Do-335 ILO the Me-210? A Proposal.

[davebender]

producing the Bf 109Z would bring you almost there with minimal effort compared to the complex pull/push design.

I'm not convinced the Me-109Z would be less expensive to produce nor am I conviced performance would be as good.

The Do-335 is going to roll a lot better due to having a single fuselage and both engines on the centerline. Overall high speed handling is likely to be superior as the Do-335 controls are optimized for 450 mph.

The Do-335 wingspan will present a smaller target.

The Do-335 will fly better with one engine shot out as both engines are on the centerline. 350 mph with 1 engine shot out is an outstanding performance and offers a decent chance to limp home.

Not that I am opposed to the Me-109Z. Perhaps an Me-109Z should participate in the RLM competition between the Fw-187, Me-210, Do-335 and Ar-240.

If the judges are fair I feel confident the Fw-187, Do-335 and Me-109Z will all score higher then the Me-210 as a long range fighter.

Burmese Bandit will be in charge of the aircraft weapons system. That way when we shoot the front propellor off he gets the blame.

 

[timshatz]

I could see it being very fast. Matter of fact, wicked fast. Couldn't see it as being much of a turner, but being a heavy fighter, it wasn't supposed to turn. Suprisingly, it has a fairly large wing area listed on Wiki. Given that and the weight involved, it had a relatively low wing loading for an airplane with twin engines.

 

[Milosh]

Good , if you have the book what does it say on pg 86?

Yet he specifically made mention of the rear engine, yet failed to mention the front engine. Thirty seconds seems an rather short time for an engine seizure, and would seem to indicate the rear engine cooling was marginal.

 

[red admiral]

In short, the Meteor didn't even come close. And excuse about the wing area was just that, an excuse. The drag added in level flight was far below what would have been the case if it truly was the wing area which caused the difference in speed alone. Larger nacelles of the Derwent engine quite simply caused a lot more drag than the narrower ones of the Jumo 004. Simple concept of area rule.

I don't see how you can completely ignore that report. Simply saying the British source is wrong is hardly a defence, especially when presenting no evidence to the contrary.

As for wing area, the figure in the report show very clearly that the disparity in wing area results in the major difference in drag.

Area rule doesn't come into it that much in this flight regime. You need to be going faster. The difference in top speed was from excessive wave drag caused by the short nacelles on the early Meteors. The longer nacelles added wetted area and increased drag in that way, but greatly reduced the wave drag, resulting in lower overall drag and a much higher top speed.

If you have evidence that says otherwise, please share it.

 

[riacrato]

I'm not convinced the Me-109Z would be less expensive to produce nor am I conviced performance would be as good.

The Do-335 is going to roll a lot better due to having a single fuselage and both engines on the centerline. Overall high speed handling is likely to be superior as the Do-335 controls are optimized for 450 mph.

The Do-335 wingspan will present a smaller target.

The Do-335 will fly better with one engine shot out as both engines are on the centerline. 350 mph with 1 engine shot out is an outstanding performance and offers a decent chance to limp home.

Not that I am opposed to the Me-109Z. Perhaps an Me-109Z should participate in the RLM competition between the Fw-187, Me-210, Do-335 and Ar-240.

If the judges are fair I feel confident the Fw-187, Do-335 and Me-109Z will all score higher then the Me-210 as a long range fighter.

Burmese Bandit will be in charge of the aircraft weapons system. That way when we shoot the front propellor off he gets the blame.

Considering how cheap a Me 109 airframe was by 1942 I doubt the Z airframe would be more expensive than a Do 335. And don't forget the tooling, training for workers and ground crew...

But by effort I primarily mean development. The Do 335 concept wasn't exactly standard thus development was plagued with a lot of new issues to tackle. The 109 was a proven airframe, basically everything is already in place. And calculated figures (yes I know...) show the Z to be pretty good.

In short, for a heavy interceptor, the 109 Z is imo the easier and less risky solution. Roll rate will be worse compared to the Do 335,as will be most other performance figures, but is it worth the effort and delay ? I don't think so.

 

[Bug_racer]

One thing I find interesting is that during the BOB the Hurricane was to take on the bombers while the Spitfire was to take on the fighters .

The Luftwaffe seems to keen to try and make an all round fighter to take on bombers and fighters which I dont think worked . There are just too many attributed in a plane needed to be able to fight a plane like a P-51D and take out a heavy bomber like a B-17 .

The Do-335 with 30mm cannons would have been best as a bomber destroyer . An Me-262 better as a fighter ?

Correct me if Im wrong ???

 

[davebender]

Dornier had 20 years experience producing seaplanes with tandem engines. That's good enough for me. I am confident that bugs with the engine cooling system and other such glitches would be quickly solved.

On the same topic.....
Why weren't the He-177 and Ju-288 bombers produced with tandem engines rather then coupling two DB605 engines together? You should get similiar aerodynamic benefits without all the mechanical problems and fire hazards.

 

[drgondog]

Dornier had 20 years experience producing seaplanes with tandem engines. That's good enough for me. I am confident that bugs with the engine cooling system and other such glitches would be quickly solved.

On the same topic.....
Why weren't the He-177 and Ju-288 bombers produced with tandem engines rather then coupling two DB605 engines together? You should get similiar aerodynamic benefits without all the mechanical problems and fire hazards.

Pushing that much weight aft for the second pair of engines in the same nacelle could have posed an insurmountable aft cg issue..

 

[Njaco]

On the same topic.....
Why weren't the He-177 and Ju-288 bombers produced with tandem engines rather then coupling two DB605 engines together? You should get similiar aerodynamic benefits without all the mechanical problems and fire hazards.

