If the RAF had been defeated in the Battle of Britain (1 Viewer)

[tomo pauk]

According to spitfireperformance.com, the Spitfire Mk.I running 100 octane developed more horsepower, was faster at all altitudes, had equivalent climb rates to the BF-109E all at a lower wing loading. It also had better dogfighting armament in its 8x .303 wing guns, which had a high rate of fire, uniform exterior ballistics and a superior incendiary bullet. The Spitfire Mk.1 also had better visibility, was easier to fly, had a torsionally stiffer wing, a constant speed propeller and much more development potential.

I'm not sure that Spitfire have had torsionaly stiffer wing that Bf 109, at least not until late 1944/early 45 when Mk.18 emerged, or perhaps until Mk.21 emerged. 109E was rolling at much greater rate until 250 mph indicated speed, the Spitfire taking the slight lead past 320 mph indicated.
Bf 109E was much easier to enter a dive and keep the advantage. External ballistics of the MH FFM and MG 17 were close enough, the Spitfire was a bigger aircraft thus easier to spot and hit. Spitfire's (and Hurricane's) armament was far from perfect during the BoB, level of criticysm ranging from mild to harsh.
In order to be outclassed, the 'winner' need to trash the 'looser' by a wide margin. Talk Corsair vs. Zero, or Bf 109 vs. Hurricane. Not the case with Bf 109E vs. BoB Spitfires.

Even if the BF-109E had been the equal of the Mk.1, it wouldn't have been enough. The Spitfires had an inherent operational advantage by flying over home turf. The BF-109E needed to overmatch the Spitfire to win, which it did partially through tactics and pilot skill, but not in performance.

No quarrels about this. Germany needed far more assets and much different approach to kill the RAF in 1940, vs. what they have had historically.

I meant that each individual choice hampered the design, not that the engine and motor cannon resulted in poor landing gear geometry... even though that is partially true.
I think the unsuitability of their designs for mass production (trainers on up) made their lack of funds even worse.

Once again - the choice of engine layout and wepon layout have had no bearing on landing gear geometry; the prototypes for fighter competition were powered by up-right V12 without provision for engine cannon. Might also check out the He 112 and 110.
Germany ramped up production of military hardware as ww2 went on, granted some designs & choices hampered them in that area. Talk Me 210, He 177 or Jumo 222 flops.

I'm not suggesting the Luftwaffe strap an R1820 onto a BF-109 airframe, but rather a clean-sheet design. Single row radial engines are easier to build and maintain than V12s. With careful layout and detail design, I estimate that an R1820 powered fighter could meet or exceed Spitfire MK.IX levels of performance on 87 octane gas with roughly BoB level of technology.

Hopefully you will elaborate a bit on this.

The Ash-82 was a development of the M-25, which was a licensed copy of an early Wright Cyclone. My argument is that the Germans would have been better off had they followed a similar development path.

I don't think they would've benefitted at all, their war effort will receive an own goal with that scenario.

 

[pbehn]

As I understand it the Bf109 was easier to produce than the Spitfire in man hours, but the UK overtook Germany in production of S/E fighters in 1940 and retained that advantage until 1943. Germany actually wasn't on a 100% war footing in 1940 they underestimated UK production while the UK overestimated German production. There were 34,000 Bf 109s made in all marques as opposed to 20,000 Spitfires

From what I have read the comparative performance of the Bf 109 and Spitfire were quite close and not uniform. The Bf 109 was faster and had better climb at some altitudes and was slightly better in rate of roll and dive, close enough in most cases for the situation and pilot to be decisive. The RAF pilots envied the Bf 109 cannon, and the RAF did introduce cannon during the BoB.

 

[Shortround6]

Ok we are starting to get into the flights of fancy here.

3 pre producton aircraft is not really production any more than many of the US ""Y" series aircraft were "production". There being no real investment in jigs/fixtures that enable true mass production.

The Me 110 like the Me 109 lacked the range to have much of any impact except in a tiny South East part of England. The Fw 187 did have the range.

Actually the 110 did have a greater range than the 109, roughly 40-50% more, this would actually mean a slightly better than 40-50% increase in operational radius as the fuel needed to climb to altitude has to be taken out of the "nominal" range.

They also show how critical 100 octane fuel was to the viability of the RAFs defence operations.

This is a non-issue. Doesn't matter what the British had for fuel, they had it. Question is whether the FW 187 would have made any real difference in the BoB, not it would have IF...................

In actual combat these Fw 187AO were flown with the second seat position loaded with ballast. One can only imagine the fuel that could have been carried 400-500L litres? A massive camera?

