If the RAF had been defeated in the Battle of Britain

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The range of an individual aircraft is not truly representative of its range on operations. The map posted earlier showing the range of the Bf 109 is true for a plane flying in peacetime alone. In practice having to form up with the bombers, weave around keeping station with them and then going in to combat meant that on London raids the bombers had almost no escorts left at all.
 

Assuming the following specs, I get a Breguet Range of ~800 miles. It's plausible that the BF-110C has a real-world range of 646 miles without reserve. What are the performance specs of the earlier Jumo-powered BF-110?

Given
Gross Weight - 14,366lbs
Fuel Capacity - 354 gallons
Wing Area - 413 sq.ft
Aspect Ratio - 6.83
Cruise Altitude - 20,000ft
Cruise TAS - 322mph (235mph IAS)
Horsepower @ Altitude - 1726hp

Estimated
Zero Lift Drag Coefficient - 0.0258
Oswald Efficiency - 0.75
Engine BSFC - 0.53 lb/hp*hr
Propeller Efficiency - 85%
L/D @ Cruise Altitude - 8.33
 

I like the sound of that operational concept. One can imagine a coordinated effort to hammer 11 Gp in the south and then, when some predetermined degree of attrition has been achieved, initiate the sub attack on Scapa Flow. Those would be 2 pretty sizeable body-blows to British prestige, not just internally but across the British Empire and also with then-neutral countries, most notably the US.
 

According to battleofbritain1940.net, the planned invasion had three phases:

1) Luftwaffe conducts probing attacks on Southern English coast and interdicts English Channel shipping.
2) Destroy the RAF via BF109s clearing the airspace, bombers destroying airfields and Stukas taking out radar.
3) Conduct amphibious landings along breadth of southern English coast.

Those Junkers flaps are also quite prone to icing up in weather. Bluntly, the more you read about German aircraft design the more you realize how overrated their designers are.

The Luftwaffe couldn't exceed phase 2 because their aircraft were not competitive. The BF-109E was outclassed by the Spitfire I. In hindsight, the choice to run an inverted engine, motor cannon and structurally optimized landing gear seriously hampered the design. The German tendency towards complex solutions for simple problems (e.g. wing slats, direct injection, electric propeller pitch control) just slowed them down further.

IMO, the Germans would have been much better off if they had licensed the Wright Cyclone like the Russians and dumped all their development efforts into that engine family. All the Luftwaffe's needs could have been met had they had entered the war with the 9 cylinder in service, the 14-cylinder undergoing trials and the 18-cylinder in development. Putting those engines on austere, efficient and easy to build air frames would have given them a highly competitive air force until the jet-age. Of course, there's the risk they'd just make them overweight and needlessly complex like the BMW-801...
 
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The Bf 109E was not outclassed by Spitfire I.
Inverted engine and motor cannon (that 109E was never outfitted in-service) don't have anything to do with choice made for the landing gear. Take a look at He 112 and 100, or Ki 61. The Bf 109 prototype, as well as other competitors, was powered by an up-right V12 engine, without provision for engine cannon. The techincal items you mentioned served the purpose, Luftwaffe was more slowed down by lack of funds (Germany vs. UK and France combined, or even vs. UK only) and trained manpower than it was by unsuitability of it's hardware to be mass produced.


Talk about self-inflicted wound if they went with Wright Cycone. Gives them 320 mph Bf 109 instead 350, and 300 mph Bf 110 instead 320-330 mph. Plus more fuel used for same distance travelled. Better allow BMW to continue with the BMW 117 V12 engine of 36 liters, might have actualy powerful BMW engine in service before the BoB.

The M82 was a new development (crankcase, cylinders, crakshaft, supercharger, carb, reduction gear, crankpins...), not just the Cyclone somehow turned into 14 cylinder radial. It needed 95 oct fuel, unlike what most of German pre-1942 engines used.
 

