Corsair vs. BF 109G,K or FW 190's

[Soren]

I know you're more knowledgable about the FW-190 than me Crumpp, but I have a leistung chart for the A-5 using C3 to run at 1.58/1.65ata. I'm sure you know which one I'm talking about.

Running on C3 at 1.58/1.65ata the power of the BMW-801D2 is 2,050 PS right ? So running at 1.58/1.65ata and weighing nearly 300kg less than the A-8 the A-5 should have a higher sustained load factor ?

As to the light version of the A-7, I remember reading about it as simply being a normal A-7 being lightened by the groundcrew (Removing the outer MG-151/20's etc.) and meant for use as a fighter interceptor, ei. meant to fight the Allied escorts.

[drgondog]

Originally Posted by Kurfürst

Please see below.



I am afraid this is incorrect, I trust Bill on this, and practically all publications I`ve seen say June 1944 for the P-51D as an introduction date.

I will have to do some digging but 200 in ops would be about right for late July - August.

For the 355th, the first P-51D-5 was flown on June 8 by Lt Col. Claiborne Kinnard in WR-A Man O War.. the 355th lost it's first P-51D in air combat over Warsaw on September 18 (Friendly fire from another 355 ship), and it's first to a German fighter on April 4, 1945 to an Fw 190D and last on April 7, 1945 - cause unknown - but probably a German fighter. In all, the 355th lost a minumum of three and maximum four P-51D/K to German fighters - all in four day span.

So, if you want to keep the playing field truely even, you need to find the first date by which at least 200 P-51Ds were in service with first line units, and, they suffered losses in combat. For the 109K, it`s November 2, even though it was in production since August 1944.


I think the 51F wasn`t introduced at all, or the p51H for that matter in the second half of 1944. I`d suggest you check out the new models of 109G that were introduced in the first half of 1944, especially the /AS types with methanol. By all accounts, these were excellent aircraft, and very close to the 109K in performance, albeit some 20 km/h slower due to their less clean airframes. Nevertheless, they stepped in for the 109K and DB605D since March 1944 as an interim solution.

The XP-51F was the first of the P-51H frame design, with only a couple of distinctions such as a much longer radiator/exhaust scoop aft of wing, than 51H and had the 51D tail.

You are correct about load factor reduction between the 51D/B and the 51F/G/H. It was reduced from 12 to 11 for ACM and 6 1/2 to 4 for landing.

Both the F and H had the same wing - slightly thinner than the D.

There`s much speculation in this and grossly underestimates development problems. Germany, who was desperate to stop the hordes of P-51s, P-47s, B-17s, B-24s, and Brit planes, with advanced aircraft, as you say, was developing the 109K since March 1943. How much easy it would have been for them to have it, one may say, by late 1943...? It`s certainly very easy to say - but in It took them until late 1944 until it actually arrive at the units, and it was far less radical departure from the existing G-airframes. Not to mention, that to my best knowledge, the F-series Mustang, as hot their spec are, are essentially experiemental aircraft that toyed with the idea of lowering airframe stress limits and weight in favour for higher performance. Apart from it never been realized in this form, it`s also questionable how much use such lightly stressed aircraft would be operationally, how many potential problems would be needed to be solved with the airframe and engine before it would be combat ready, how long it would take factories to re-tool etc.

In practice and in fact the P-51H had several design changes - specifically in tail structure beef up which actually delayed production introduction about 45 days (tail structure - fact, 45 days anecdotal conversation), but it had few problems in service from the very first production airfame.

Had the 51F been produced it would likely have increased weight about 200-300 pounds for combat airframe but still would have been the highest performing 51 and still stressed for 11G ultimate/7.4 limit vs the 12/8 for the 51B/C/D. It also would have less firepower and slightly less internal fuel.

I don`t like such speculations, and after all, the facts are on the table, we know how it was, anything else is a swamp of guesswork, riddled with dangerous intellectual traps every step. The 51F did not become an operational type just and the P-51H, which just missed the war, eventually did not produce the very impressive performance figures originally expected and calculated for it.

