Il2 warbirds FM

[TRIAS]

Hello everyone, I was playing flight sims since pretty much F-19 up until now with some on and off periods. I did buy BOS during development and didn't buy BOM due to

my big concerns regarding FM in it. It is hard to put a finger on it but I will try to anyway. 

  I was having a lot of discussions on russian side of the forum regarding FM issues that at the time and still are not looked at, but was brushed off 

by die-hard_no_matter_what_fans so I stopped discussing it one year ago due to that I was unable to persuade developers in my view so here is my shot at it here.

   I looked at 3 sims: CLOD, DCS, IL2BOS/BOM for WW2 birds. Glaring issue to me was that both in CLOD and DCS planes feel as real heavy birds while in IL2BOS

they feel like sport planes on the show. For instance lets look at scissors manoeuvre. For those who doesn't know how to execute those correctly here is a brief overview:

You look at your opponent who is on your 6 and if your plane has a better (faster roll) then you bank to one side at 80-90", your opponent will follow, so as soon as he

reached 90' bank (which would be a bit later then you for obvious reasons) you begin banking to the opposite side.Opponent might have some firing solutions on you while you

pass in front of him, but if you are not doing scissors in one plane then you have a big chance that he would go in front sooner or later (remember? he has slower roll rate). 

In Il2BOS if enemy is on your 6, scissors don't work, planes don't fall TROUGH THE AIR - AS THOUGH THEY ARE VERY LIGHT, so they would stabilize in theeir new trajectory

too readily. Please look at the video of Bf109 below, at min 3:48 bf109 that is behind turns its nose paralles to the one from where it is being filmed from (not like in IL2BOS where he would be

pointing its nose a bit lower - AT YOU and WITHOUT FALLING TROUGH THE AIR would already be hosing you with led). So from 3:48  that bf109 "looks to horizon"  but 

FALLS  BELOW and STOPS FALLING only at around min 3:52) In IL2 BOS planes don't fall through the air as they do in reality so staying on 6 is SUPER EASY and everyone feels as

an ACE. 

I would like those who want to express their opinion regarding this issue (if you think it is) to stay on subject .

Thank you, TRIAS. 

 

[SYN_Haashashin]

Moved to the FM subforum. All discussions regarding this topic should be taken here.

[Turban]

Well, have you tried russian planes?

Try a 109 F4, then try a Mig3 .The Mig 3 is heavy.  The F4 feels like it's levitating. Even lighter feeling than I16.

BUT  how do we see what is wrong excatly? That's the hard part.

 

I have had a "problem" with the "weightlessness" of the 109 for a while.  But to prove it, what do I do ? what do I look at ? What do I compare it to ?

 

The "problem" I have with the 109 is twofold. It stays in the air too well at low speed. You can go vertical, then do a flip, while keeping almost total control, with very minimal altitude loss.

 

That weightlessness helps a lot in fights.

It really is as if the 109 weighted nothing. A leaf with an engine.

 

Then it also rolls way too fast at high speed. But I think that has been discussed and I think (? not sure) the devs might look into it ?

 

 

Anyway, I agree with you, but how do you prove it ?? That's the problem.

Edited April 1, 2016 by Turban

[Alkyan]

This is ridiculous. If there is something easy to compute in a physical engine its the effect of gravity. Just add in your equation computing the movement a force directed to the ground with a norm of m.g (mass multiplicated by 9.18).

 

Subtility in fm comes more from how to model the lift.

 

And the 109 is basically a leaf with a huge engine. Someone once noticed that the power divide by the mass of the 109 is higher than a extra 300. I'll check once home

[t4trouble]

I think the issue is not a fm problem but the netcode.When I go defensive and some 1 is on my 6, what i see and what happens are two totally different things.I've seen their 

 

tracers fall behind my tail which looked correct from my point of view but all of a sudden I'm mortally damaged.

[TRIAS]

PLEASE, stay on topic.

1. This 109 video is just an example, the fact (allegedly) that planes don't fall through not enough is THE SUBJECT of this topic.