Heinkel tried and was expressidly told 'No' so he decided on his own and created the He 277 with 4 seperate engines, mainly DB 603A. But too late and only some prototypes were made. Goering got so fed up with Heinkel's incessant requests to make it that Goering finally forbid him to mention it (November 1941). Heinkel secretly ignored him and built the thing calling it intially the "He 177B". Heinkel finally convinced Hitler and they started the prototypes until all bomber production was stopped in favor of fighters.

 

[davebender]

Not the same thing. Like the Ju-290, the He-277 was a more or less conventional heavy bomber design with 4 tractor engines.

The Dornier tandem engine designs were unique.

 

[Marcel]

Hi Marcel,

From just looking at the illustration it seems that the Fokker used an aircooled engine, where'as the Do-335 used two liquid cooled engines. The tunnel intake only really works well with liquid cooled engines, where you have the radiator form a barrier between the air intake and outtake tunnel. The Do-335 featured a veyr large rear radiator with no less than 3 rear outtakes. The design was similar to that of the P-51.

Thanks Soren. Yes realised them being ait-cooled when I posted the pics. I had guessed they weren't as air-cooled inlines are not very common in WWII There was also a design of the Fokker using two Merlins, so judging from your info, this would have been a better option.

 

[Soren]

Good , if you have the book what does it say on pg 86?

No problem, I'll tell you as soon as I get home from work today. Although I admit I am abit curious as to what you are refering seeing as I remember having to start by going to page 133 yesterday to read his accounts on the Do335.

Yet he specifically made mention of the rear engine, yet failed to mention the front engine.

Geez, I wonder why?? Maybe because he can't really see if the rear engine has been hit as it's situateed way in the back; and if the rear engine has lost its' radiator then it would probably be kind of a good idea turning it off as there was very little ventilation around there if the air scoop had been shot up! You couldn't think to yourself that might have been why?

Thirty seconds seems an rather short time for an engine seizure, and would seem to indicate the rear engine cooling was marginal.

Erm, no it doesn't. If a P-51 had its radiator shot to pieces it would have around 30 seconds until seizure as-well. Are you claiming that the P-51 suffered from insufficient cooling of its' engine?

 

[Burmese Bandit]

Burmese Bandit will be in charge of the aircraft weapons system. That way when we shoot the front propellor off he gets the blame.

Hey!!!


Stop making me da scapegoat you...bender...you!!!

 

[davebender]

Herr Bronc needs to know who to kill when things don't work as planned.

 

[Soren]

Ok Milosh, I opened up Hans Werner Lerche's book and turned to page nr. 86. There's a bit on his transition from the FW44 Stieglitz to the Klemm Kl125, the first low wing monoplane in his logbook. And at the bottom of the page he talks abit about the Ar 66 and the Go 145.

Now Milosh, what in the world has this got to do with our discussion ??? Have you even got the book? I suspect not seeing how badly you interpreted his account of being attacked on page 136, trying to skew his words in order to prove your point.

 

[Soren]

Thanks Soren. Yes realised them being ait-cooled when I posted the pics. I had guessed they weren't as air-cooled inlines are not very common in WWII There was also a design of the Fokker using two Merlins, so judging from your info, this would have been a better option.

Agreed Marcel.

 

[timshatz]

Pushing that much weight aft for the second pair of engines in the same nacelle could have posed an insurmountable aft cg issue..

Definitely, flat spin heaven. Stalls could be tricky, might end up with instructions in the book to INCREASE power to the engines. Might be the only way to get the thing out of a flat spin.

 

[timshatz]

If a P-51 had its radiator shot to pieces it would have around 30 seconds until seizure as-well. Are you claiming that the P-51 suffered from insufficient cooling of its' engine?

A little tangent to this idea. You can make an engine last longer after it's dumped it's coolant (same with oil). Couple of things you do right away are:

1. Mixture full rich
2. Boost pump (if you have it) "on". If not, get going on the wobble pump.
3. Throttle back to lower/est setting
4. Cowl flaps wide open

Depending on a number of factors, you can keep the thing in the air, sometimes for quite a while. Losing your coolant/oil isn't an automatic death sentence for the bird (but it is very, very bad news).

(also, you are definitely sacrificing your engine to do this but it goes without saying)

 

[Soren]

Agreed timshatz, but without doing any of these exercises the engine wil sieze very quickly, esp. if the engine isn't subject to any cooling air, which naturally is the reason why Lerche quickly checked the oil/coolant temperature for the rear engine first. (Plus the fact that he could actually see the front engine) The front engine had the advantage of being directly inline with the wind, the annular radiator design ensuring that the front engine also got some cooling effect from the wind. The P-51, P-39 etc etc plus the Do-335's rear engine didn't have this luxury and were entirely dependant on the radiator staying intact.

 

[Shortround6]

The Dornier tandem engine designs were unique.

Not really, quite a few WW I bomber designs used them as did a number of aircraft in the late 20's and early 30's. Advantages were good streamlining (as it was understood then), keeping weights closer to the center line of the plane, keeping thrust lines closer to the center line in case of an engine out, and keeping mechanical parts localized. In the last case some of these planes offered in flight access to the engines for a mechanic.

Disadvantages include not only cooling, especially for air cooled engines, but a lower propulsive efficiency for the rear propeller in each pair. Once it was realized that there was a lot less drag if the engine nacelle was some what in line with the wing instead of under it or over it the tandem engine mount really lost in popularity. Of course this last doesn't apply to the Do 335 and with the distance between the propellers the Do 335 probably didn't suffer the same loss in efficiency that closer spaced engines did although there may have still have been a slight loss.