Which is it? they needed ballast in the rear seat or you could use it as a fuel tank? Unless the empty tank weighs whatever the ballast did? (I am not saying the ballast had to weight same as a crewman.) Book says that the ballast was to allow 3 point landings. One also wonders what the radio installation was like. The book claims that initially the radio range was sometimes as short as 3km but with work they achieved the desired range of 60km. Great for a factory defence fighter, absolutely lousy for a fighter intended to roam over most of England, radio won't even reach across most of the English channel. Bf 110 used the same radio as the He 111. Took the extra man to operate it.

Only 100/130 octane fuel made the Spitfire faster.

there was NO 100/130 fuel during the BoB, None, nada, zip, zero.............
There was 100 octane and when tested later if proved to be around 100/115 to 100/120 the 100/130 came later. And once again, this NOTHING to do with whether the Fw 187 would have been a help to the Luftwaffe during the BoB.

Speed at Sea Level
Fw 187 A0 466kmh / 289.5mph with 2 x 700hp Junker Jumo 210G (87 octane)

Speed at 4600m (15,090ft)
Fw 187 A0 545kmh / 338.5mph with 2 x 700hp Junker Jumo 210G

Max Speed
Fw 187 A0 545kmh / 338.5mph at 4600m/15091ft 87 octane

Loaded Weight, Wing Area and Wing Loading
Fw 187 Weight 4900 kg /10802lbs, wing area: 30.2sqm, loading 162.25kg/m2

Still pushing the "estimated" speeds of the Fw187?
At least the British numbers are from actually tests even if service aircraft might not quite reach them.

The Fw 187A0 carried 1110 Liters of internal fuel which gave a range of 1440km, about 880 miles. If the second cockpit had of been converted to a 400 Litre tank one would expect about 40% more range Stripped of guns & excess armour with engines tuned it probably would have made a difficult to intercept recon. There was plenty of room for a camera in that seat position.

Man, what can of worms we have here. In regards to the bolded part. Is there any evidence what so ever that any of these FW 187 were ever fitted with armor? or self sealing fuel tanks? the last Fw187A-0 with Jumo engines (work number 1974) made it's first flight in Sept of 1939, at this time few, if any Bf 109s or BF 110s were equipped with armor or self sealing tanks. Strange that aircraft not intended for front line service would be? Please note that teh Bf 110 the British test flew was noted as NOT having the full amount of armor that currant or later versions had and that aircraft was in service in Aug of 1940, not the summer of 1939.
If you put the camera in the back seat you can't use the space for fuel. This is part of what I hate about discussing the FW 187, it seems to be made of rubber and can be stretched, twisted and compresses in any manner to suit the objective at hand without any regard as to how that affects the rest of the plane.

BTW nobody was "tuning" aircraft engines in WW II. Not like car engines were tuned.
Mechanics had about 3 modifications they could make to an aircraft engine in the field. They could change the type of spark plug. They could change the timing of the ignition, This gets tricky as most aircraft engines used fixed timing, unlike cars. What ever timing you used for the spark plugs at idle was what you had at full rpm, there is no advance mechanism. A few had retard system for starting. 3rd, on many (but not all) allied aircraft you could change the jets in carbs or throttle body fuel injectors (and the mechanic had really better know what he was doing) or change a needle. For the Germans there is no easy adjustment for fuel flow. A new set of injector plungers? Change the injector rack setting so more fuel flows at all rpm and altitudes?
For motorcycles and cars the exhaust was often "tuned" in various ways (less restrictive muffler, larger diameter pipe, different length) to be less restrictive or to use resonated pulses. If you are already using short stacks only a few inches long you don't have options to change.

The Me 110 received its first DB601 engine in late 1938. These engines weighed 580kg vs 440kg dry but knock on effects raised the weight of the sluggish Me 110B->Me 110C not by 140kg per engine but 200kg. Thus a 400kg increase or a 10% increase over the Fw 187 empty weight and 8% loaded and fuelled.

Hmm, only 60KG per engine for the "Knock on effects". Like the bigger props, the bigger radiators and coolant, the larger oil coolers and oil supply? Bigger engine mounts?
Something is beginning to smell.
See: Kurfürst - DB 601, 603, 605 datasheets - DB 601 A-1

I don't read German so perhaps I am in error but there seems to be two weights given for the DB601A-1 on that data sheet.
A dry weight (if google translate is correct) of 610KG and an equipped (with accessories?) of 715kg.

I would note that the numbers on Page 68 of the book for the Bf 110b-0 don't add up well. The difference between the empty weight and gross weight is only 1261kg but the fuel load (1270 liters) is 965kg and after you take out another 200kg for crew (100kg per man including parachute) you have 96kg left for engine oil and ammo. This assumes that the 4440kg "empty weight" is empty equipped (guns, radios and a few other bits included).

If you are comparing "empty" to "empty equipped" you are going to be off by several hundred kg.

 

[pbehn]

Just imagine how good the Spitfire would have been if it hadn't been made?

