FW-190 D-9-13 vs. Ta-152 C

[spicmart]

The frontal area advantage of the DB603 would count for nothing if it were mounted with an annular radiator, as per Fw190D. Especially if it was QEC designed to fit on the same mountings as the BMW QEC.

AFAIK an annular radiator (Fw 190D) is much less draggy than a radial engine with similar diameter. I guess it has quite less drag than one ought to think. The Fw 190D was more steamlined even than a Spitfire according to Bryan Bury's site about the Dora.
But this site does not exist anymore.

 

[Siegfried]

The frontal area advantage of the DB603 would count for nothing if it were mounted with an annular radiator, as per Fw190D. Especially if it was QEC designed to fit on the same mountings as the BMW QEC.

I don't think that even with the frontal radiator that the drag produced was a great deal: despite the appearance of being a flat area it was porous and the installation must have recovered heat energy using the ram (or so called meridith) effect; note the cowling cooling flaps which would have acted as nozzles.

The BMW801 comes in as a heavyweight: I suspect this is due to the armoured cowling oil tank cooler and the intergral cooling fan and gearbox.

 

[tomo pauk]

Agreed for the most part, just a tidbit: ram effect mean that incoming air has a beneficial influence at supercharger system (the air enters the intake at high speed, making it easier for the supercharger to compress the air), while Meredith effect is connected to the radiator it's ducts, in order to reduce/cancel the drag.

 

[riacrato]

I don't think that even with the frontal radiator that the drag produced was a great deal: despite the appearance of being a flat area it was porous and the installation must have recovered heat energy using the ram (or so called meridith) effect; note the cowling cooling flaps which would have acted as nozzles.

The BMW801 comes in as a heavyweight: I suspect this is due to the armoured cowling oil tank cooler and the intergral cooling fan and gearbox.

Even without Meredith effect the D-9 airframe produces a lot less parasitic drag compared to the A-model, at least according to VSAero models that were shown in this forum.

 

[Siegfried]

I'm having a difficult time getting a grasp on the differences, and the reason for the differences, between the FW-190 D-9-13 and the Ta-152C.

Bronc

Essentially the Ta 152C had a new bigger wing achieved by extending the roots with a new structure, this reduced wing loading and handled the extra weight. This was Kurt Tanks 'escort fighter'. The Ta 152H added more wing span still, something that reduces roll rate and speed but increases ceiling and reduces turn radious. Both of the new wings had room for much more armament and prodigious fuel volume in 6 bag tanks one of which could carry MW50. The FW 190 generally did not carry fuel in the wings. The fueselage of the Ta 152 was significantly rearranged and also seems to have had provision for more fuel volume, it certainly was the first aircraft designed from the begining for GM-1 (Nitrous Oxide)

The Ta 152C used the DB603LA while the Ta 152H used the Jumo 213E1, both engines had about the same performance, the DB603LA was lighter and did not come with GM-1 as standard. Both could use MW50.

I believe both new wings used twin steal spars with mich of the rest wooden. The stall and aeroelastic characteristics would have been completely different to the FW 190 due to the way the wing twist under load and the greater geometric twist (washout). The stiffness of the FW 190 helped give the aircraft its fast roll rate but also made its stall a littpe harsher as wings didn't twist under load to soften the stall.

The FW 190D series was a straighforward adaption of the FW 190A8 with the BMW 801 radial replaced by the Jumo 213A, there was a slight lengthening of the tail with a 'plug' inserted in the tail to provide the extra tail momment for handling the longer nose. In other words much easier to manufacture.

The Jumo 213A used 87 octane B4 fuel and had a single stage supercharger and was left over from descheduled Ju 188 bomber production and had to be used up but in an ideal world the Jumo 213C would have been used for the FW 190D9. The Jumo 213C had the mounting for a propellor and guns that allowed a motor canon and also used C3 fuel for 2000hp. It was a fighter engine from the start.

The Jumo 213A receive several field upgrades: a rich mixture injection system that boosted power from 1770 to 1900hp on B4 and then the oldenberg MW50 system that used supercharger pressure to pressurise the MW50 tank and blow the mixture into the supercharger. Junkers shortly after that sent field technicians to install its even more powerfull high flow pumped MW50 system for even more power. Use of C3 fuel added even more power. (This all happened over 2-3 months or so FW 190D9 performance is all over the place). This was a very fast aircraft at low altitude.

