So noted: screeds of data all showing the terrible inferiority of the Spitfire, and all stemming from one or two reports.

Agreed! 100 octane is giving a Spit roughly equal speed at low level, even greater speed at low-medium altitudes, which governs most of the high speed turning stuff. Apart from that, without 100 octane the Spit is a bit of trouble against the 109E at higher speeds, since the latter is faster at low altitudes, and in the end its speed that govers most of the high speed turning stuff (since parasitic drag is much more dominant there). Its simply how the turning formulae works, something that some of spit fanatics simply do not want to accept.

Higher altitudes would be interesting btw. The Spit has a more power there (save for the 109E/N) and the two aircraft about the same speed. The Spit has less wingloading, the 109 has higher AR - thus the main factors governing turning are going both ways.. my guess would be a slight Spit advantage there though (save again for the 109E/N).

Bottomline, it doesn't matter how good the plane can turn, if the pilot can't fly it right through the edge. 1-2 seconds can be generally made up by good piloting skills, both ways. ;)

When you calculate out the performance, it is easy to see why Mtt defaulted the trim to 400kph.

That is a very good speed to dogfight the airplane.

http://imageshack.us/a/img542/1949/s...bf109e3sus.jpg

http://imageshack.us/a/img840/8112/rateofturn.jpg

LOL, you do know I was on the FM team for Warbirds at the time. The first FM done was the Spitfire Mk I and Bf-109E series.

When you combined the performance with the flying qualities, these two airplanes are the most evenly matched close quarter dogfighter that existed, IMHO.

Doghfight at 400kph in 1940. Very good :grin:

How exactly would you outturn a Spitfire in a combat again?

Why do you think it would be so difficult to dogfight at 400 kph in an airplane?

Have you flown many airplanes?

Do you know how easy it is to hold a design speed?

First of all, 400kph is within the power stable region of the Bf-109's curves.

What does that mean? It requires ~350 hp to go from the stall point of 82 Knots to 215 Knots (400kph). That is a change of 133 Knots.

We are in a region that small power changes make for large changes in speed.

Compare that with the power required to go from 400 kph to Vmax in the Bf-109E3 is another ~545 hp to increase speed ~54 Knots.

http://imageshack.us/a/img545/7629/p...gionbf109e.jpg



How long will this take?

That too is easy to find out with some applied physics.


Acceleration = (Change in Velocity) divided by (Change in Time)

The average acceleration of the Bf-109E3 from 82 KEAS to 215 KEAS is ~9.6 fps^2.

We have to use the same units so our KEAS is converted to feet per second.

Rearranging our formula to solve for time:

Change in Time = Change in Velocity / Acceleration

delta t = (363fps - 138.4fps) / 9.6 fps^2

Feet cancel out as well as one of the second leaving us with the unit of seconds....

Change in Time = 23.3 seconds

Twenty three seconds from the stall point to the 215 Knots for the Bf-109E3.

Same conditions for the Spitfire:

Going from 82KEAS to 215KEAS, the Spitfire has an average acceleration of 8.4 fps.

delta t = (363fps - 138.4fps) / 8.4 fps^2

Change in time = 27 seconds

Now going from the stall point of 67 KEAS in the Spitfire, we see an average acceleration rate of 9.96 fps. This is because the Spitfire has more excess thrust at low velocity.

Considering that it would be a very stupid Bf-109E3 pilot to be slow flight in the vicinity of a Spitfire, the Bf-109E3 can maneuver quite well and dogfight the Spitfire.

The Bf-109 is pretty safe it if stays in its envelope and does not try to fly were it cannot.

[QUOTE=Crumpp;463075]It does turn better. Look at the calculations I posted.

It just does not do it under all conditions or speeds. That is important, Glider.

If the two airplanes were to have a turning battle to the stall point, the Bf-109E-3 would loose.

Here is the acceleration rates of the two aircraft. The Bf-109E-3 out accelerates the Spitfire Mk I due to its being lighter with more excess thrust.

http://imageshack.us/a/img338/6370/s...09eacelera.jpg

I am sorry but this is rubbish.
a) You are using the wrong power settings for a Spit
b) The 109 controls lock at higher speeds far more so than the spit
c) The German test establishments let alone the pilots in combat would have identified that the 109 turned better at high speed and would have given instructions to their pilots similar to those given to Typhoon, Tempest and USAAF fighters. These essentially went 'Dont enter a slow turning fight with an Me109, keep your energy up and you will have him' Substitute Spitfire for 109 and you would have the german instructions. These were never given.

At 12 lb thrust the Spit produces 1300 hp which puts the power to weight ratio firmly in favour of the Spitfire from which a lot of performance calcs are decided. Without this calculation the charts you posted are of little value.
400 Km is about 250 mph which is not fast.

The Me109E is a tough customer no question and in the overall view there is nothing between them

LOL...

According to the Merlin III power curve, I actually being generous. RAM power for the Merlin III is only about 850 bhp.

weight 6050 lbs
Power 990 bhp
Level speed 247
Propeller efficiency 0.85
Wing area 242
wing efficiency 0.85
Dynamic pressure 206.8101695
Aspect Ratio 5.6
Mass 187.8881988

http://imageshack.us/a/img542/1949/s...09e3sus.th.jpg

Why do you think the trim on the Bf-109 is set to 400 kph IAS???

You do understand they can trim the aircraft for whatever speed they desired?? Having a fixed trim condition is a great way to set the combat speed for your airforce.