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109 control limeter is too high on low speed


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Its almost impossible to flight with this high limiter control under on low speed.

I can only press full rudder or pull and push the stick on full range under 200km/h after 300km/h the 109 pilot have no possibility to use the stick or rudder on full range and have lost great of control range.

After 400km/h you lost almost all range.... Why 109 have this high limiter.. I cant see anything like that in my Spit?

I dont did the same test with my P51, p47 or FW190D but.... Its will be as is now or its a WIP effect thing that will be tuned soon and it will be implented in another planes.


Edited by greco.bernardi
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  • 4 weeks later...

Bf-109 stick forces are very high compare  to other planes.

You are calming that limit is too high at 300kph any data or proofs for this or just a feeling. 

Second graf fw190 vs bf-109 at high speed, stick forces for Fw190 almost 0.

post-1354-0-12636700-1395327534.jpg


Edited by grafspee

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I have a few questions for those graphics:

 

The first one

What exactly do those values mean? Is it the required pressure to maintain altitude (lower graphs) and to achieve maximum deflection (upper graph) or is it default deflection at that speed? 

 

For example push ~20kg at M0.6, is that for maximum deflection or untrimmed level flight? 

 

Or 2 degrees of pushing at M0.6, what does that mean? 

 

And the second graphic

Seeing the curve going towards 0kg at around 300 kph, that should be very light, no? But at the same time, the second graph never meets it. What is that value, Ph and the Nh? 


Edited by razo+r
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Some scientific data regarding the subject of stick forces:

https://apps.dtic.mil/dtic/tr/fulltext/u2/639028.pdf

"The NACA study measured the forces that could be exerted by a pilot operating a stick with his right hand in many hand positions and with the cockpit tilted in several attitudes. Using as reference values the maximum forces that could be exerted by the weaker of the two pilots who served as subjects, it was found that "the average of the ... push and pull forces that could be exerted in all attitudes with the controls in the neutral positions is 35, 95 and 400 lbs. respectively...for ailerons, elevator and rudder" (17). "

 In the 109 that we have in DCS, the ailerons are not affected by the stick forces but only the elevators. Secondly, it seems that the pilot cannot pull more than a few pounds of force at low speeds which contradicts both the scientific data and real pilots' testimonials. The 109 stick forces must be revised accordingly to have a plane that can be controlled in a realistic manner.

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First one (rough translation, some contain word-to-word translations):

 

Reason: In the investigations and messages of DVL Nr. 1077 from E. Kuhle has reported of the extraordinary deviations from the normal trend of the dynamic pressure handforces  (Staudruck = dynamic pressure?) and the rudderangles of the Fw-190 at medium Mach numbers.

Due to this overturning reason, such deviations especially in regards of loadacceptance, investigations shall be made with help of air measurements, if the Me 109 has similar phenomenas.

 

test execution: With the Me 109 W.NR.26107 3 flights have been made with an S position = 21.2% (15min after start), a tailsetting of +0.75 degrees, p=1.15 ata and n=2300 U/min with v=400, 530 and 610 kph in altitudes between 2000m and 7000m. 

The elevatorcontrol handforce and the rudder angle have been measured with a DVL-measurement-stick and a DVL-rudder-position-scratchwriter (word by word translation).

Va was read from the speedmeter.

 

Because the high values of Va could only be kept at an angled flight path, for simplification of the trial programm the dives have been conducted throughout several altitude steps of thousands of meters with constant  Va and in 7000m and 2000m as well as in 2 altitudes inbetween, the 2 measurement devices were turned on.

 

Result: In contrary to the Fw-190, the measurements showed the pressureforce and elevatorangle of the Me-109 have only a slight dependency on the Mach number until Ma=0.73 (sheet 4 u 5)

 

names and specs of the 109

 

 

Second

 

Discussion of the seperate results:

 

In above mentioned DVL-report from E.Kuhle "Flight measurements of the properties around the transverse axis at high Mach numbers on the Fw-190" the measured ruddermoments and rudderdeflections are noted above (1/qa) (don't know if q or 9). This graphic has the disadvantage, that the questioned area with higher Mach numbers the few measured points are close to each other and thus easily tempt to be drawn as a curve, which in reality is not reasoned. If you draw the curve (Mr/qa)*(1/qa) and (Nh)*(1/qa) of the mentioned DVL-report in the more clean drawing (Auftragung comes close to it) above "qa" (sheet 1-3), it immediately shows due to the lack of measurement points the insecure curve at Mach numbers above 0.6. It is therefore better, the drawing above "1/q", which should show the deviation from the linearity, retrospectively gained from the dependency of the pressure (or pressuredependency).