The FW 190D12 and D13 varied as to whether they had Mk 103 of MG 150/20 motor guns. They were powered by the Jumo 213E, Jumo 213F or planned Jumo 213EB engines (oversized valves) which had two stage 3 speed superchargers and so much better high altitude performance. Speed about 455mph. There were no synchronised MG 131 guns as the motor hub 20mm guns was enough.

Some variants of the FW 190D13 (I think the R3) were to receive wing fuel tanks, presumably taking up the space no longer needed by the outer wing guns. The 3 x 20mm guns being enough.

It was recently discovered that the Goetz Yellow 10 FW 190D13 had hydraulically boosted ailerons which was to be incorporated into the TA 152.

Eric Brown mentions that the roll rate of the FW 190D was less, I suspect this is inertial coupling of the longer body; the hydrauic boost should have more than made up for that.

 

[vanir]

Dietmar Hermann's book on the Ta152 mentions centre of gravity issues in Focke Wulf test documentation and company meetings, the Dora frame has one front, one centre/rear tank, both a good size. The Ta152 was to add the wing fuel cells and put a large MW50 tank in the rear fuselage for the C series, the H series was to put a GM-1 tank in the rear fuselage and use the inner port fuel cell as a small MW50 tank.

But they found centre of gravity issues in the V6 prototype when an ETC rack was fitted to the fuselage and ballast was used to represent production trimming (motor guns weren't fitted to prototypes, etc.). Future test guidelines were to leave the rear fuselage tank empty and use only the front tank. Fun part, none of the prototypes had fuel cells fitted to the wings yet. The fuel cells were to be fitted during production, the Ta-152H-1/R11 that were delivered (but not the V series 152H prototypes), they had fuel cells in the wings. And the end result of Ta-152 testing was that the rear fuselage fuel tank was to be removed for CoG issues and MW50 fitment relocated to the port wing in a smaller tank than planned.

Production series Ta-152C-1 would be delivered from June 45 and have 5 wing fuel cells, a small MW50 tank in the port wing, plus the front only fuel tank of a Dora, and an ETC rack fitted standard from the factory like an A-8. Overall fuel capacity is only marginally better than a Dora but cruise range is actually much better because the 603LA is far more efficient especially at altitude.

The D-13, which is much like the one Brown tested (his dora was a D-13 and not a D-9 but nobody knew what one was at the time, it was the one sent to the Smithsonian afterwards so it got examined later and the two-stage 213F motor and hand finished build quality was revealed, so Browns Dora evaluation no longer relates to D-9 in service trim but there is a superb one done by Wright-Patterson by two different test pilots and compares a regular service D-9 against the Mustang as a measure). Anyway the D-13 uses a shorter, lighter version of the basic 213E motor, it lacks the intercooler (oddly enough the 213A is actually a derivative of the 213E as well rather than the other way around, a simplified blower was put on for rushed production whilst development of the multiple stage one continued).

The power egg for the DB-603LA and Jumo 213E is actually the same size and roughly the same weight in its armoured cage, fully assembled and ready to start up. A Jumo 213F is going to weigh in similarly to a DB-603E. The whole Dora Tank, Daimler Jumo thing are all fairly interchangeable specifications on the same basic model design. They're all variations on a theme.

What you're really asking is why use the Dora when you've got the Ta-152C or vice versa.

Given the period, jets were coming onto the scene and the RLM was looking to downsize production to a smaller number of models capable of performing a wider variety of roles and continuing postwar service. They were headed in the same direction history took us. The Ta-152C represents postwar models like the SeaFury and P-47N where the Dora is more like an interim such as Tempest V and P-47D.
But production realities meant that historically it was easiest to use the aircraft available and use the Dora as a cheaper and easier build to quickly supplement the Ta-152C in the same way the G-10 was designed to do this for the K-4.

So putting improved engines in Doras to put up alongside Ta-152C was the best option. It was planned that the D-12 and D-13 were going to switch to DB-603 engines and be redesignated D-14 and D-15, to further close the gap between Ta-152C and Dora performance during 1945. But the aim of this was to gear down piston fighter production to be replaced by jets over coming years. Not overnight, but moving in that direction.