 Main idea of my essay is:

 1.  At 3:43 bf109 starts descending towards filming AC

 2.  At 3:48 bf109's fuselage is already parallel to ground

 3.  It takes almost 3-4 sec. for bf109 to stop "falling through air" though its fuselage is parallel to ground

 4. Idea is the same  for any AC (Russian, German or Italian) - planes in IL2 change direction to where they fly

     without  "falling trough the air" -sorry there might be a different (better) definition for it ).

Another words that bf109 pilot anticipated that airplane will not fly parallel to filming aircraft, so he leveled his plane 3 seconds

earlier (put fuselage of his plane in parallel to ground attitude) knowing that it will stop falling (will start ACTUALLY FLYING

in HORIZONTAL PLANE) only 3 sec. later.

 

TRIAS.  

[LukeFF]

Trias, you are wasting your time trying to make a flight model complaint based on a YouTube video.

[TRIAS]

LukeFF, I, personally feel it is IL2BOS/BOM developers who should be interested in this info, which doesn't seem the case from my last year experience with them ( on Russian forum). CLOD is a lookup table based FM (which nonarguably inferior to IL2BOS FM)but they  nailed this  issue pretty good. DCS have it done very well too. It is IL2BOS developers who either don't understand it (hardly believable) or don't want this issue to be known (As it will force them to look/change ALL planes FMs). When I speak to fans of IL2BOS while flying online they

have no idea what I mean, I have a feeling that most of ppl are War Thunder converts who don't really care. I think this issue is changing the picture of aerial battle in a huge way, like scissors are USELESS in flight simulator, isn't it a good argument for developers to look into why. I am showing on real example (video footage) that there is indeed something that can be looked into.

Last year they didn't, maybe now they will.

That is unless they are happy with audience that they already have.

TRIAS.

[II./JG77_Manu*]

Trias, you are wasting your time trying to make a flight model complaint based on a YouTube video.

What's wrong with a Youtube video?

[TRIAS]

        Anyone can check and repeat what was done in the video and prove me wrong. If you start descending like bf109 does (3:43) in video and level your aircraft (3:48) just above filming AC (10 meters higher) (in that case you can film for  instance from back position in Ju87 as a stable filming platform) and see if bf109 would keep falling "through air" (despite its fuselage being level to ground) like it does in a video footage (till 3:52).            You will see that there is no way bf109 (ingame)  would do the same what it does in video footage. It is so obvious that there is no need to prove anything it is right there staring at anyone willing to try, then come back and tell me IL2 BOS does the same. What is better way to prove me wrong?

 

TRIAS.

Edited April 2, 2016 by TRIAS

[LukeFF]

What's wrong with a Youtube video?

 

It's not really a valid source for making a flight model claim. 

[TRIAS]

I make no claim, I offer you to repeat what real life footage does, if you can't - then something is wrong, and that WRONG is not a life footage.     

Cliffs of Dover (CLOD) has it. DCS has it too. IL2BOS/BOM doesn't. I think it is a main reason why planes feel light. Only hobby toy-planes, sport planes, paper ones change direction easily - THEY ARE LIGHT, war birds don't. It would be really nice to hear what real pilots think about it. As soon as you bank your AC (in scissors) to opposite direction,  following you enemy does it as fast as you rendering that tactic (as many others) useless.  

I am NOT arguing about speeds, rolls or other plane flight parameters I am pointing to MAJOR flaw of this game PLANES DON"T SINK through air and video above shows it CLEARLY.

Another example is - LANDING. In DCS and CLOD there is no cowboy style landings, you have to STABILIZE your DESCENT (SINK)  rate prior to landing. In IL2 BOS I can oscillate above airfield with questionable frequency and plane changes ascend/descend the second I move the stick up or down and that is at 10-20 km/h higher then stall speed. I can go on and on.

 

P.S. Amount of interest to this thread is a tell tale as to what audience this Simulator caters to. That in itself might be the main reason why developers don't change anything. It is probably not cost effective to cater to hardcore (few) pilots,

which is understandable.

 

TRIAS. 

[II./JG77_Manu*]

It's not really a valid source for making a flight model claim. 

Showing a video of behavior from a real aircraft is actually the most valid source there is - it's reality, in contrary to often manipulated "historical data"

[BlackBadger]

I'm with OP on this one. Trying out the G2 and F4 they feel twitchy, waving around terribly at 300kmh. Rudder is also just a slower version of the aileron. 