That was the limited objectives of Directive 16.
  1. The English Air Force must be so reduced morally and physically that it is unable to deliver any significant attack against the German crossing.
  2. Mine-free channels must be cleared.
  3. The Straits of Dover must be closely sealed off with minefields on both flanks; also the Western entrance to the Channel approximately on the line Alderney-Poitland.
  4. Strong forces of coastal artillery must command and protect the forward coastal area.
  5. It is desirable that the English Navy be tied down shortly before the crossing, both in the North Sea and in the Mediterranean (by the Italians). For this purpose we must attempt even now to damage English home-based naval forces by air and torpedo attack as far as possible.
As a matter of historical fact the Germans never came close to achieving ANY of those five points.

This was superseded by the far more wide ranging Directive 17 which gave the Luftwaffe a list of tasks it could never have accomplished with the means at its disposal.

1. The German Air Force is to overpower the English Air Force with all the forces at its command, in the shortest possible time. The attacks are to be directed primarily against flying units, their ground installations, and their supply organisations, but also against the aircraft industry, including that manufacturing antiaircraft equipment.

2. After achieving temporary or local air superiority the air war is to be continued against ports, in particular against stores of food, and also against stores of provisions in the interior of the country.

Attacks on south coast ports will be made on the smallest possible scale, in view of our own forthcoming operations.

3. On the other hand, air attacks on enemy warships and merchant ships may be reduced except where some particularly favourable target happens to present itself, where such attacks would lend additional effectiveness to those mentioned in paragraph 2, or where such attacks are necessary for the training of air crews for further operations.

4. The intensified air warfare will be carried out in such a way that the Air Force can at any time be called upon to give adequate support to naval operations against suitable targets. It must also be ready to take part in full force in 'Operation Sea Lion'.

5. I reserve to myself the right to decide on terror attacks as measures of reprisal.

6. The intensification of the air war may begin on or after 5th August. The exact time is to be decided by the Air Force after the completion of preparations and in the light of the weather.

It was to defeat the entire RAF, it never defeated 11 Group, not just prevent attacks on the invasion operation.
Then there was a list of other objectives never even mentioned in the earlier directive.
It was to destroy the RAF's infrastructure, the British aircraft industry and other parts of the wider armaments industry. It was to enforce a blockade on British ports and destroy food and other supplies, both there and across the country.

Furthermore, in the detailed planning for Sealion, it was to support large scale airborne operations, support the amphibious landings and protect the invasion fleets!
The Allies did all this on D-Day with 12,000 aircraft at the end of a campaign lasting years which had reduced opposition from the Luftwaffe to as close to zero as to make no difference. The Luftwaffe was supposed to do it with a fraction that number of aircraft and in a few weeks.....it's ridiculous. It couldn't be done, and adding drop tanks or allowing a few fantasy aircraft makes no difference to the fundamental equation.

Cheers

Steve


 

I'd disagree slightly with your analysis in one respect. While the overall objective per #1 was to defeat the entirety of the RAF, item #2 provided some scope for achieving local air superiority which could be interpreted as over the 11 Gp AOR.

Now...all that said, the above list of targets is so broad in scope and so poorly defined as to entirely prevent any reasonable assessment of progress or declaration of success. A more focused directive to eradicate the RAF's radar and C3 infrastructure as part of a phased operational-level campaign would have provided much-needed clarity in terms of expectations, ability to execute, and evaluation of success.
 
The LW attitude to the chain home RADAR has never been fully explained as far as I have read. It is obvious from their range and position that their field of view overlapped. That being the case the LW had to disable a minimum of two stations and best to make it four to guarantee making the system blind. The chain home system was far from secret, the failure to tackle it or understand its significance is ...well it is strange in hind sight.
 
Perhaps they didn't quite appreciate how the British air defense system worked at the time, It seems a few British commanders didn't even though they were operating within it.

Early warning is just that, Early Warning. It doesn't fix tactics or poor gunnery or grand tactics (big wings) or a host of other aspects of air defense.
 

"Strange" only if one presumes that the Luftwaffe's analysts had made an accurate assessment of its value. While I don't think the Luftwaffe's analysts were stupid, I don't think that they were superhuman, either. The Luftwaffe had also been on a winning streak, including against the RAF in the Battle of France, and saw some spectacularly poor tactical decisions on the part of the RAF, e.g., some of the uses of the Fairey Battle
My suspicion is that the Luftwaffe had been winning, largely through superior tactics against significantly weaker opponents, they underestimated the technological capabilities of the British and the British ability to get a new technology into a significant operational role. Don't get me wrong: I think the German war planners were largely competent, but competent doesn't mean infallible.
 
