Spit/109 sea level speed comparisons in 1.08 beta patch

[Crumpp]

I already know you're completely wrong with your 'combat speed default trim setting' statement

In otherwords, forget any facts....

You are going to stick to your immature and emotional reaction.


Well, let's see how it pans out.

You can look in the Bf-109E3 Flugzeug Handbuch and see that the engine out instructions call for the pilot to pitch for 200kph IAS. This is best glide speed and corresponds to L/Dmax.

If our curves are correct, this will be the botton of the thrust required curve and tangent of the power required curve.

First the Thrust and Power Required curves:



200kph = 124mph +10 mph PEC = 134mph CAS * .869 = 117KCAS = 117KEAS at sea level.

Yep, best glide aligns perfectly with our curves so we know the curves are correct.

Using the curves, it is easy to find the other cruise speeds.

Maximum endurance will be at the point of minimum power required. Carson's speed is a modern innovation and is the best balance of fuel consumption and speed.

The trim speed of 400kph IAS does not align with any cruise point on the curves. That means the speed was chosen for a different reason.

Now it we look at the rate of turn, or how fast an airplane can bring the guns on target, we see that 206KEAS is a point the Bf-109E3 maintains a healthy rate of turn advantage and can sustain better maneuvering performance.



So, if it was not intentional, it certainly was a very fortunate turn of fate that the Germans choose 400kph to set the trim for the Bf-109E3.

[Crumpp]

how exactly would a 400kph sustained turn in a Bf 109E be useful in actual turnfight vs. a Spitfire Mk.I?

Robo,

This is the key performance parameter for a fighter. It gives the aircraft which can sustain a higher load factor at a higher velocity the initiative in a dogfight.

This characteristic allows the Bf-109E3 to force the Spitfire to a lower airspeed in order to survive the fight.

The outcome of any dogfight is not predetermined. There are too many "what if's" and pilot skills are the determining factor.

What it tells Spitfire pilots is if you enter a sustained turn fight at high speed, the Bf-109 will win if you don't slow your speed down to the point you have a better sustained turn rate.

What it tells the Bf-109 pilot is you can maneuver against the Spitfire, just don't drop your IAS below 400 kph. If he breaks off and zooms at the point the Spitfire begins to out turn him, the Bf-109 will be above his opponent, out of reach, and able to engage/disengage at will.

400 kph is not a difficult point for the Bf-109 to maintain especially given the stability of the design. It is the trim speed and given the correct amount of power, where the airplane wants to be....

[Robo.]

Originally Posted by Crumpp

Robo,

This is the key performance parameter for a fighter. It gives the aircraft which can sustain a higher load factor at a higher velocity the initiative in a dogfight.

This characteristic allows the Bf-109E3 to force the Spitfire to a lower airspeed in order to survive the fight.

The outcome of any dogfight is not predetermined. There are too many "what if's" and pilot skills are the determining factor.

What it tells Spitfire pilots is if you enter a sustained turn fight at high speed, the Bf-109 will win if you don't slow your speed down to the point you have a better sustained turn rate.

Yes, I agree, you said that already before, and this is very well known to most virtual pilot on this forums. You're not saying anything new here. Yes, the 109 turns better at higher speeds, Spitfire wins at lower speeds. What I was trying to explain before was that in a TnB fight, it's usually lower speeds that matter and decide the fight.

There is absolutely nothing wrong with what you're saying, it just doesn't make sense in regards to actual combat. If you keep the 109 in 400kph sustained turn, the Spitfire will be able to shoot at you for long enough to kill you, even being slower.

Originally Posted by Crumpp

What it tells the Bf-109 pilot is you can maneuver against the Spitfire, just don't drop your IAS below 400 kph. If he breaks off and zooms at the point the Spitfire begins to out turn him, the Bf-109 will be above his opponent, out of reach, and able to engage/disengage at will.