 

Apart from the art of drawing promoted arbitrariness in the curve, it is due to the lack of center of gravity / mass & balance in this DVL-report that there is room for guesswork, that certain deviations from the normal curve are because of the change of the S-position. For example in the Me-109, due to fuel consumption, the center of gravity can shift up to 6%.

The results of the Me-109 were because the previously mentioned reasons drawed with the indicated dynamic pressure (staudruck) "qa" (Sheet 4).

 

The Handforces increase less than linear with the dynamic pressure, the rudder deflection on the other hand slightly decrease. The Mach number dependency of the handforce and rudder deflection is low. On sheet 5, the 2 values of Va = 530kph & 610 kph besides the values for the Fw-190 at Va = 650kph.

 

The original measurement programm could not be fully finished, because the airplane had to be returned.  But simply because of the existing measurements, one can see that in case of the Me-109, up to a Mach number of 0.73 no extraordinary deviations from the normal force and rudderdeflectiontrend show up. (Same thing show the measurements on the Me-262)

It is important to note, that in the first flights to these trial highly scattered results show up, because the pilot did not pay attention to the slip of the aircraft during the dive, which has a high influence on the elevator handforce.

 

Because the flights were conducted in such a way, that over a big difference in altitude Va remained constant, so is to be considered, if the curvature of the trajectory added a change to the normal acceleration and thus the rudder deflection considerably influenced. The calculations afterwards showed a with decreasing altitude a steeper trajectory, but the with that connected acceleration and rudder deflection is due to the weak  trajectory curvature without importance.

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  • 2 weeks later...

Thank you for posting all these interesting infos. I do believe, that applying a steering forces to flight sim is extremely difficult. As far as I find a Bf-109 K4 being (among MiG-15bis) best module in DCS, i have allways problems with these subject. It's simple true that pulling stick with 40KG force is a difficult task, and... It wasn't a mistake or design failure. It was rather precisely designed way of giving a pilot proper feedback about how high are G-Forces at given airspeed. It was a brilliant way to avoid pilot to pass out as a result of blackout (and I'm quoting here Mark Hanna whom I heard speaking and watched flying Spitfire in Goraszka in 1997 - a world famous pilot, owner of Spitfire and BF109). The forces on the stick are in Bf corelated with G-Forces. 

 

Sooo... It's not a bug it's a feature. One more thing:
 

A forces on stick are very easily regulated by a shape of elevator. Such feature is called "Aerodynamic compensation". Simply by placing a significant part of rudder before elevator axis, one can lower a forces necessary to apply to a stick. like here:
Elevator with simple aerodynamic compensation:
image011.jpg

 

So ... having a correlation of Stick forces and Ma number is a calculated behave, and it's not easy to construct a steering forces to work like these. There's lot of problems like flatter or buffeting that are making it complicated, or impossible. A simple example of such problems (and unfortunately an example of failure in these area) is a Supermarine Spitfire. A pilots were able to surprise themselves by applying too much G-Force. A surprise came from the fact, that steering forces on Spitfire were very low. Later Spitfire become a additional weight on the end of elevator surface to quick solve a problem, but Supermarine never managed to correlate Speed with Steering forces in a way that it would prevent pilots from applying accidentally too much G-Force.

Most US - made Planes were not having these problem, because of hydraulic servo, FW190 was developed in a bit hurry - there was no time to take care of such small problems, so as "Das Bericht" describes - "Steering forces are not correlated with Ma number".

With my best regards
303_Kermit


Edited by 303_Kermit
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US planes didn't have hydraulic servos for their elevators and suffered the same issues. Remember reading the P-51 felt like a truck in elevator forces at high speeds, just like the 109.

 

Most importantly the 109 could be trimmed out of a high speed dive that would doom most other aircraft thanks to its fully trimmable horizontal stab.


Edited by Hummingbird
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On 2/8/2021 at 4:11 PM, Hummingbird said:

US planes didn't have hydraulic servos for their elevators and suffered the same issues. Remember reading the P-51 felt like a truck in elevator forces at high speeds, just like the 109.

 

Most importantly the 109 could be trimmed out of a high speed dive that would doom most other aircraft thanks to its fully trimmable horizontal stab.

 

Every single P-51 manual says that elevator stick forces are relatively light, that excessive pull out is possible especially at high speeds.

At least one US plane during WW2 had hydraulic booster ailerons, this plane was P-38, elevator i dont know any.


Edited by grafspee

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Only minor side Note, US Planes are equipped with Trim Tabs (no Hydraulics,exept from the P-38) small surfaces  in the Rudder deflect in the oposite Position of the Rudder to support and overcome the Forces created from the slipstream.  And the Fw-190 was very well devloped in this regards, it uses sophisticated lever Arms and Bearings to reduce the Rudder Load not to suffer the same Problems as the 109.


 
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On 12/24/2020 at 7:34 PM, greco.bernardi said:

Its almost impossible to flight with this high limiter control under on low speed.