 

[rochie]

Just imagine how good the Spitfire would have been if it hadn't been made?

Or how much better it would've been with black crosses instead of roundels !

 

[pbehn]

Or how much better it would've been with black crosses instead of roundels !

I was thinking more about turning the engine upside down and taking an angle grinder to any curved surface.

 

[Airframes]

But then Galland wouldn't have asked for a Staffel of Spitfires ........... "Nein, der motor ist now wrong, und you are making der vings too straight !"

 

[rochie]

I was thinking more about turning the engine upside down and taking an angle grinder to any curved surface.

No Black crosses add 15% to all performance specs of WW2 weapon systems

 

[pbehn]

No Black crosses add 15% to all performance specs of WW2 weapon systems

In truth a plane probably suffers a 15% drop in performance when everything it needs is added, almost all of these discussions concern aircraft that were not mass produced.

 

[tomo pauk]

I'm not sure that you've understand the joke. An aircraft XYZ will do, say, 350 mph if it has British roundels or Japanese rising suns, however you need to add 15% on that figure if it has black crosses on itself.

 

[Shortround6]

I'm not suggesting the Luftwaffe strap an R1820 onto a BF-109 airframe, but rather a clean-sheet design. Single row radial engines are easier to build and maintain than V12s. With careful layout and detail design, I estimate that an R1820 powered fighter could meet or exceed Spitfire MK.IX levels of performance on 87 octane gas with roughly BoB level of technology.

Unless you mistyped Spitfire MK.IX there is not a chance on the face of the earth of this happening without large quantities of fairy dust or magic reindeer towing the radial engine fighter.

Please note that a P-36 with a two row radial had 22% more drag than than a P-40 long nose.

An R-1820 using 87 octane fuel in 1940 was lucky to get to 1000hp.
The G series ran at 2200rpm, the G100s could run at 2350rpm and the G-200s could run at 2500rpm.

now just do the math, 1820 cu in times the rpm, divide by 2 (one power stroke every other revolution.) then divided by 1728 to get cubic ft of air per minute.
gives the R-1820 about 1320 cu ft of air per minute (disregarding boost at the moment) compared to the Merlins 1432 cu ft of air per minute. (zero boost) Now 6lbs of boost is about a 40% increase in airflow (very roughly) and 12lbs is 80%. a 1200hp R-1820 used 45in (7.75lbs) for take-off but could only hold that power to a bit over 4000ft.

Now we get back to boost, The later models of the R-1820 were rated on 91 octane or 100 octane fuel, not 87. The British never used 91 octane or perhaps I should say they never bought it or issued specifications for it.
Air cooled engine had trouble using the same boost as liquid cooled engines using the same fuel.

Without a turbo the R-1820 is toast even before it gets to 10,000ft. even with a two speed supercharger and 100 octane fuel it was only good for 1000hp at 14,200ft. which is hundreds of horsepower and thousands of feet to low to compete with a MK IX SPit.

 

[pbehn]

I'm not sure that you've understand the joke. An aircraft XYZ will do, say, 350 mph if it has British roundels or Japanese rising suns, however you need to add 15% on that figure if it has black crosses on itself.

I understand, but in a way it is understandable when you realise they are extrapolating from prototype or experimental results. The reason is obvious, the Spitfire and Mosquito were so damned pretty an ugly hairy assed version must have been quicker.

 

[Milosh]

There was a radial engined Bf109.

 

[Shortround6]

There were two, One with a P & W R-1830 and one with a BMW801.

 

[pbehn]

now just do the math, 1820 cu in times the rpm, divide by 2 (one power stroke every other revolution.) then divided by 1728 to get cubic ft of air per minute.
gives the R-1820 about 1320 cu ft of air per minute (disregarding boost at the moment) compared to the Merlins 1432 cu ft of air per minute. (zero boost) Now 6lbs of boost is about a 40% increase in airflow (very roughly) and 12lbs is 80%. a 1200hp R-1820 used 45in (7.75lbs) for take-off but could only hold that power to a bit over 4000ft.

QUOTE].

S/R I wish you wouldn't say things like "do the math" I am tempted to do it and end up knowing less than before

 

[Shortround6]

Don't worry, I stay away from things like "if a train left Chicago for New York at 40mph and a train left New York for Chicago at the same time doing 60mph.........."

Maybe if I just say arithmetic

 

[KiwiBiggles]

No Black crosses add 15% to all performance specs of WW2 weapon systems

And turn the fuselage into Tardis.

 

[pbehn]

Don't worry, I stay away from things like "if a train left Chicago for New York at 40mph and a train left New York for Chicago at the same time doing 60mph.........."

Maybe if I just say arithmetic

With most things in physics concerning engines and aircraft I can build up a mental picture to understand it, with WW2 aircraft engines that never happens, beyond the basics there are just too many variables for my little head to cope with.