If he breaks off and zooms we don't talk about sustained turn competition anymore. Everybody is well aware of 109s BnZ characteristics (if he extends vertically). Again, you're not saying anything new. It's the TnB that matter here. Pure TnB rarely happened because it would be a suicide for the 109 pilot.

Originally Posted by Crumpp

400 kph is not a difficult point for the Bf-109 to maintain especially given the stability of the design. It is the trim speed and given the correct amount of power, where the airplane wants to be....

What you're saying with this whole post of yours is basically:

109 can win a turnfight against the Spitfire as long as it won't turn with it

Spitfire has had better sustained turn rate than 109 and it was generally a silly idea to turn with it. This is the case in the sim as well and all other sims.

[Crumpp]

109 can win a turnfight against the Spitfire

Yes, that is correct.

If he breaks off and zooms we don't talk about sustained turn competition anymore.

Sure we are...

The Spitfire has lost and the Bf-109 has used its sustained turn performance to gain advantage and win the dogfight.

it just doesn't make sense in regards to actual combat.

That is because a computer game is not representing reality in this case.....

There is a very good engineering reason designers have strived for speed as the number one performance parameter for a fighter.

[Osprey]

I'd have hated to have been in your classes (not that I was ever a chicken feeder) because you'd have constantly put the class off with your maniacal theories.

I loved this bit

Originally Posted by Crumpp

There is a very good engineering reason designers have strived for speed as the number one performance parameter for a fighter.

Total misunderstanding of air combat or brilliant trolling?

[Robo.]

Originally Posted by Crumpp

Yes, that is correct.

When they unban you, please stop cutting my quotes like that, I do not appreciate that. It seems you have very selective approach and you only choose to take the bits and bobs that suit you. Please stop arguing at least.

[Kurfürst]

Originally Posted by JtD

I agree it looks simplistic, but technically it is sound and I see no reason it not being an original document. No reason for it being one either, but I will accept it on face value as I see no reason to mistrust Mr.Williams on this issue. If you have more than a gut feeling, I'm willing to re-evaluate my opinion.

Its a gut feeling of course - I wasn't there when it was drawn (thank God for that!). To me it just seems that, given that the original was drawn with pen AND was labeled, compared to the rough approximation visibile on the pencil drawn +12 and +16(?!) lines, the latter lines were probably made by some aircraft enthusiast well after the war. The lines/figures look more or less a reasonable guesswork, but I very much doubt it has anything to do with any test establishment.

Originally Posted by Robo.

Yes, I agree, you said that already before, and this is very well known to most virtual pilot on this forums. You're not saying anything new here. Yes, the 109 turns better at higher speeds, Spitfire wins at lower speeds. What I was trying to explain before was that in a TnB fight, it's usually lower speeds that matter and decide the fight.

There is absolutely nothing wrong with what you're saying, it just doesn't make sense in regards to actual combat. If you keep the 109 in 400kph sustained turn, the Spitfire will be able to shoot at you for long enough to kill you, even being slower.

IMHO the real question is how much time to Spit has to shoot at you? Because if the Spit turns at around its peak sustained turn rate - at about 250 kph? 300 max? - its going to be a good deal slower than the 109; maybe slow enough to fall so behind that it will be out of realistic guns range? You cant shoot what is not in range, even if your nose points towards it..

Moreover if say both aircraft start at 400 + kph, the 109 maintains it while the Spit bleeds it off to get a snapshop, all the 109 has to do is to level out with a very significant E advantage, and if the pilot is good at Energy fight, its all cat-and-mouse from there on.

Generally it seems to me a good idea to keep the speed over 400 km/h in a 109. If the Spit tries to follow you in sustained 400 kph turn, or if he slows down to try to get you, he seems to be ... to have gotten into a bad position. Especially in a multi plane enviroment.. you can shoot what is slow, you cant shoot what is fast.