The USAAF flight tests were performed with extenal racks, whereas the NAA tests did not have them - which makes nearly 12 kts drag difference and would help explain the 21mph difference (487mph vs 466mph) result at Wright Pat - and it actually performed the NAA flight tests (clean) in very close agreement with predicted data..

Individual aircraft performance of course, differ from plane to plane, and it especially seems to be true w the Mustang.

.

True

[Crumpp]

I know you're more knowledgable about the FW-190 than me Crumpp, but I have a leistung chart for the A-5 using C3 to run at 1.58/1.65ata. I'm sure you know which one I'm talking about.

Hi Soren,

Thank you for the compliment.

Yes I have that report. The airframe is an FW-190A5 as is the WNr but that is where the similarity ends with a production FW-190A5.

That airframe is one of several airframes Focke Wulf used for factory testing. The engine is being tested with a ladedruckerhöhung and not C-3 Einspritzung. To achieve this simple manifold pressure increase, the engine required stronger pistons from the BMW801F series, a larger capacity fuel pump, lines/valve tapping into the manifold pressure regulator, Plugs, changes to the electrical system, and a new vorstellgetriebe to take advantage of the power gains.

None of these were available during the FW190A5 series production runs and there was no retrofit kit. However all serial production BMW801D2's came with the modifications as standard in June 1944. Until then only FW-190A8 production saw the modifications. So any surviving FW-190A5 airframe needing an engine after June of 1944, would have to have the new motor as a replacement or find old stock somewhere. This also means a completely new cowling, wiring harness, and other modifications. As the FW-190A5 did not have a universal harness I would think that Focke Wulf's airframe restoration program would be the only feasible way to receive a new engine with the modification. Of course this would mean it was rebuilt by the factory as an FW-190A8.

All the Best,

Crumpp

[Crumpp]

(Removing the outer MG-151/20's etc.) and meant for use as a fighter interceptor, ei. meant to fight the Allied escorts.

There is no noticeable difference in performance between a fighter with full wing armament and one with the outboard weapons removed.

This is why Focke Wulf discontinued manufacturing the fighter variant FW-190A series without the outboard weapons.

All the best,

Crumpp

[Crumpp]

In answering your original question about this - I've flown L-29s and on landing you are controlling sink rate with elevator because of the spool-up time of the engine and because of a very long flare if you do come in with power at that point you rely on the speed brake providing you're not on a short field...

OK guys, again sorry for going off topic....

Many of the early jets had to use this technique. That is why your choice of early jet operational airfields was limited.

Key part of your post is "at that point you rely on the speed brake".

All the best,

Crumpp

[Soren]

Thank you for the explanation Crumpp.

Now would it be possible for me to ask you to post the sustained load factors for the Bf-109K-4 (1.98ata) & Fw-190 Dora-9 ?

Thanks in advance

[drgondog]

Originally Posted by renrich

My reference show the P51 D with a sea level vmax of 367 mph, the P51B was slightly faster at SL. The F4U 4 was fastest of all at SL(US fighters) with Vmax of 380 mph. Same reference shows the P51D is introduced into the 8th AF in March of 1944. Same reference shows F4U4 could climb to 20000 ft in 6.8 minutes. Another reference shows the FW190D9 took 7min 6sec to climb to 19685 ft. The F4U4 was a significantly better climber.

Renrich - even if the phrase 'introduced' means someone in 8th AF was able to see one, perhaps the 51D delivered to RAF for testing, it would be tough to project as the first P-51D rolled off the production line in 'late March' according to Ray Wagner in "Mustang Designer". Gruenhagen talks about 'deliveries of P-51D in March' with no context.

The rule of thumb for the delivery to USAAF from factory to operational deployment at the squadron level was 6 weeks so Mid May would be an optimistic '1st mission' and early June (matching 355th and 4th experience) would sound right?