 

Also there was a video posted by the dev's as evidence to support the validity on the fm. The video featured a yak (52 i think?) doing maneuvers. In the video, the guy goes into hammerhead and recovers and stabilizes the plane in a split second. Try that in game.... not possible due to wobble. 

 

Even the E-7 which is by far the best FM in the 109 family here, still can't recover in that fashion. 

[Turban]

I'm with OP on this one. Trying out the G2 and F4 they feel twitchy, waving around terribly at 300kmh. Rudder is also just a slower version of the aileron. 

 

Also there was a video posted by the dev's as evidence to support the validity on the fm. The video featured a yak (52 i think?) doing maneuvers. In the video, the guy goes into hammerhead and recovers and stabilizes the plane in a split second. Try that in game.... not possible due to wobble. 

 

Even the E-7 which is by far the best FM in the 109 family here, still can't recover in that fashion. 

 

It's a Yak 50 in the video. Yak 50 is a great little plane that is built solely for aerobatic purposes. Can't really compare it to a full size WWII fighter when it comes to the "wobblin" 

 

The 109 is one of the most stable aircraft in the game, despite being very maneuverable (usually maneuverable means unstable).  I'm not sure I see what problem you have with it. Do you have a video maybe?

Edited July 2, 2016 by Turban

[6./ZG26_5tuka]

I'm with OP on this one. Trying out the G2 and F4 they feel twitchy, waving around terribly at 300kmh. Rudder is also just a slower version of the aileron.

Yaw induced roll is indeed borked and will be looked at by devs (as per DD120), so it's more or less an acknoledged issue.

Also there was a video posted by the dev's as evidence to support the validity on the fm. The video featured a yak (52 i think?) doing maneuvers. In the video, the guy goes into hammerhead and recovers and stabilizes the plane in a split second. Try that in game.... not possible due to wobble.

That's because the Yak52 is a lighter aircraft with large controll surfaces. Although a lot close to a WW2 fighter than a lot civil aviation aircraft you can't expect it to behave the same way a 3-4t fighter would.

Even the E-7 which is by far the best FM in the 109 family here, still can't recover in that fashion. 

The Emil seem fine to me. It's a nice and stable platform and you can sideslip with it beautyfull unlike the other 109s. Some of the "wobble" complaints may derive from messed up joystcik settings, bad fuel balance or setting up turbulences in weather options.

[BlackBadger]

E-7 as said is the best FM out of the 109's so it doesn't wobble as terribly. But I was surprised I still couldn't recover a stall hammerhead more effectively. I'll need to to a video so you can see what I'm describing, but all I got for now is these:

 

https://youtu.be/wZ_bCT6IC0A?t=23

 

https://youtu.be/5GdzEeaqVZ4?t=34

 

https://youtu.be/OUKu3M9kqv0?t=13

 

Yes they are all different, more modern planes etc. But recovery is gentle in all of them, this is not possible in G2 and F4 and not even in the E7 (I'll have to do a video). What I'm missing is a feeling that I'm in control of the plane. When you attempt a stall hammerhead in G2 or F4 it just wobbles about.  Maybe it's the rudder? Maybe when that's fixed it will improve, who knows. 

[216th_Lucas_From_Hell]

Do share a track, it will be interesting to compare. From my experience one can recover very smoothly from a hammerhead in this game, but besides fuel and etc. the biggest opponent of a smooth recovery is strong torque. I tested it today, in the Bf-109E with the needle at about 1.1 Ata things went pretty smooth without much issue, but for comparison if I try to do that in the La-5 at 2.300 RPM and MP at 10.5 the aircraft starts rolling around the engine and drops into an awkward spin.

[Guest deleted@50488]

Will try it latter today - hammerhead in the La-5 - and report back.

 

From RL I am accustomed to start it with considerable speed while still climbing, because in the glider there is no propwash. The advantage is that there's also no engine / prop torque, but we ereally have to know when to start pushing the rudder in order not to end in an unwanted tailslide...