 

[wuzak]

Unless you mistyped Spitfire MK.IX there is not a chance on the face of the earth of this happening without large quantities of fairy dust or magic reindeer towing the radial engine fighter.

Please note that a P-36 with a two row radial had 22% more drag than than a P-40 long nose.

An R-1820 using 87 octane fuel in 1940 was lucky to get to 1000hp.
The G series ran at 2200rpm, the G100s could run at 2350rpm and the G-200s could run at 2500rpm.

now just do the math, 1820 cu in times the rpm, divide by 2 (one power stroke every other revolution.) then divided by 1728 to get cubic ft of air per minute.
gives the R-1820 about 1320 cu ft of air per minute (disregarding boost at the moment) compared to the Merlins 1432 cu ft of air per minute. (zero boost) Now 6lbs of boost is about a 40% increase in airflow (very roughly) and 12lbs is 80%. a 1200hp R-1820 used 45in (7.75lbs) for take-off but could only hold that power to a bit over 4000ft.

Now we get back to boost, The later models of the R-1820 were rated on 91 octane or 100 octane fuel, not 87. The British never used 91 octane or perhaps I should say they never bought it or issued specifications for it.
Air cooled engine had trouble using the same boost as liquid cooled engines using the same fuel.

Without a turbo the R-1820 is toast even before it gets to 10,000ft. even with a two speed supercharger and 100 octane fuel it was only good for 1000hp at 14,200ft. which is hundreds of horsepower and thousands of feet to low to compete with a MK IX SPit.

Some numbers.
Martlet I, Cyclone G205A: 1,200hp @ 4,000ft, 1,000hp @ 14,000ft

http://www.wwiiaircraftperformance.org/f4f/martlet-I-ads.jpg


Spitfire I, Merlin III, +12psi: 1,300hp @ 9,000ft, (1,000hp @ 17,000ft)
+6.25psi: 1,030hp @ 16,000ft.

http://www.spitfireperformance.com/merlin3curve.jpg

 

[InlineRanger]

I'm not sure that Spitfire have had torsionaly stiffer wing that Bf 109, at least not until late 1944/early 45 when Mk.18 emerged, or perhaps until Mk.21 emerged. 109E was rolling at much greater rate until 250 mph indicated speed, the Spitfire taking the slight lead past 320 mph indicated.

While the Spitfire had a thin wing, the leading edge formed an unbroken d-shaped torsion box. You're right that the Spitfire Mk.21 had additional structure added aft of the wing to bring the aileron reversal speed up from 580mph to 850mph. As far as I can tell, the BF-109 doesn't have a closed torsion box any where on its wing. The area forward of the spar is broken by the landing gear well and the area to the rear is broken by the radiator duct. I'm not 100% sure though, so I'd love to be proven wrong!

Bf 109E was much easier to enter a dive and keep the advantage. External ballistics of the MH FFM and MG 17 were close enough, the Spitfire was a bigger aircraft thus easier to spot and hit. Spitfire's (and Hurricane's) armament was far from perfect during the BoB, level of criticysm ranging from mild to harsh.
In order to be outclassed, the 'winner' need to trash the 'looser' by a wide margin. Talk Corsair vs. Zero, or Bf 109 vs. Hurricane. Not the case with Bf 109E vs. BoB Spitfires.

Pireps on the 109E note its heavy elevator controls, making pulling out of a dive difficult.

AFAIK, the BF-109E used three different weapon configurations during the BoB, the most numerous being the E3 w/ 2x MG17 and 2x MG FF firing AP projectiles. The MG17 has a muzzle velocity ~50% higher than the MG FF. I haven't been able to find ballistic coefficients for the 8mm Mauser AP and 20x80mm AP, but I doubt they're too similar. The MG FF round is going to take longer to reach the target and drop more by the time it arrives. The 109E pilot must estimate lead differently and the poor sight line over the nose will make deflection shooting tougher. Don't get me wrong, the .303 was marginally effective, but I think volume and uniformity made the Spitfire pilot's life easier during the BoB.

Well, I guess "outclass" is subjective.

Once again - the choice of engine layout and wepon layout have had no bearing on landing gear geometry; the prototypes for fighter competition were powered by up-right V12 without provision for engine cannon. Might also check out the He 112 and 110.

My point was that the inverted engine, motor cannon and landing gear geometry individually compromised the design. With that said, the engine and armament choice did have an effect on the landing gear. The motor cannon requires the propeller hub to sit further from the crankshaft so the barrel can clear the cylinders. On an inverted engine, this places the propeller shaft lower on the engine, meaning either the engine must be installed higher in the airframe or the landing gear legs made longer. The BF-109 appears to have chosen the latter.

I don't think they would've benefitted at all, their war effort will receive an own goal with that scenario.

I don't understand what you mean.