Spit/109 sea level speed comparisons in 1.08 beta patch

[MusseMus]

Inspired by another post here about possible speed gauge error I made a little test.

I created a mission in FMB, where I let 2 AI planes fly next to each other for some miles. One was a 109E-4 and the other a Spit 1 and they were programmed to go at 300 kph at 500 meters.
I measured the time it took for them to travel 20 km and I checked their speed gaugets (AI on).

Observation 1: The 109E-4 outran the Spit on every try No idea why they did not match speed since I used exactly the same settings on them.

Observation 2:
The airspeed gauge on the 109 red 310 kph, but the calculation gave me 325 kph=a difference of about 5%

The spits gauge showd 170 mph=273 kph, but the calculations gave me 316 kph=a difference of about 15%

I'm aware that I'm comparing IAS and ground speed here, but the difference at 500 meters should not be this big, right?

Compare theese results with Cambers table
Coincidence?

/m

Originally Posted by camber

[Crumpp]

In short I don't see how it proves anything.

Well, that is because you don't understand aircraft performance.

That is ok and you are not alone.

It proves exactly what I said and the math does not lie nor is it bias.

I will see if I can help you. If I can't, oh well, it does not change the physics or the math.

Angle of bank and load factor have a fixed relationship in a steady state turn.

For example, 60 degree of bank will always produce a 2g load factor no matter what the aircraft under consideration.

Turn rate and radius is a function of angle of bank and velocity.

All aircraft at the same angle of bank and velocity will make exactly the same turn. So if a Cessna Corvalis and a Boeing 747 are going 200 knots and banks 60 degrees, they will both make the same rate and radius of turn.

Radius is very velocity dependant.

From an FAA question when getting your commercial certificate.....

An aircraft holds a constant angle of bank and velocity increases. What is the effect on radius?

The correct answer is load factor remains constant and radius increases.

At the same velocity, the aircraft which can sustain the highest angle of bank is achieving the higher load factor and will make a smaller radius as well as higher rate of turn.


So that diagram shows the Spitfire cannot realize a sustained turn performance advantage until it reaches the portion of the envelope the Bf-109 cannot fly in anyway. Then the Bf-109 must reduce its angle of bank in order to match speed and the Spitfire can sustain a higher angle of bank in that portion of the envelope.

If a Spitfire enters a turn fight with a Bf-109, the Bf-109 can force the Spitfire into this low speed realm. The Bf-109 will simply outturn or match any Spitfire that tries to remain at the same speed or maintain velocity.

So both pilots have to make a choice. The Spitfire pilot can choose to hold onto his airspeed and be shot down. The Bf-109 pilot can choose to follow the Spitfire into the low speed realm and be shot down.

Factor in stability and control, these aircraft are even more equal dogfighters. The Bf-109 pilot can precisely attain and hold a target load factor to achive maximum performance.

The Spitfire requires a skilled pilot to precisely achieve and maintain a target load factor in order to achieve maximum performance.

Understand?

[Crumpp]

I believe your bottom line re a faster aircraft always outturning a slower one to be wrong.

An aircraft at Vmax has zero excess power.

So, the slower airplane has zeo excess power at its top level speed while the faster still has excess power to maneuver.

Understand?

[Crumpp]

For example, the ROC reads around 65+ fpm while sitting still on the runway!

Have you sat in the cockpit of many real airplanes?

[IvanK]

Emm we have this chart from RAE



It clearly shows that the Spitfire MK I has better sustained turn performance throughout the speed range than the Bf109E3. It also shows Max sustained G of the Spit as 3G whilst the max sustained G of the BF109E3 is about 2.3G. With the Spit I weighing 6000lbs and the 109E3 weighing 5600lb.

We then have this chart



Which shows the BF109E3 having a better sustained turn performance than the Spifire MKI throughout the speed range. This chart shows (at Take off weight nonetheless) the Spitfire max sustained G of 3.2 g and the BF109E3 max sustained G of 3.25g

Whose chart do you believe RAE or this other thing ?

[Al Schlageter]

Well Ivan I would believe the chart made by a practicing aeronautical engineer over a theoretical aeronautical engineer.

[Robo.]

Originally Posted by Crumpp

All aircraft at the same angle of bank and velocity will make exactly the same turn. So if a Cessna Corvalis and a Boeing 747 are going 200 knots and banks 60 degrees, they will both make the same rate and radius of turn.

Yes this is true. For a graph of a hypothetical situation, but if it was actual dogfight, the Cessna would outturn the 747. I understand what you're saying though.

Originally Posted by Crumpp

So that diagram shows the Spitfire cannot realize a sustained turn performance advantage until it reaches the portion of the envelope the Bf-109 cannot fly in anyway.

Diagram shows something that did not exist in real life and luckily it does not exist in the sim either. Spitfire can realize the turn performance advantage at almost any moment unless the speed difference is largely in favour of the 109 - at which point the 109 pilot won't try to enter a pure turning competition (and that's what we're talking here about) anyway.

Originally Posted by Crumpp

Then the Bf-109 must reduce its angle of bank in order to match speed and the Spitfire can sustain a higher angle of bank in that portion of the envelope.

First pilot to reduce the angle of bank is very likely to lose the (turn)fight. If the 109 pilot gains speed and climbs we haven't got pure turnfight anymore and we can't speak of sustained turn either. Of course, in real virtual dogfights this is exactly what happens and both pilots usually fly yo-yos and the turn is egg-shaped rather than a circle etc. There is much more to it in actual combat. Sustained horizontal turn rate is still very important when it comes to TnB and this is where Spitfire beats the 109. (still depending on the pilots of course).