[JG13_opcode]

Hello everyone, I was playing flight sims since pretty much F-19 up until now with some on and off periods. I did buy BOS during development and didn't buy BOM due to

my big concerns regarding FM in it. It is hard to put a finger on it but I will try to anyway. 

  I was having a lot of discussions on russian side of the forum regarding FM issues that at the time and still are not looked at, but was brushed off 

by die-hard_no_matter_what_fans so I stopped discussing it one year ago due to that I was unable to persuade developers in my view so here is my shot at it here.

   I looked at 3 sims: CLOD, DCS, IL2BOS/BOM for WW2 birds. Glaring issue to me was that both in CLOD and DCS planes feel as real heavy birds while in IL2BOS

they feel like sport planes on the show. For instance lets look at scissors manoeuvre. For those who doesn't know how to execute those correctly here is a brief overview:

You look at your opponent who is on your 6 and if your plane has a better (faster roll) then you bank to one side at 80-90", your opponent will follow, so as soon as he

reached 90' bank (which would be a bit later then you for obvious reasons) you begin banking to the opposite side.Opponent might have some firing solutions on you while you

pass in front of him, but if you are not doing scissors in one plane then you have a big chance that he would go in front sooner or later (remember? he has slower roll rate). 

In Il2BOS if enemy is on your 6, scissors don't work, planes don't fall TROUGH THE AIR - AS THOUGH THEY ARE VERY LIGHT, so they would stabilize in theeir new trajectory

too readily. Please look at the video of Bf109 below, at min 3:48 bf109 that is behind turns its nose paralles to the one from where it is being filmed from (not like in IL2BOS where he would be

pointing its nose a bit lower - AT YOU and WITHOUT FALLING TROUGH THE AIR would already be hosing you with led). So from 3:48  that bf109 "looks to horizon"  but 

FALLS  BELOW and STOPS FALLING only at around min 3:52) In IL2 BOS planes don't fall through the air as they do in reality so staying on 6 is SUPER EASY and everyone feels as

an ACE. 

I would like those who want to express their opinion regarding this issue (if you think it is) to stay on subject .

Thank you, TRIAS. 

 

If you want any credibility whatsoever, you should present quantifiable data.  

 

I'm afraid a youtube video and people posting about their feelings just doesn't make a convincing argument.

[JG13_opcode]

usually maneuverable means unstable

 

 

Perhaps modern fighters with computer control would meet this definition, but not warbirds.  In order to be controllable without modern avionics, an aircraft has to meet the conditions for positive static stability.

 

Some aircraft had stability issues (e.g. spitfires with aftward CG shifts) but the designers always sought to correct them.

Edited July 4, 2016 by 13GIAP_opcode

[Dakpilot]

It is always important to remember that a BF 109 actually has a higher power to weight ratio than a Pitts special and probably has less wing area/drag?

 

very maneuverable Pitts special, Extra 300 etc, do not have much modern computer control  , have flown a Pitts and also a Chipmunk which is very stable/docile but yet also incredibly 'maneuverable' and both when compared to General aviation Cessna's and Piper's could be considered 'unstable' in that respect, whilst still meeting 'positive stability' criteria 

 

Just a bit of food for thought 

 

Cheers Dakpilot

[JtD]

The best conventional manoeuvrability is obtained in highly stable aircraft with large control surfaces (or just very effective ones) that require low operating forces.

 

High stability means that after a disturbance changing the balance, be it control input, a gust or anything, the plane settles at the new balance very quickly. It's desirable because it makes precise flying in quick manoeuvres very easy.

 

While you can obtain the same manoeuvrability with lower stability and less effective control surfaces, it is less desirable because the plane needs more time to settle at the new balance. Alternatively, the pilot of the less stable plane can work harder on the controls.

[JG13_opcode]

It is always important to remember that a BF 109 actually has a higher power to weight ratio than a Pitts special and probably has less wing area/drag?

 

very maneuverable Pitts special, Extra 300 etc, do not have much modern computer control  , have flown a Pitts and also a Chipmunk which is very stable/docile but yet also incredibly 'maneuverable' and both when compared to General aviation Cessna's and Piper's could be considered 'unstable' in that respect, whilst still meeting 'positive stability' criteria 

 

Just a bit of food for thought 

 

Cheers Dakpilot

 

Nope, sorry, GA aircraft are simply not certified as safe unless they are stable.  Don't confuse agility with stability.