As for a performance comparison, I have FW charts comparing the D-12 with the 213E engine, to the Ta-152C with the LA motor (it's a mid-44 document so figures are obviously calculated), it gives the Dora/Jumo much higher performance under 5500 metres but from this height the Ta-152C/Daimler just owns it. In theory it is at least 20km/h faster at higher altitudes but in practise it could be as much as 50km/h or more as the complicated Jumo blower proved unreliable at high altitude, documented in Dietmar's book.
It was a similar problem with the P-47 and Spit HF models, in that era flying as high as people claim these aircraft run around was far more special case and dealing with astronautical research than they realise. Such heights were sustained only under test conditions or highly unusual and risky incidents, and even then the technology was rudimentary. The Thunderbolt turbo oversped above 9000 metres. Tank was the only pilot who got the Ta-152H anywhere near its claimed ceiling. HF Spits did top 40,000ft but under test conditions. Cabin pressurisation was at its infancy and incapable of pressurising a cabin in the modern sense, it's best achievement is keeping fumes out of the cockpit but pilot conditions were atrocious, with Saharan interior temperatures and unreliable sealing. Actual mission heights were in the order of 5000-8000 metres maximum. Luftwaffe Me-109 and Ta-152H tended to freijäger or orbit at 7000 metres according to wartime accounts, Germans just considered it a fairly safe ceiling height. I suppose because the majority of fighters perform best under 6000 metres.

Generally high altitude performance in service fighters, such as quoting absolute ceiling (well beyond the climb rate related service ceiling, typically around 6000 metres for midwar types), are one figure in a question of performance mapping, best used to infer things like cruise range and loadbearing for a quantity of fuel. Aircraft comparisons deal in performance envelopes.

The Jumo performs superbly up to 8000 metres and the Daimler to 10000 metres in practise so Daimler has a better cruise range and better loadbearing, that's the moral of that story.
The Daimler hardly notices the extra weight of the stretched Ta-152C, pilots remarked it was more stable and had more lazy grunt. Both engines gave the impression they could climb to space at a good rate.
The Ta-152C frame spreads its weight out very nicely along a torsional line and keeps the same frontal mass, so it appears to be less affected by a much larger weapons load. It is rated for heavier loads than the Dora, is much better armoured and even the prototypes all had four MG-151/20 fitted/with ammo ballast all through testing, its performance is rated for carrying a much heavier warload and combat trim.

It is literally the conclusion of exactly what the Dora was trying to achieve, which is logical the Dora is its interim type rushed into production. It is heavier but more refined, like most later versions of an earlier model craft tend to be.
The main thing about production realities for service issue is that all were based on current Anton production airframes of the same period, Ta-152 were in production terms more heavily modified Doras, so it was easier to keep numbers up continuing Dora production and upgrading their engines. Make them alongside Ta-152, the RLM planned to replace all 190A/F production with Dora/Ta152 production, and all other fighter production would concentrate on transitioning to jets.

 

[Siegfried]

As far as Altitude performance goes: the Jumo 213E was equiped with GM-1 on the Ta 152H while the DB603LA and the Ta 152C was not.
A DB603LA equiped Ta 152H with GM-1 should perform better than a Jumo 213E?

Also in the pipeline was the Jumo 213EB (oversized valves I believe) and the 4 valve head Jumo 213J which ran at 3750 rpm for 2700hp.

 

[vanir]

I talked with Dietmar and some of the people at LEMB at length on this and got sent tons of documentation, I was the one who did the Ta-152C-1/3 flight modelling for the aaa/sas il2 repatch and they helped with the research, was nearly a year long project. Got V7 spot on though, I did a DB-603EC Nov44 spec V7 that tops 615km/h at sea level fully loaded, plus the C-1 and 3 production series (Dietmar sent me a bunch of stuff on the changes).

Was doing a ton of DB-605 and Fw-190A research back then too. Talked to Crumpp. A lot of stuff I just get told in passing though while I'm researching something else, so sometimes I'm running on fallable memory.

And of course I'm just one of you guys, open to correction.