I can only press full rudder or pull and push the stick on full range under 200km/h after 300km/h the 109 pilot have no possibility to use the stick or rudder on full range and have lost great of control range.

After 400km/h you lost almost all range.... Why 109 have this high limiter.. I cant see anything like that in my Spit?

I dont did the same test with my P51, p47 or FW190D but.... Its will be as is now or its a WIP effect thing that will be tuned soon and it will be implented in another planes.

 


Basically we are dragging a old bug for years. The elevator neutral trim is broken.
It seem, that E.D. devs team, mistaken the trimable horizontal stabilicer setting for cruising at stright and LEVEL flight of the Bf-109K4, with other settings for DIVE or CLIMB in a Bf-109G2/R6 (with 20mm cannons gunpods) used in a old wartime soviet trials report.

One of these developer stated that the "real Bf-109" flying at hight speed with the THS (Trimmable Horizontal stabilizer) set at +1.5 degrees, need constant PULLING of the stick, ...but we fly straight and level or PUSHING stick with this THS setting in game. 

Moreover, we have a special setting page in game, for preflight settings of the controls trim tabs plates of the Bf109k4, and this developer stated that elevator tabs plates ajustement "is blocked" in game intenationatelly.
that´s the reason that elevator trim plates do not appear in that special setting page.


image.png




 

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You highlighted wrong tabs for rudder trim, you should circled this tab between those 2 which you highlighted.

RzgdMPJ.png

At current state of things about K-4 it is 100% logical that we are not allowed to trim this plane any more nose heavy, even right now with plane trimmed nose heavy i find hard time in pulling out of fast dives.

I have only charts from G-2 tests showing that stick forces are much higher then stick forces in Fw190, which game represents.

Now we cant ask any of pilot which is flying those things, no one is pulling more then 2G-3G in those planes now.

I just wonder why ED no allow for elevator trim tabs adjustment, and let ppl crush hard in to ground.

I doubt that K-4 would change magically in to 1pound per G spitfire.


Edited by grafspee
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 In conclusion, having the stick forces correlated with Mach number is a very good thing for an aircraft and the high stick forces @ low speeds on the 109 are just WRONG. Currently, the Spit users are 'cheating' by changing the axes (X,Y) saturation and curves to prevent the 'over G', and that should be disabled to prevent this artificial change of the aircraft behavior.

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32 minutes ago, amazingme said:

 In conclusion, having the stick forces correlated with Mach number is a very good thing for an aircraft and the high stick forces @ low speeds on the 109 are just WRONG. Currently, the Spit users are 'cheating' by changing the axes (X,Y) saturation and curves to prevent the 'over G', and that should be disabled to prevent this artificial change of the aircraft behavior.

 

Turning a discussuion on stick forces of the DCS Bf 109K into a attack on the Spitfire community.

 

You really are an insufferable pillock.

 

 

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6 hours ago, grafspee said:

You highlighted wrong tabs for rudder trim, you should circled this tab between those 2 which you highlighted.

RzgdMPJ.png

 

 

That thing that you have marked in yellow is the Flettner tab (a servo-tab) its moving for counterbalance the rudder forces.
That is NOT trim tab plate.

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13 minutes ago, IIIJG52_Otto_ said:

That thing that you have marked in yellow is the Flettner tab (a servo-tab) its moving for counterbalance the rudder forces.
That is NOT trim tab plate.

You are right.

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3 hours ago, amazingme said:

 In conclusion, having the stick forces correlated with Mach number is a very good thing for an aircraft and the high stick forces @ low speeds on the 109 are just WRONG. Currently, the Spit users are 'cheating' by changing the axes (X,Y) saturation and curves to prevent the 'over G', and that should be disabled to prevent this artificial change of the aircraft behavior.

By the way @rel4y explained perfectly the trim tab plates influence in dives and stick force here.
 

Quote

 

 


Edited by IIIJG52_Otto_
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6 hours ago, grafspee said:

At current state of things about K-4 it is 100% logical that we are not allowed to trim this plane any more nose heavy, even right now with plane trimmed nose heavy i find hard time in pulling out of fast dives.

The only thing that you need to do for recover a dive in the current FM, is to move the THS (Trimmable Horizontal Stabilizer) to neutral position, "ZERO" in the gauge. Because the airplane is very tail heavy in this position.. ...a lot of more than the real one Bf-109. 
Moreover, due to we can fly the aircraft almost trimmed, with THS in FULL nose-down position (+2 degrees in the gauge) we have 8 degrees for trimming in tail-hevy direction (minus -6º in the gauge) ..Any resemblance to a real Bf-109 is a pure coincidence, ..but it is the current FM that we got. 😞

By the way, the weight in fuel and MW-50 tanks, did not affecting to that tail heaviest behavior. You can emptiest both tanks in the Mission Editor single flight, and check that the aircraft still flying with tail heavy behabior in ZERO positon.

