Fw-187 could have been German P-51?

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I don't believe it.

Heavier shells tend to retain velocity over a longer range. Hence the reason 3.7cm flak has over twice the effective range as 2cm flak even though both are high velocity weapons. BK 5 should have been accurate to a range of at least 2km. And it's a foregone conclusion that a single 5cm mine shell will seriously damage any aircraft.
 
I don't care if you don't believe it. Look it up.

Aiming is major limit on air to air shooting, ie predicting were the target will be when the shell gets there with NO rangefinder and calculating gun sight like many AA guns had.

Unless you use a two seater Fw 187 with this poor soul sticking his head and shoulders out of the cockpit to range on the B-17s.

 

What a load of nonsense that Wikipedia article and the website it cited.
"Were said to have shot down 129 B-17s and 4 B-24s"?
No, far from it: here's what really happened:



pages 32 - 33:




The smaller, faster firing Mk 103s and MG 151/20s were infinitely more efficient because they could actually hit a target, whereas the BK 5 was very fortunate if it hit anything; it worked maybe once or twice when fired at unescorted bombers by pilots who were "outstanding marksmen". The BK5 was even worse when tried in two converted Me 262s and would have equally been a waste of time in the Fw 187.
 
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I only use that example because I happen to be in Madrid at the moment!

Hola! I thought your post had a distinctly continental flavour to it; all that talk about the Spanish Inquisition (cue the Monty Python jokes )...
 
smaller, faster firing Mk 103s and MG 151/20s were infinitely more efficient because they could actually hit a target,

Your article talks about using BK 5 cannon against fighter aircraft. What results were achieved vs an American heavy bomber box (i.e. what they should have been used for)?
 
So you think some 4 months from idea to production is a very long gestation period? What is your definitation for a short gestation period? One can say that Mk VIII suffered from a long gestation period but not Mk IX.

Juha
I do not think it was that short. If you look at "Spitfire, the history" There are at least four sections, each of several or more pages concerned with changing the size and area of the empennage to increase stability on each of the new planes with more blades on the prop(s). While it may have been only four months from idea to first flight of the Mk-IX. Page 307 of said book disputes your claim of service 4 months after idea. First flight in September 27, 1941 and by April the next year, they were still testing it and ordered a second airframe conversion to speed testing. It was in test for nearly 6 months, in spite of the go-ahead already given. They were building plane that were not fit for service due to many handling defects. Read the whole chapter if you doubt this. The Mk-XIV was much worse. Taking more than a year of test, modification and more tests between first squadron service and first kill. The Mk-V during this time, September '41 to April '42 lost 335 planes a number that forced them to abandon all operations not in defense of England. Pilot complaints about heavy controls, bad manners and "Snaky" Yaw tendencies are rife. The Spitfire never regained it's sterling reputation after the Mk-V became obsolete. The Mk-IX became better than good enough, but was never equal to the Mk-V as related to fighting qualities. The Mk-XIV was an unmitigated disaster on those lines, but was the only plane the Brits had that could hope to compete late war, so they flew it anyway.
 

Missed the part with the book recommendation. Could anyone please post it again so I can have a look? Thanks.
 

It seems the Authors of "Spitfire, the history" do not agree with you. Start on page 307 and keep going until you get to the part where they changed the tail size.
 

Well, yes it is. Fitment of a heavier engine reduces static CoG margin and makes the plane vertically unstable. The four blade prop required to put the power into the air added area forward of the CoAP and made the plane "snaky". Those problems took a long time to solve when they were encountered. Those problems were over looked in large part because of the dire need of more performance than the Mk-V could give. So no matter what you do when, it takes a long time to fix each generation of power increase. That is what the problem is.
 
Steam cooling was the darling of the 1930's, right when the Fw 187 was designed and built. A normal radiator system uses a closed liquid system, typically ethylene glycol, and runs from about 30°C to about 95°C, a difference of 65°C that can be used for cooling.

I don't know of any steam systems that are not evaporative. Some were surface evaporative but all made use of the heat of vaoporization, and used condensers to turn the steam generated by the engine heat back into liquid. The temperatures were usually measured in the liquid sections, one in the line going back to the accumulator tank from the condenser (the colder one) and one inside the engine before the liquid is turned into steam (the hotter one). The two temperature extremes are usually about 80°C and 110°C and it seems the system is less effective, but when the liquid turns to steam, the temperature is 560°C. So the temperature difference is 580°C, quite effective at generating a temperature swing.

Personally, I don't know of any gasoline engine cooling system that uses steam other than an evaporative system. I am not even sure if another type exists. If it does, I don't know about it. If you turn liquid to steam, the system IS evaporative. If you turn it into steam and it never gets back to liquid until you shut the engine off …. maybe it is a closed steam-cooling system, but I don't know of any engine that could be cooled by steam entering the liquid intake port.

A steam separator is a device used to separate water from steam. That implies the steam remaining is used for something, and there is NO use for steam in cooling any engine that is colder than the steam. ALL engines are colder than steam.

I think the "steam separator" is a German-to-English translation error. To achieve cooling, the steam must be condensed back into a liquid if it is a CLOSED sytem, or else you are flying a LOSS system. Some Reno racers fly a total loss cooling system for the oil, but I cannot conceive of Focke-Wulf trying to palm off a total loss system for the Fw 187. When the water runs out, you go down. If I had fuel left, I'd not want to crash due to running out of water!

When the Fw 187 book arrives, I'll be interested to see the DB cooling system description and the purported reason why the Fw 187 was not proceeded with. If it WAS politics, then the Third Reich was almost as stupid as we seem to be today. Not surprising in the least except for the fact that Hitler was a dictator and politics should not have been a disabling thing for his government.