Anyway the tested performance using GM-1 was a rather serious problem with the pressure actuated blower system on the Jumo. The GM-1 threw it all out and instead of getting a boost for every gear above the throttle altitude, the third gear keeps kicking back to second with the GM-1 activated. Kurt Tank himself was the only pilot who didn't have this problem, nobody else could get it past second blower gear with the GM-1 enabled, which means actual flight ceiling was restricted to 12500 metres because of unreliable engine performance. On top of this there were problems with the cockpit pressurisation system that caused a service ceiling limitation of 10500 metres after it nearly killed one pilot. So this was the Ta-152H true absolute ceiling which was the same as a Ta-152C. You never got to use the GM-1 because of the pressurisation system failure. It was actually removed from all Ta-152C and Me-109K-4 which were also supposed to be pressurised. The technology was just too rudimentary, it didn't even work properly in the Spit recon thing, unsafe above 40,000ft for any extended period. All they did which was useful, they kept fumes out of the cabin at high altitude, that was the usual killer at around 10,000 metres. Interior/exterior/engine bay ambient pressures cause fuel and exhaust fumes to do laminar flow over the airframe and enter the cockpit, even crappy pressurisation prevents it, true story. But in the 1940s the best cockpit pressurisation you could get short of building a B-29 wasn't nearly capable of preventing your blood boiling at 12,000 metres, another true story.

In terms of a comparison Jumo-Daimler yes you're right Siegfried, the LA on B4 has 1000m more throttle height than the 213E on B4, and more importantly the GM-1 will use the monstrous Daimler slipping blower instead of the sensitive and troublesome automatic gears in the Jumo. They don't like second stage blowing let alone GM-1. The Daimler doesn't mind it at all, it adds a good two thousand metres throttle height in the 300kg standard kit. That means the Daimler-LA is putting out something like 1800PS at 12000 metres, which is what a Jumo-E/F puts out at 8000 metres.
Lot of weight but.

 

[davparlr]

But in the 1940s the best cockpit pressurisation you could get short of building a B-29 wasn't nearly capable of preventing your blood boiling at 12,000 metres, another true story.

Blood does not boil at 12000 meters. Pressure suits are not required on military aircraft until over 50,000 ft (aprox 16,000 meters)

 

[vanir]

well to be fair it varies by thickness of atmosphere layers, which are dramatically less over the poles and different over northwest europe than the pacific for example, but quite right dave, I just pulled the figure out of a hat based on altitudes I know intake pressures markedly differ, not actual accounts of blood boiling.

 

[davparlr]

It must be noted that at about 40,000 ft. pressure breathing is required.

 

[vanir]

Modern civilian airworthiness prefers pressurisation over 30,000...or less.

 

[spicmart]

...but there is a superb one done by Wright-Patterson by two different test pilots and compares a regular service D-9 against the Mustang as a measure.

What was the conclusion of this comparison?

 

[davparlr]

Modern civilian airworthiness prefers pressurisation over 30,000...or less.

I believe USAF requirements are that unpressurized aircraft are limited to 25,000 ft, the crew must wear masks above 10k, I think. However, if a pressurized aircraft loses pressurization above 40000 ft., the O2 regulator will provide 100% O2 under pressure to the crew masks. In other words the mask actually blows O2 into the lungs, which is what I meant by pressure breathing.

 

[vanir]

What was the conclusion of this comparison?

The pilot worked harder but could match Mustang performance but here is the important part, build quality was shocking. It had to be rebuilt before the aerodrome would even declare it airworthy enough to test fly. Both pilots commented that it was more like a hotrod that was built in a shed than a mass produced fighter plane, they said the main accomplishment of the type was that it could match Mustang performance and yet was so rough and nuts and bolts to fly.
It was a real hack. But also a real dragster.

This is more of a statement of German industry of the period, war records make the same comments about G-14 build quality in mid-44, those made in Hungary were better built. Hartmann rejected a replacement plane because of its shocking build quality and requisitioned a 1943-build G-6 from a training squadron.
It was also suspected that the Dora had been assembled by camp labourers, passively sabotaging with poor quality (unairworthy) work. To hold together under those conditions is a pretty impressive aircraft design basis.

 

[vanir]

I believe USAF requirements are that unpressurized aircraft are limited to 25,000 ft, the crew must wear masks above 10k, I think. However, if a pressurized aircraft loses pressurization above 40000 ft., the O2 regulator will provide 100% O2 under pressure to the crew masks. In other words the mask actually blows O2 into the lungs, which is what I meant by pressure breathing.

thanks for the extra info mate, I was playing a bit but recognise clearly you're more knowledgable on the topic than me I pull figures from the air mid stream y'know, they have basis but aren't necessarily as well informed as others, especially on experten sites like these.