 


Edited by IIIJG52_Otto_
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4 hours ago, DD_Fenrir said:

 

Turning a discussuion on stick forces of the DCS Bf 109K into a attack on the Spitfire community.

 

You really are an insufferable pillock.

 

 

 First of all, I didn't 'attack' anybody.. I've just explained how the game works.. tell me where in the real plane a pilot can do that.. Secondly, you're the one insulting me every single time you say reply to my comments.

1 hour ago, IIIJG52_Otto_ said:

By the way @rel4y explained perfectly the trim tab plates influence in dives and stick force here.
 

 

 

I very well know about that and if I remember correctly, he even got banned for bringing up the subject. The subject here is 109 control limeter is too high on low speed

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9 minutes ago, amazingme said:

 First of all, I didn't 'attack' anybody..

 

Bullshit - you called anyone who adjusts their curves in the DCS Spitfire a cheat. YOU LITERALLY SPELT THAT OUT ABOVE. HOW IS THAT NOT AN ATTACK?

 

If you had even the faintest idea of what you were going on about you might have a leg to stand on, but time and again, and as so recently displayed by previous outburst you prove nothing but your biblical ignorance.

 

I end up insulting you because time and again reasoned rational discussion fails to get through and I'm sick and tired of dealing with your stubborn ignorant ass.

 

18 minutes ago, amazingme said:

 I very well know about that and if I remember correctly, he even got banned for bringing up the subject.

 

More inflammatory Bullshit. He's here and been posting regularly. A pretty feeble attempt at at pot stirring, I must say, given the ease at which the veracity of your claim is dispelled.

 

21 minutes ago, amazingme said:

The subject here is 109 control limeter is too high on low speed

 

WoW!

 

Trying to adopt a veneer of respectability by calling for On Topic after taking your own toxic little tangent to go after the DCS Spitfire community? That's a level of hypocrisy that is just astounding! What a performance!

 

You are a poisonous, deceitful little weasel. It's enough to make me hope the Bf 109 never gets fixed just to provide you an endless source of frustration to the end of your days.

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16 minutes ago, DD_Fenrir said:

 

Bullshit - you called anyone who adjusts their curves in the DCS Spitfire a cheat. YOU LITERALLY SPELT THAT OUT ABOVE. HOW IS THAT NOT AN ATTACK?

 

If you had even the faintest idea of what you were going on about you might have a leg to stand on, but time and again, and as so recently displayed by previous outburst you prove nothing but your biblical ignorance.

 

I end up insulting you because time and again reasoned rational discussion fails to get through and I'm sick and tired of dealing with your stubborn ignorant ass.

 

 

More inflammatory Bullshit. He's here and been posting regularly. A pretty feeble attempt at at pot stirring, I must say, given the ease at which the veracity of your claim is dispelled.

 

 

WoW!

 

Trying to adopt a veneer of respectability by calling for On Topic after taking your own toxic little tangent to go after the DCS Spitfire community? That's a level of hypocrisy that is just astounding! What a performance!

 

You are a poisonous, deceitful little weasel. It's enough to make me hope the Bf 109 never gets fixed just to provide you an endless source of frustration to the end of your days.

Dude.. you have serious issues.. go seek help. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4108844/

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For those new to the discussion/issue of 109 elevator stick forces and control:

 

1. At this time there is no diagrammed stick force against airspeed chart currently known for the Bf 109K-4.

2. Data pertaining to the Bf 109G was used, from both German and Soviet period tests.*

3. There have been arguments that the elevator control system changed in the 'K', the claims were that this allows the pilot greater mechanical advantage but so far what few docs have surfaced have been reviewed by the lead FM programmer and after review he has stated that what changes there are cannot have the claimed effect.

4. ED have allowed for the virtual pilot to apply two-hands when displacing the virtual stick at these higher stick force regions. There is debate as to whether this is effective enough.

 

Ultimately it's down to EDs lead FM programmer, Yo-Yo, with his wealth of experience, aerodynamic expertise and understanding of the DCS physics engine to decide what data to use/or extrapolate from; assume that he knows more than you. 

 

If in doubt search the DCS: Bf 109K-4 sub-forum for the evidence thus far presented. You will not have far to look.

 

Unless you are able to provide unequivocal, substantive evidence that something is amiss, no amount of 'feelings', out of context anecdotes or suppositions will get you particularly far in getting anything changed.

 

*the G-6 and 'K-4' are so close in tailplane-wing coupling, wing shape and elevator profile that it is not only logical but necessary at this tage to use some B 109G-6 data in the calculation of the FM.


Edited by DD_Fenrir
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