I'm sure steve will give a more complete answer, but it is incorrect to assert that the Germans had no knowledge of radar detection or GCI techniques. They practiced it themselves. What I think came as a surprise was the level of integration and sophistication worked into the RAF early warning system. It was this non-technical aspect to the way information was organised and passed to the people that mattered that the germans failed to appreciate adequately.

Within a year the Germans were organising a bigger more sophisticated and more effective system for early warning of their own
 

We know the fuel tank capacities of the Fw 187.
There is no doubt as to Dietmar Herman's range figures for the Fw 187.

1 The Fw 187 V5 (ie DB601 version) had an internal fuel capacity of 1250 liters and the Me 109E series 400 liters.
2 The Fw 187 V5 thus had 625 Litres of fuel to feed each DB601.
3 The Me 109 E7 thus had 400 Litres of fuel to feed its one DB601.
4 The Fw 187 thus had 400/625 = 1.55 times more endurance and range at the same power setting.
6 Given the Fw 187 significantly greater speed at the same power ratings the range should be at least 1.55 times that of the Me 109E. Since the Range of the Me 109E or F is usually given as 410 miles (660km) we can see the 1200km range for the Fw 187 is realistic.

A DB601 producing 1100hp and consuming fuel at 0.210KG/hp is going to consume 308L an hour. Those are official DB figures I'm using fro combat power.

The Jumo 210 engined version of the Fw 187 had 1110 Litres of fuel disposed in 620L fuselage tank and 2 x 245 wing tanks.

The DB engine version of the Fw 187 had 1300 Litres of fuel disposed in 880L fuselage tank and 2 x 210

Worse case, if Focke Wulf has to get the Fw 187 in production without increasing its capacity gives us 1110 Litres of Fuel ie 38% more per engine than the Me 109E/F which substantially out ranges the Me 109 and the slower Me 110.

I agree regarding the 1350hp DB601H having a 1 minute rating of 1350hp being not operationally possible in 1939 but even with 1050hp, the same as the Me 109, is speed is not going to fall below that of the 109.

Below page 63 of Dietmar Herman's book you alluded. You can see the two aircraft have equivalent armament with differences trivia. Typo aside on the 12 instead of 2 MGFF 20mm guns.



The Bf 110C range variations isn't really relevant because it was an ineffective escort with rare exception when sent ahead of the bombers to disrupt enemy fighters and when it was effective it was too expensive. Nor is its 20% variation in range with regards to altitude important. The salient imprtant fact on the Fw 187 is that its range should be (worst case) 38% more range or 80% than the Me 109 with the improved tank-age.

Most German combat aircraft have their range given in terms of range at maxim sustainable power. This was about 880hp for the DB601A followed by 1/2 at combat power which is not WEP but another rating allowed only for 30 minutes (typically) 0.210 Kg of fuel per hp per hour is a good figure to use. No reserves for anything but warm up and climb.

Only the Fw 187 would have had the range and performance to take on the Hurricane and Spitfire over most of Britain.

The opportunity to develop it wasn't taken.
 
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The Luftwaffe had at least 8 Freya radars in service in Germany at the outbreak of WW2 in September 1939. By the Battle of France they had introduced 20 more (some sources say they had 20 in total in Service.) This might explain the Luftwaffe willingness to move their fighters to forward bases and thereby leave the German interior undefended.

In addition they had used a portable Freya units in Czechoslovakia as early as 1938 and latter air transportable units in Norway.

In addition they had both ship and a few shore based Seetakt units at naval bases. The Willhelmshaffen raid was detect both by a Luftwaffe Freya and a Naval Seetakt. The operators contacted each other to confirm their bogies.

During the British retreat from France the German army captured several British radars. The British Force had 17 Transportable Radio Unit (TRU) and several were captured. These units operated at 6m and 50kW. They would have appeared primitive to the Germans but their portability would have convinced them of the impossibility of knocking out British radar. There were backups to Chain Home.