Originally Posted by Crumpp

If a Spitfire enters a turn fight with a Bf-109, the Bf-109 can force the Spitfire into this low speed realm. The Bf-109 will simply outturn or match any Spitfire that tries to remain at the same speed or maintain velocity.

I suggest you start flying these combat flight sims, while you're hangin around on the forums you might as well want to actually try what you're typing in here. It won't work I am telling you now

Originally Posted by Crumpp

So both pilots have to make a choice. The Spitfire pilot can choose to hold onto his airspeed and be shot down. The Bf-109 pilot can choose to follow the Spitfire into the low speed realm and be shot down.

This is as wrong as it can get mate

Originally Posted by Crumpp

The Bf-109 pilot can precisely attain and hold a target load factor to achive maximum performance.

Any pilot can do that. Of course pilot skill plays a huge role in here, too. There are more tricks in how to outturn your opponent and win the edge. This is where the human factor comes in. But speaking strictly of the machines and the sustained turn potential, Spitfire would be the winner at typical TnB speeds. That's why any sane 109 pilot avoids TnB with a Spitfire.

Originally Posted by Crumpp

The Spitfire requires a skilled pilot to precisely achieve and maintain a target load factor in order to achieve maximum performance.

Actually it's the other way around. Average Spitfire pilot will outturn any average 109 pilot hands down when it comes to sustained turn. It requires exceptional 109 pilot (esp. engine management and stall control, very clean rudder) to outturn a decent Spitfire pilot in a proper turnfight.

Originally Posted by Crumpp

Understand?

I understand that you have no experience with virtual dogfight. Your theoretical knoweledge is useful but you would die in combat if you tried to apply it.

[Crumpp]

Originally Posted by Robo.

Yes this is true. For a graph of a hypothetical situation, but if it was actual dogfight, the Cessna would outturn the 747. I understand what you're saying though.

In actual dogfight, physics does not change.

Diagram shows something that did not exist in real life and luckily it does not exist in the sim either. Spitfire can realize the turn performance advantage at almost any moment unless the speed difference is largely in favour of the 109 - at which point the 109 pilot won't try to enter a pure turning competition (and that's what we're talking here about) anyway.

See Above, the math is the math.

First pilot to reduce the angle of bank is very likely to lose the (turn)fight. If the 109 pilot gains speed and climbs we haven't got pure turnfight anymore and we can't speak of sustained turn either. Of course, in real virtual dogfights this is exactly what happens and both pilots usually fly yo-yos and the turn is egg-shaped rather than a circle etc. There is much more to it in actual combat. Sustained horizontal turn rate is still very important when it comes to TnB and this is where Spitfire beats the 109. (still depending on the pilots of course).

Right, and the Spitfire is outturned at higher velocity because it cannot sustain as high a turn rate at higher speeds.

I suggest you start flying these combat flight sims, while you're hangin around on the forums you might as well want to actually try what you're typing in here. It won't work I am telling you now

This is as wrong as it can get mate

Not an issue and has not effect with what happens in reality. It is hard to overcome the physics of the Bf-109 being lighter with the same power. This is an advantage where performance is thrust limited.


Any pilot can do that. Of course pilot skill plays a huge role in here, too. There are more tricks in how to outturn your opponent and win the edge. This is where the human factor comes in. But speaking strictly of the machines and the sustained turn potential, Spitfire would be the winner at typical TnB speeds. That's why any sane 109 pilot avoids TnB with a Spitfire.

Sure, it depends on the speed though.

Actually it's the other way around. Average Spitfire pilot will outturn any average 109 pilot hands down when it comes to sustained turn. It requires exceptional 109 pilot (esp. engine management and stall control, very clean rudder) to outturn a decent Spitfire pilot in a proper turnfight.

Maybe if they fix the stability and control it will be more realistic. Of course that will not change the speeds performance occurs....

I understand that you have no experience with virtual dogfight. Your theoretical knoweledge is useful but you would die in combat if you tried to apply it.

I admit I have limited knowledge about virtual airplanes. My expertise lies with the real ones.

[bongodriver]

Originally Posted by Crumpp

I admit I have limited knowledge about airplanes. My expertise is lies.

fixed that for ya.

[Robo.]

Originally Posted by Crumpp

I admit I have limited knowledge about virtual airplanes. My expertise lies with the real ones.

Do you dogfight in the real ones? Do you dogfight at least in the virtual ones? Apparently not - that's all I am saying. I appreciate your theoretical knowledge of a/c engineering but you're simply wrong here. Not with the physics, there is nothing to argue about - but everything else you're saying makes no sense from the fighter pilot's point of view.

Originally Posted by Crumpp

In actual dogfight, physics does not change.

Of course not but what you're saying has nothing to do with the ability of the aircraft to turn in a combat situation. You got it right with the best performance velocities - and that's all the turnfight is. The fact that the 109 at say 400km/h can turn better than a Spitfire at say 250km/h is irrelevant. Useful in combat, but not for turnfight. It's called 'turn and burn' where the opponents get the best use of turn rate advantage. In this particular case, Spitfire has got the advantage.

Originally Posted by Crumpp

Not an issue and has not effect with what happens in reality. It is hard to overcome the physics of the Bf-109 being lighter with the same power. This is an advantage where performance is thrust limited.

Lighter with the same power = better climbrate but not necessarily better turnrate in typical combat situations. The Spitfire though could still outturn the 109

If you could perhaps describe how exactly would you outturn a Spitfire Mk.I in a Bf 109E, I am very interested. Everything you are saying is true but you would be dead in a turnfight because you're wrong about what is important in actual combat.