[bongodriver]

Originally Posted by Kurfürst

IMHO the real question is how much time to Spit has to shoot at you? Because if the Spit turns at around its peak sustained turn rate - at about 250 kph? 300 max? - its going to be a good deal slower than the 109; maybe slow enough to fall so behind that it will be out of realistic guns range? You cant shoot what is not in range, even if your nose points towards it..

Moreover if say both aircraft start at 400 + kph, the 109 maintains it while the Spit bleeds it off to get a snapshop, all the 109 has to do is to level out with a very significant E advantage, and if the pilot is good at Energy fight, its all cat-and-mouse from there on.

Generally it seems to me a good idea to keep the speed over 400 km/h in a 109. If the Spit tries to follow you in sustained 400 kph turn, or if he slows down to try to get you, he seems to be ... to have gotten into a bad position. Especially in a multi plane enviroment.. you can shoot what is slow, you cant shoot what is fast.

But aren't you missing the point completely......you are not describing a turning engagement, the whole issue here is that if the 109 tried to engage in a 'turning' fight with a Spit it 'will' loose, there has never been any disagreement that the 109 had better speed to maintain an overall tactical advantage, the 109 could choose when to engage but the Spitfire was more than capable of evading, if you felt frustrated by that as a 109 driver and decided to try for a propper knife-fight with a Spit you were likely to lose, the 109's best tactic was to run in quick when an opportunity presents itself and run away quicker once the job is done.

[Kurfürst]

Originally Posted by bongodriver

But aren't you missing the point completely......you are not describing a turning engagement, the whole issue here is that if the 109 tried to engage in a 'turning' fight with a Spit it 'will' loose, there has never been any disagreement that the 109 had better speed to maintain an overall tactical advantage, the 109 could choose when to engage but the Spitfire was more than capable of evading, if you felt frustrated by that as a 109 driver and decided to try for a propper knife-fight with a Spit you were likely to lose, the 109's best tactic was to run in quick when an opportunity presents itself and run away quicker once the job is done.

I don't think I have missed anything, but it depends how you define a turn fight. And I am not meaning a 'propper knife-fight' at usually some low speed like 2-300 kph.

What I mean that if
- both the (+6) Spit and the 109E try a sustained turn contest
- near ground level (where the 109 has more power and is faster),
- and both are at or above about 400 kph and try to sustain that,

the Spit WILL loose that turn contest. The Hurricane even more so. As Jtd noted, its simply too hard to overcome some 30(+) km/h speed advantage, and the fact that parasitic drag will be dominant. The general advise is though (apart from don't turn with the Spit at low speeds) is that the faster the 109 turns, the better it is for its pilot.

The other comparisons (one plane flies sustained, the other unsustained, level outs and climbs etc.) I do not adress here. These tactics are essentially combinations of the best peformance envelope against the opponent's worst.

[Robo.]

Originally Posted by Kurfürst

I don't think I have missed anything, but it depends how you define a turn fight. And I am not meaning a 'propper knife-fight' at usually some low speed like 2-300 kph.

What I mean that if
- both the (+6) Spit and the 109E try a sustained turn contest
- near ground level (where the 109 has more power and is faster),
- and both are at or above about 400 kph and try to sustain that,

the Spit WILL loose that turn contest. The Hurricane even more so. As Jtd noted, its simply too hard to overcome some 30(+) km/h speed advantage, and the fact that parasitic drag will be dominant. The general advise is though (apart from don't turn with the Spit at low speeds) is that the faster the 109 turns, the better it is for its pilot.

The other comparisons (one plane flies sustained, the other unsustained, level outs and climbs etc.) I do not adress here. These tactics are essentially combinations of the best peformance envelope against the opponent's worst.

I agree in general except for the fact (major flow I would say) that the Emil will slow down rather fast in this sustained horizontal turn. Spitfire will win in RL situation described by you, because the pilot would obviously not try to sustain these 400kph, he will try to bear his guns on the 109 and will do so rather soon. No matter what you do in a 109, if you chose to remain horizontal, the only way of evading the Spitfire would be flying straight. And flying straight is not sustained turn. See?