Furthermore Chain Home Low CHL was fully integrated by the so called Battle of Britain.

Hence knocking out the British radar system would be impossible. Goering or whomever usually get blamed couldn't have done a thing, there were too many backups to Chain Home (CH), including Chain Home Low (CHL) and TRU.


By August 1940 they had introduced 20 Wurzburg A units into the Ruhr Valley. The units lacked conical scan, that came in with Wurzburg C in Feb 1941 and they also lacked synchros to transmit data to the FLAK computer (that came in with Wurzburg D and Wurzburg Riesse in June 1941) but could locate an aircraft with 2 degrees by wobbling the dish. These are service dates I'm quoting.

The Freya's were integrated into the existing Luftwaffe air reporting service so its wrong to say they weren't part of a system designed to intercept hostile aircraft. Radar was just another sensor along with observers, sound locators and radio direction finding.

The State of German IFF was more wanting. The system they used was initially was called FuG 25 Zwilling and was more intended to inform a FLAK radar that it might be tracking a friendly. Unfortunately it worked by returning an audio tone when triggered by the radar changing pulse repetition frequency so it could have been triggered any aircraft in the Beam. The superior FuG 25a Erstling only came latter, probably 1941, and gave a second distinct pulse adjacent to the reflection pulse when interrogation was turned on.

The infamous and deadly "Battle of Barking Creek" in Sept 6 1939 caused by inadequate IFF shows the RAF didn't have its systems fully developed yet.

The Germans were well aware of British radar and their own radar was better in some ways. Several unprofessional British historians tried to maintain the myth that they, the British, had developed radar probably as a matter of British pride and as an act of disrespect to former foes. This has lead to a lot of false and bad history. Obviously these attitudes were given up but their echoes persist. I think the Great Watson-Watt, who had so much to play in erecting Britain's early Radar, annoyed the shit out of the Americans at GE developing SCR 268 and 270 with his unwelcome advice on a system that inevitably was going to be invented in several countries at the same time.

"Deflating British Radar Myths Of World War II" by Major Gregory C Clark Notes Air Field Marshall Joubert was conducting meetings as to whether the Germans had radar at all as late as Feb 1941.

Rather famously the Germans had developed blind navigation and bombing systems under the British radar so to speak.

It is true that the British had a well integrated system because it was older, it initially only had to operate over sea.

1 The Germans knew of British radar
2 They knew of its use because they had their own systems.
3 German IFF was less developed but they had a sense of the problems of IFF and had started experimenting with a system in November 1939 called "Zwilling"
 
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The Germans understood what the Chain Home stations were, and had an idea of their capability. What the didn't understand was how they were integrated into a quite sophisticated air defence system.
They had no inkling of how this was organised. If they had there would have been no need even to attack the Chain Home stations, which were difficult targets anyway. They could simply have concentrated all their effort on the Sector Stations, and attacked them repeatedly and relentlessly, as often as weather permitted. It was Sector Control which controlled all the air defence systems, from barrage balloons, to anti-aircraft batteries, to interceptors. The Observer Corps also reported to them rather than Fighter Command's Filter and Operations Room at HQ. Destroy them and everything above them (Group Control and Fighter Command HQ) is irrelevant, and everything below them is blind. Of course, Sector Stations were sometimes attacked as part of overall operations, and, when significantly damaged, was the one thing that really worried Park.

The Luftwaffe was still arguing about the necessity for radios (or should that be wireless) in fighter aircraft when the British were using them to control their interceptions.

Cheers

Steve
 
We know the fuel tank capacities of the Fw 187.
There is no doubt as to Dietmar Herman's range figures for the Fw 187.

I wasn't doubting the range figures of the Fw 187 much, but the range figure given for the Bf 110 is total nonsense, or a major typo.

Since the Range of the Me 109E or F is usually given as 410 miles (660km) we can see the 1200km range for the Fw 187 is realistic.
here were get into another bit of confusion. The 109F should have had better range than the 109E since it was faster on the same power?
Granted not enough to be escort fighter. However the 109F might be a better drag model (power to speed) for estimating performance of the FW 187 with normal DB 601 engines?