 

[davparlr]

thanks for the extra info mate, I was playing a bit but recognise clearly you're more knowledgable on the topic than me I pull figures from the air mid stream y'know, they have basis but aren't necessarily as well informed as others, especially on experten sites like these.

Just trying to remember operational days long past. Good discussion on oxygen usage, though.

 

[vanir]

If I was paranoid I'd think the post above me was telling us to get a room davparl

 

[jim]

The pilot worked harder but could match Mustang performance but here is the important part, build quality was shocking. It had to be rebuilt before the aerodrome would even declare it airworthy enough to test fly. Both pilots commented that it was more like a hotrod that was built in a shed than a mass produced fighter plane, they said the main accomplishment of the type was that it could match Mustang performance and yet was so rough and nuts and bolts to fly.
It was a real hack. But also a real dragster.

This is more of a statement of German industry of the period, war records make the same comments about G-14 build quality in mid-44, those made in Hungary were better built. Hartmann rejected a replacement plane because of its shocking build quality and requisitioned a 1943-build G-6 from a training squadron.
It was also suspected that the Dora had been assembled by camp labourers, passively sabotaging with poor quality (unairworthy) work. To hold together under those conditions is a pretty impressive aircraft design basis.

Did they use Mw50 during their "comparison tests"?
Were they familiar with german systems and tuning them ?
The pilots had to work harder despite the presence of automatic engine controls?
Did their report imply that a proper built dora could perform better ?
Their expertise and eperience were better than Eric Browns ?

 

[jim]

Was Ta 152C relly needed? In my opinion NO. It was a classic example of german overenginnearing and misjudged operational needs.
LW had Me 262 as a bomber destroyer , Ta 152H as mid/ high altitude fighter ( while being amble even at low altitude) . What Lw lacked was a low/medium altitude air superiority fighter to support the army on BOTH fronts and help in Reich Defence against Jabos.
Performance is the premium criteria for any fighter. Since Dora and Ta152C were able to use the same engines weight would show the winner
Ta 152C was much heavier. Was that weight worth the performance and manouverability loss ?
The excessive weight was caused by :
1) Longer fuselage . That was nessacary because Lw demanded 20mm cannons in place of 13mm nose armament,and Mk 103 30mm motorkannone ,plus 20mm or even 30mm cannons in wings! That was an overkill of unbelievable proportions and immense weight penalty. The 3 x20mm Of Fw 190D-13 ,placed on or near the central axis is enough even for B17s .If a pilot cannot shoot down aircrafts with such armament its problem is not the armament but its training. R4M were on its way too.
Longer fuselage was needed for intercooler space too but a two stage ,intercooled engine was not a must for a medium altitude fighter. Also Db engines provided decent performance even with single stage supercharger.
2) Additional fuel . More fuel is always good dut the wings tanks of Ta152c could and would be introduced to the Fw190D13 as well
3)Much heavier navigation and blind weather equipment . Bad weather missions should be a job for a plane based on Ta 152H . No matter what avionics Lw fighters carried , German controllers were continiusly unable to properly direct them. In fact put them directly into escort fighters path. So at least save some weight for the dogfights. Also for the eastern front totaly useless
4) Stronger airframe. Because of the requirement of the redecilus armament. Fw190A8 was already very strong ( more than ideal for a pure fighter)
5) Slitly bigger wing. That was a good thing without important weight penalty .Dora would be helped by this wing ,as it would lower a little wing loading and would help with stall ( the inexperienced pilots)
For the above reasons i find the weight of of ta152 unjustifiable
In My opinion the ideal configuration for a late war medium altitude Fw
1) Dora fuselage 2) Ta152c wings 3) Db603 EC , Jumo 213F , Jumo213S or J or anything else available in this performance class, Db 603L if space permitted is 4 ) 3 x 20mm armament 4) Boosted ailerons as found in D13, integral engine cowling ( built in a single Ta 152H ,150 004 ,and improved aerodynamics), 5)wide blade propeller tuned for turning and climbing, 6)improved less druggy radiator, 7)very high pressure Mw50( Mw100?), 8)Ta 152 vertical stabilizer, 9) fuselage gaps sealed 10) F8F surface built quality ( i dont claim it possible, i just call it ideal!)
I used Mr Hermanns book on Ta 152 as a basis, not an ideal book but thats what i have.
Please correct any mistakes