I have not yet heard back from Ted Damick but he is THE authority on 8th AF aircraft and data..

Regards,

Bill

[Crumpp]

Now would it be possible for me to ask you to post the sustained load factors for the Bf-109K-4 (1.98ata) & Fw-190 Dora-9 ?

The Spreadsheet is not designed to compare different aircraft but rather the same aircraft under different configurations. I made it for an advanced aircraft performance class.

It takes time to convert it from one aircraft type to another so give it a few days. It took an hour to convert to the FW-190D series.

So far I have the Zeke 52, Spitfire, P47, P51, and FW190 series done. I will have to add the Bf-109 to it.

All the best,

Crumpp

[davparlr]

Originally Posted by Kurfürst

I am afraid this is incorrect, I trust Bill on this, and practically all publications I`ve seen say June 1944 for the P-51D as an introduction date.

Two sources I have reference initial production delivery of March, 1944. “American Combat Planes” by Ray Wagner, and “America’s Hundred Thousand” by Francis Dean, which states that the P-51D was introduced to the 8th AF. This last reference does state that the P-51D was delivered to the 8th AF in quantity in June, 1944.

The 109K was introduced in during October, units received it in huge numbers already that month (some 200 were around, even though some were wrecked during refit). It was certainly in combat by the start of November since the first combat loss is known from 2 November 1944.

My reference states that the 109K appeared in November, 1944. The reference is excellent, but I think the difference is semantics.

So, if you want to keep the playing field truely even, you need to find the first date by which at least 200 P-51Ds were in service with first line units, and, they suffered losses in combat. For the 109K, it`s November 2, even though it was in production since August 1944.

I disagree. The proper indication of when aircraft development cycle is complete, which is what we are discussing, is the date of the first production unit, in this case, March ’44 for the P-51D, and October ’44, for the 109K. To be really fair, since the major changes of the P-51D over the P-51B is a bubble canopy and two added guns, you really have to go back to May, 1943, when the first production P-51B appeared, to get the right design genealogy. The 109K traces directly back to the G-10 (AS?) according to my reference. I have no reference (including your site) that references the production date of the G-10, except your reference of early ’44. If you have a more precise date of production start, I would like to see it. I didn’t trace the lineage to the G-6 as explained in the following paragraph. In any event, this would be a six to nine month difference.

To me a couple of months seems rather indifferent, and, there were plenty of 'interim' aircraft produced since early 1944 which ensured the 109K`s absance until October 1944 was not really felt - the K itself offered mostly just cleaner lines and more importantly, a standardized airframe with rationalized internal arrangements.

There appears to be a major redesign of the Bf-109 from the G-6 through the G-10 to the K. This is manifested in almost a 900 lb reduction in empty weight (6050 lbs vs. 5161 lbs). This is not a “just cleaner lines” redesign of the G-6. This is why I did not go back to the G-6.

I think the 51F wasn`t introduced at all, or the p51H for that matter in the second half of 1944. I`d suggest you check out the new models of 109G that were introduced in the first half of 1944, especially the /AS types with methanol. By all accounts, these were excellent aircraft, and very close to the 109K in performance, albeit some 20 km/h slower due to their less clean airframes. Nevertheless, they stepped in for the 109K and DB605D since March 1944 as an interim solution.

You are correct on the 51F as it was really a XP-51F, but it and the “G” incorporated the major changes implemented in the H. Since the changes to the P-51 were in the same scope as the Bf-109G-10 (including the reduction in airframe weight including reduction in armament (two gun on the G-10?)) and the same time frame (early ’44), it is indeed reasonable that the very capable North American engineers could have fielded a viable aircraft by October ’44. After all, they were able to take the highly advanced new design P-51 from drawing board to first flight in only few months. In reality, the Bf-109K was to the Bf-109G-6 as the P-51H was to the P-51D. Airframe was lightened and ammo and fuel reduced and bigger engine installed (did the Bf-109H only have two guns like the G-10?). In addition, the changes were in same time frame; the only difference was that the pressure to replace the P-51D was small. A fair comparison is the Bf-109K to the P-51H.