This is one area the book doesn't cover. It jumps from the Jumo 210 powered versions through the V5 with the experimental engines (not just cooling system) to the flights of fancy with DB605s and BMW 801s.

I agree regarding the 1350hp DB601H having a 1 minute rating of 1350hp being not operationally possible in 1939 but even with 1050hp, the same as the Me 109, is speed is not going to fall below that of the 109.

Never said it would fall below the 109, just pointing out the lack of data, real or estimated for a service Fw187 using engines (and guns) that were actually in service at the time in question (1930-40)

Below page 63 of Dietmar Herman's book you alluded. You can see the two aircraft have equivalent armament with differences trivia. Typo aside on the 12 instead of 2 MGFF 20mm guns.

The difference is not so trivial. I included the picture to show why. The weight of the two extra MG 17s and their ammo is trivial. The extra drag may not be. If you want to estimate the performance of a theoretical FW 187 using DB 601A engines lets start with the closest version to the service aircraft we can, not an under armed prototype, or the estimated speed of such a plane using estimated ram effect and estimated exhaust thrust. Why is there a 15kph difference between the speed in that chart and other figures for the FW187A-0?



The range variations are important to show that the "snapshot" of the FW187s capabilities vs the BF 110 are in error. By how much is in dispute. But if the actual range difference between the two planes is actually close it helps explain the reluctance of the Luftwaffe to shut down a production program in progress and try to convert to a new type of aircraft right before a war.

I would note that FW did a much better job with exhaust thrust than Messerschmitt did even if the 13% figure is a bit high.

If you want exhaust thrust to work the gases have to exit the pipes flowing about 180 degrees to the airplanes direction of travel.
The exhaust on the left is just getting out of the cowl, not much else. The exhaust on the right is being deflected so the exhaust goes under the wing rather than flowing into the wing leading edge?
On DB powered 110s the outer exhaust pointed up and over the wing(kept the hot exhaust out of the radiator) while the inner exhausts pointed down and under the wing. Messerschmitt managing to get the exhausts of both engines pretty much inline with the wing.
 
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If you wanted to understand what the Germans understood of the British system you would have to understand how the German air reporting service worked and how well the Germans had integrated their own radar. Their ability to comprehend the RAF system would depend on their own.

Condor Legion was using radios in many of their aircraft and they saw value in it. If they were questioning the value of radios in the Me 109 perhaps it is because they thought that interception was a job for the Bf 110. After-all the Bf 110 was supposed to smash up enemy bombers and the observers other duties were to operate the radio and take navigation fixes.
 
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It was the 'Spaniards' who were so opposed to the use of radios in fighters. Steinhilper has some severe criticism for the old hands, 'Spaniards', and in particular Galland over this issue in his account of the period.
Cheers
Steve
 


Thanks, that's a nice illustration of the many minor mods that effect A/C performance.. Thanks for all of your informed information and insights especially on the technical issues.

I believe the main reason the Fw 187 is faster is because it is 1038kg lighter (3402kg empty versus 4440kg for the Me 110B) thats only 77% of the empty weight and 85% of the Gross weight( 4900kg vs 5701kg). It has only 78% of the wing area. (30.2 vs 38.55 m^2).

The length is also 10% less so I'm assuming that besides wing area that frontal area and whetted area is also about 80%-85% of the Me 110. That alone, applying a cube law, should make the Fw 187 5%-7% faster.

The Me 109F has 87 imp gallons of fuel (400 liters) and the Me 109E actually has 91 gallons (420L) so there is about a 5% fuel advantage to the E.

Its also quite possible that Me 109F (F1, F4) was calculated on a different power level. What appears in Messerschmitt or DB documents may not be authorized by the Luftwaffe. In addition there were different versions of the DB601A engines like the A, A1, AA and also of the N with different superchargers. I think early N's had an inferior supercharger. The differences are mostly minor but they effect critical altitude as well as power and WEP ratings. The AA I believe was an export version for the Swiss air-force that ended up in Luftwaffe aircraft.
 

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