.com/watch?v=KFwwgbj9Bi8

I'm sure we spent all that time, effort, and labor on superchargers so we could fight down low, right? 

[MiloMorai]

They use to call them turbosuperchargers because they were of the GE type as used on the B-17, P38 and P-47.

When the P-51 (supercharger) began to replace the P-47 (turbosupercharger) doing escort duty, the P-47 was sent to the IXth AF, a tactical force supporting the army.

[Old Sport]

Every where I look the service ceiling for the P51-D is listed @ 41,900 . Why is it that in this game the plane flattens out and become pretty useless at 30K?      

I do not know, but could it have to do with 100 octane avgas in AH, vs 150 octane in R/L by mid '44 ?

Best.

[Chalenge]

They use to call them turbosuperchargers because they were of the GE type as used on the B-17, P38 and P-47.

When the P-51 (supercharger) began to replace the P-47 (turbosupercharger) doing escort duty, the P-47 was sent to the IXth AF, a tactical force supporting the army.

We're not talking about mudhens here. We are talking about fighter pilots.

[MiloMorai]

We're not talking about mudhens here. We are talking about fighter pilots.

So you are saying mudhens, ie fighter bombers, never shot down enemy a/c?

[GScholz]

I do not know, but could it have to do with 100 octane avgas in AH, vs 150 octane in R/L by mid '44 ?

Best.

Increasing octane rating does not make your engine perform better at higher altitudes. When the Allies introduced 150 octane fuel it actually reduced the full pressure height of the P-51D from 24,500 feet to 21,200 feet. The limiting factor is the blower, not the fuel.

[GScholz]

General Echols (The Man Who Won World War II) talks about the need for superchargers (they used to call them turbosuperchargers) so they can get to higher altitudes faster:

http://www.youtube.com/watch?v=KFwwgbj9Bi8

I'm sure we spent all that time, effort, and labor on superchargers so we could fight down low, right?  

That propaganda film is from 1943; a time where the USAAF still believed in its strategic bombing doctrine. By the end of that same year the Luftwaffe had brought down the USAAF strategic think-tank from its lofty clouds at the cost of the lives of two-thirds of USAAF bomber crews in Europe.

Now let's disregard the propaganda films and quotes from unrealistic Generals, and look at what really happened.

The USAAF started its operations in Europe with the P47 which had a full pressure altitude of around 30,000 feet. It's long range companion, the P-38, also had a full pressure height of just under 30,000 feet.

When the P-51B/C started to arrive in late 1943 it had the Packard Merlin V-1650-3 with a full pressure height in high-blower of 29,400 feet. Very similar to the P-47 and P-38. However what did they do with the P-51D in early 1944, after they've learned the bitter lessons of 1943? They switched production to the Pacard Merlin V-1650-7; an engine optimized for medium-altitudes, with a full pressure height of 24,500 feet.

Now why did the USAAF do this? Because from costly experience they learned that it is no point in having your fighters' best performance at 30,000 feet if the enemy wasn't there. The high-blown V-1650-3 actually put USAAF pilots at a disadvantage at actual combat altitude against the Luftwaffe. So they lowered the full pressure height to an altitude band more comparable with their Luftwaffe adversaries. The introduction of 150 octane fuel also resulted in the full pressure height being further reduced to just over 21,000 feet.

Conclusion: The USAAF ended the war in Europe with a fighter that had its best performance at an altitude almost 10,000 feet lower than the fighters it started with. Your assertion that the USAAF strived for "higher and faster" fighter aircraft is wrong. Faster yes, but not higher, and that is an indisputable fact.

[Oldman731]

This is incorrect. The balance of claims indicate that there was an about 50-50 split in Luftwaffe day-activity against strategic bombing and tactical support of German ground forces. The night-fighters make up the difference of the 60%-40% in favor of strategic defense.

GScholz, thanks for spending the effort to look at these figures.  While the kill claims certainly aren't conclusive, they do add useful information.  I regret that I haven't had the time - and probably won't, within the life-span of this thread - to go over those materials.

That said, your conclusion here is broader than its supporting evidence.  You've found that the bulk of Luftwaffe claims from the units you studied (and why omit the Sudfront units, which would have flown against the 15th AF's strategic missions?), during the months you analyzed, were reported to have occurred between 3,000 feet and 15,000 feet.  That is consistent with both of our positions.  Eighth AF escorts often chased Luftwaffe planes (or were chased by them) to lower altitudes; 9th AF fighters were instructed to strafe German bases upon conclusion of their escort duties; and Luftwaffe missions sometimes were begun at and confined to lower altitudes.  We can only surmise that some of these Luftwaffe claims occurred during "tactical support of German ground forces" on the West Front, which, by nearly unanimous anecdotal accounts, was quite sparse except during the early Normandy fighting and for a few days during the Bulge.

- oldman

[GScholz]

We're not talking about mudhens here. We are talking about fighter pilots.

Yes, isn't it ironic that the high-altitude P-47 ended the war in Europe as a ground attacker?

[GScholz]

Oldman, the most telling statistic from that document is that out of 1033 claims by the tactical units only 35 were of B-17s or B-24s. Given that the Luftwaffe had orders not to engage escort fighters, the number of USAAF heavy bombers should have been dominant if these tactical units actually were used for strategic defense instead. Also, the kill claims of the Reich units are predominantly above 5,000 meters, and predominantly USAAF heavy bombers, in stark contrast to the tactical West units.

I omitted the Southern Front units because you claimed that "Luftwaffe activity on the Western front after the invasion was virtually entirely directed to opposing the Eighth Air Force". Well, The Mighty-Eighth did not operate in Southern Europe, and thus every singe Luftwaffe victory on that front would have supported my position. Since the Southern Front technically is not part of the Western Front I thought you would have surely protested had I included them.