There`s much speculation in this and grossly underestimates development problems. Germany, who was desperate to stop the hordes of P-51s, P-47s, B-17s, B-24s, and Brit planes, with advanced aircraft, as you say, was developing the 109K since March 1943. How much easy it would have been for them to have it, one may say, by late 1943...? It`s certainly very easy to say - but in It took them until late 1944 until it actually arrive at the units, and it was far less radical departure from the existing G-airframes.

Not true. There was a 889 lb reduction in empty weight from the G-6 to the K. There was only a 540lb reduction between the P-51D and P-51H. Which one was more radical?

Not to mention, that to my best knowledge, the F-series Mustang, as hot their spec are, are essentially experiemental aircraft that toyed with the idea of lowering airframe stress limits and weight in favour for higher performance. Apart from it never been realized in this form, it`s also questionable how much use such lightly stressed aircraft would be operationally, how many potential problems would be needed to be solved with the airframe and engine before it would be combat ready, how long it would take factories to re-tool etc.

The weight reduction was to reduce what the British considered over-design of the P-51D by incorporating the design loads of the Spitfire. To my knowledge, there was no complaint about the Spitfire being too lightly stressed to be an effective fighter. Remember the Bf-109G-6 lost more weight than the P-51D did.

I don`t like such speculations, and after all, the facts are on the table, we know how it was, anything else is a swamp of guesswork, riddled with dangerous intellectual traps every step. The 51F did not become an operational type just and the P-51H, which just missed the war, eventually did not produce the very impressive performance figures originally expected and calculated for it.

I don’t think test results support this statement

Individual aircraft performance of course, differ from plane to plane, and it especially seems to be true w the Mustang.

I don’t think this is exceptional. There certainly is more information available over a wider time frame on the P-51 performance than for German designs.

I prefer this one for the P-51D Performance since it notes that 'the data presented represent good agreement with most of the flight test results'. It`s probably a good middle-value.

It shows 368 mph at SL, and I presume the wingracks are missing (I could be wrong), which chopped some 12 mph off from top speed and were std fitting. With them it would do about 356 mph, and there`s also a test with the RAF`s TK 589 which I have which had 354mph at SL (w. racks).

I'll accept 368 mph.

The one you shown, with 375 mph claimed at SL at the same rating of 67", from June 1945, is very much higher than that. I can only guess why - perhaps an exceptionally good aircraft was tested, and/or it was polished and had special surface treatment. But I doubt it`s normal (and so do even North American, see above), it`s probably the best figure around.

The associated write up on the test indicated one wing rack per wing was included in the “clean” design (remember, you were assuming the wing racks were missing). While no modifications were mentioned regarding making it more slick, I wouldn’t be surprised if gaps were filled, gun ports covered and maybe some wax. I would be surprised if the German test were not performed with similar modifications.

The 109K had 1800 PS in it`s earliest engine that was not fitted to too many aircraft though, or 1850 or 2000 PS. With the two latter ratings, it was officially rated at 370mph and 377 mph respectively, and some 8 mph if polishing was applied.

So, you are saying that the 109K, generating roughly 200 hp to 350 hp more than the P-51D (remember the P-51D engine is generating 1630 hp at 67”), can only eke out 2 to 9 mph more (using your figure for the P-51, no racks). By the way, did the 109K have wing racks on during the test? Doesn't this basically proves my point.

And of course, as in the case of the Mustang, there were worser and better planes. The tolerance was usually 3%, so theoretically you could have a production 109K anywhere between 360 mph (a plane w. the lowest rating, so badly built it just passed acceptance tests) and ~395 mph (a plane with the highest rating, with exceptionally good finish, polished by the loving groundcrew).

You seem to assign the P-51D data to the highest of the variance (your original argument was that it was the norm) and the Bf-109K to the norm of the data, when, it seems, you only have one point of data to work with on the 109K. I don’t think this is a statically valid assumption. It could very easily be the top of the performance range.