Perhaps it was endemic to the procurement arm of the German military? It certainly reared its ugly head in the US procurement system ... both during and after WWII.
 
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do the math. A bomber traveling at 200mph covers about 400ft in the time it takes between shots from the BK 5, the firing aircraft, if doing 400mph covers 800ft. It takes about a second (or more?) for the shell to travel 800 meters, the bomber covers about 300 ft (four fuselage lengths) in a second. The 400 mph fighter covers around 600 feet in the same time.

This is like trying to shoot flying ducks with a rifle from a pick up truck driving faster than the ducks.

Most people figured a pilot was doing good if he could keep a target in the gun sight for 3 seconds. Even if we credit the BK 5 with with being able to fire 3 shots in 3 seconds ( it can, 2.66 seconds from 1st to 3rd) we run into the other statistic that says on average the pilots hit with 2% of rounds fired. To get a hit the pilot with the BK 5 either needs to hit with 33% or rounds fired or needs 16-17 firing passes to score a hit. Or gets one hit every 2 1/2 missions with a 21 round magazine capacity.

With two MK 103s firing 39-40 shells in 3 seconds the pilot on average will get one hit on 4 out of 5 passes.

An Me 262 was firing 40 shells a second or 120 in 3 seconds so, if close enough, scored 2.2 hits per 3 second firing pass.

Now some pilots were much better and made up for the pilots that emptied their ammo tanks/bins without hitting anything but setting up a plane that needs an extraordinary shot to make ANY use of what soever AND degrades the performance of the plane at the same time makes no sense.
 

Why not just install the big engine with annular radiators like those on the Ju-88 and be done with it? There was no down side to frontal area. Little downside to Form factor and huge increases in power.
 
I like the aerodynamics of the FW-187. It has a higher aspect ratio wing, low form drag and less SA/power as shown by it's quick climb rate and speed on so little power. The very small differences in the weight of the two engines makes consideration of same a moot point.
As I see it, the plane had two big problems, low power for the time and a crummy cooling system. It also had a huge and insurmountable problem with the RLM. Little to nothing maters if you can not solve this last thing.
 

IMHO you should read pp 307-08 again, Mk IX was at first in essence Spit Mk VC locally strengthened with Merlin 61 bolted in its nose. Spit Mks VII/VIII were the propertly developed Merlin 60 series Spits but because their development to production ready took time and air situation was critical, the ad hoc solution was Mk IX. 4 months was an underestimation say 5. But after all this isn't a Spitfire thread, so if you want to discuss on Spit maybe it would be better that you open a new thred.

On handling IIRC Quill wrote that of the Spit fighter versions he liked Mk VIII most .
 
I have been taught over the years that simple engine swaps can be calculated with little difficulty. First, the Square Root of the difference in power changes speed proportionally. Secondly changes in weight do the same, also as a second order function. The big bugaboo is the extra weight of the engine must be offset with ballast, if there is not enough room in the aft fuse to move something heavy back some distance. If you do these things, you get a good idea of the changes in speed. Climb is harder but goes up as a first order fraction. ( More power = more climb.)
In this case there is a third problem in that the original cooling system did not work and the new one creates more drag. Beyond simple math's.
 


Spitfire Mk IX Performance Trials




Spitfire IX Tactical Trials





Spitfire Mk XIV Testing

To summarise, the IX handled very much like the V. The XIV handled very much like the IX, except for take-off where the stronger torque of the Griffon made life more difficult.

Basically, in 1944/5, when you could get it to the fight, the Spitfire XIV was the aircraft to have for the Allies in air to air battles in the ETO. The problem was getting it to the fight.
 
A steam separator is a device used to separate water from steam. That implies the steam remaining is used for something, and there is NO use for steam in cooling any engine that is colder than the steam. ALL engines are colder than steam.

Hello GregP,

the steam seperator in german called Dampfabschneider, was part of the engine, and it's main duty was to hold the water liquid circle of the engine bubble free, so that no steam bubbles could get at the water circle of the engne.
It was also used for normal high pressure water cooling at the DB 605, Jumo 213 and DB 603.
The first german engines as the Jumo 211A-H (Jumo F was the first with high pressure water cooling) and the DB 601A-N (DB 601E as the first with high pressure water cooling)were not high pressure water cooling engines and the part of the glycol was very smal and at the jumo engine only part of the water cycle at winter month. The engine highest temperature of the non high pressure water cooling engine was 90 C, for the high pressure water cooling engines 110-120 C. It was higher at the second generation engines with steam seperator.
 
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I was think of Mk108 cannon.

IMO high velocity 3cm Mk103 cannon does not belong on a WWII era fighter aircraft. CAS aircraft are a different matter.
My landlord when I was stationed in Heidelberg claimed to have flown and used a Me-109K with the Mk-103 in it. He had pictures of him and the plane. Willy Messerschmitt also made that claim in his book that several were made and some used for test and evaluation.
I think that disputing the head of the factory when interviewed just after the war would not be easy to prove. What higher source would know what they were doing. On the other hand, no one thinks the records from that time are very good, if they exist at all. So that is one best possible source and one not so great source, disputed by record that have be demonstrated to be less than reliable?
 

Is this mythical, fictional circle of pilots like your "former landlord who flew a Me-109K with a 30 MM Mk-103 shooting through the prop hub and two Mg-151/15s under the cowling!" ?

Modify the B-17 into night bomber/low altatude streak bomber?

btw:
Mk 108 - 1057mm long, 58kg.
Mk 103 - 2350mm long, 141kg.
 

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