In any case you can view the whole thing on my site, here : Kurfürst - Performance of 8 - 109 K4 and K6 with DB 605 ASCM/DCM This is the only thing, I dare say, most if not all of us aircraft geeks have on 109K performance.

Thanks for the site. I will get busy trying to interpret charts and convert metrics and update my data base.

[Soren]

Originally Posted by Crumpp

The Spreadsheet is not designed to compare different aircraft but rather the same aircraft under different configurations. I made it for an advanced aircraft performance class.

It takes time to convert it from one aircraft type to another so give it a few days. It took an hour to convert to the FW-190D series.

So far I have the Zeke 52, Spitfire, P47, P51, and FW190 series done. I will have to add the Bf-109 to it.

All the best,

Crumpp

Can you post the work you've finished so far ? Would be really interesting

[Glider]

Originally Posted by Soren

Can you post the work you've finished so far ? Would be really interesting

Can I second that request please.

[renrich]

Bill, Sorry for my misleading post about P51D deployment. I should have looked further. I am glad to see that Dav has what I consider as a thorough and comprehensive reference on US WW2 fighters, "America's One Hundred Thousand" and it states the June 1944 date as to when P51Ds began to reach the 8th AF in quantity.

[Crumpp]

Here is the FW-190D9 using B4 and the Oldenburg system, clean configuration overloaded fighter at Take Off Weight:




Here is the FW-190D9 using C3 and MW50, clean configuration, overloaded fighter at Take Off Weight:




Here is the P47D-22 at Combat Weight = 60% fuel remaining at overloaded clean fighter configuration:




Here is the FW190A8 at Combat Weight for a clean configuration overloaded fighter:




Here is the FW-190A8 at Take Off Weight, Overloaded fighter with ETC 501 rack and 115 Liter Auxillary Tank/propeller weights:




Here is the Zeke 52 at Take Off weight:




All the best,

Crumpp

[drgondog]

Dave - the first P-51D-5, 44-13260, was the 7th Mustang off the Production line and reached the 4th FG on June 2. The 44-13300 was badly damaged by flak on June 7 and salvaged after Belly Landing at Manston (Goodson)

44-13305, 279, 302 were delivered to 355FG on June 5 but did not fly ops until June 8.

The 44-13260 was the 8th P51D-5 manufactured t Inglewood and so far I have not been able to find a -5 between 260 and 279 assigned to 8th AF. The block starting with 300 all the way through 900 were largely devoted to 8th and 15th AF. The fact that I can't yet find an earlier delivery than June 2nd does NOT mean it didn't happen - just that I can't find an occurance yet.

Ted is researching when the first D's came to Britain and into 8th AF Depots for 'combat mods - radios, etc). I also don't know if they (the first) came by surface transport or flown in by Ferry Pilots.

Regards,

Bill

[FLYBOYJ]

Originally Posted by davparlr

I disagree. The proper indication of when aircraft development cycle is complete, which is what we are discussing, is the date of the first production unit, in this case, March ’44 for the P-51D, and October ’44, for the 109K. To be really fair, since the major changes of the P-51D over the P-51B is a bubble canopy and two added guns, you really have to go back to May, 1943, when the first production P-51B appeared, to get the right design genealogy. The 109K traces directly back to the G-10 (AS?) according to my reference. I have no reference (including your site) that references the production date of the G-10, except your reference of early ’44. If you have a more precise date of production start, I would like to see it. I didn’t trace the lineage to the G-6 as explained in the following paragraph. In any event, this would be a six to nine month difference.

Just a note; I remember reading somewhere that there were late model P-51Bs and Cs (Dallas Built) that had a field conversion where the bubble canopy (Not a Malcolm Hood) was installed in the field basically making them "Ds." If I remember correctly these aircraft along with the first production "Ds" did not have the dorsal fin just in front of the vertical stabilizer. T.O. 01-60J-18 installed the dorsal fin.