 

An unstable aircraft is not controllable without computer assist, such as the F-16 which was IIRC the world's first.

[Dakpilot]

There are many aircraft that were designed to be unstable without computer assist..from WW1 onwards, rather take my statement as 'less stable' than GA aircraft

 

I think we can take it as a given that we are not talking about F16 or F22 type of designed for fly by wire "unstable" 

 

Stability is a complicated subject to define, and there is enough info available for me not to try and go into it

 

here is a very simple description 

 

http://aviation.stackexchange.com/questions/8049/are-fighter-jets-designed-to-be-so-inherently-unstable-that-a-human-cant-fly-on

 

Cheers Dakpilot

Edited July 4, 2016 by Dakpilot

[JG13_opcode]

There are many aircraft that were designed to be unstable without computer assist

 

Maybe when you say "unstable" you mean something other than what I mean.

 

When an aircraft is not statically stable it is unsafe to fly without computer assist.

 

 

 

Stability is a complicated subject to define

 

 

Not really, it's just that people misuse the term "stability".  It's actually a very precisely-defined and well-studied area of flight.  The link you posted contradicts what you are saying.  In the longitudinal case the static stability condition is satisfied by locating the CG ahead of the neutral point.

 

Relaxed stability is not the same thing as being unstable.  This is basic undergraduate stuff.

Edited July 4, 2016 by 13GIAP_opcode

[Dakpilot]

Not everyone here is totally educated to graduate level aerodynamics

 

let's just be happy and say ''less stable" and agree that a Pitts special or Extra 300 is less stable when compared to a GA Piper

 

Cheers Dakpilot

[JG13_opcode]

 

 

let's just be happy and say ''less stable" and agree that a Pitts special or Extra 300 is less stable when compared to a GA Piper

 

 

ok

[BlackBadger]

and "less stable" therefore really means more maneuverable and not really unstable?

[JtD]

No, it means that that you can obtain the same degree of manoeuvrability with aerodynamically less effective controls and more work on the controls by the pilot.

[Dakpilot]

and "less stable" therefore really means more maneuverable and not really unstable?

 

Yes and No, I have never flown a BF109 of any model, but if you fly a Pitts Special after flying a GA Piper Cherokee you would certainly say it was unstable, in general terms

 

true it (Pitts)does not have negative longitudinal stability like an F16, but it is not designed to be stable

 

"From now on, low stability was a prime requirement for fighters and aerobatic aircraft. Static stability is proportional to the control forces (more precisely: To the hinge moment of the respective control surface), so reducing stability gave pilots more response for the same effort. Longitudinal static stability is measured as the relative distance between neutral point (NP) and the center of gravity (CG). See here for more. Longitudinal static stability is achieved by placing the CG ahead of the NP. Shifting the CG back gives you a more responsive airplane, but also one which is more easily disturbed by gusts."

 

One large 4 engine Cargo aircraft of WWII era I used to fly, which had very (and widely reported) sweet handling, however was a huge handful to fly at cruise at Max weight (within CG limits) and almost impossible to trim for level flight, it required serious constant micro managing of controls to avoid "falling off the step" and a large power increase to get back up to correct Alt, not good for fuel consumption considerations on an 11 hour flight

 

It was considered 'unstable' and was a huge workload until several hours of fuel had been burnt off.

 

In BoS with some sensitivity dialed out I don't find the 109 much of an issue, true it is not perfect and the E model is sweeter, but there are a few differences between the E and F/G and many pilot's (not WWII) have commented on the different handling

 

Personally I find BoS style more plausible compared to Original 'on rails' IL-2 from my experience, nothing is perfect and I also hope for improvements

 

My only point was that a 109 has very similar (greater) Power to weight as a Pitts Special and is also not designed to be stable like GA aircraft, this is all   

 

Cheers Dakpilot

[Crump]

Perhaps modern fighters with computer control would meet this definition, but not warbirds.  In order to be controllable without modern avionics, an aircraft has to meet the conditions for positive static stability.

 

Some aircraft had stability issues (e.g. spitfires with aftward CG shifts) but the designers always sought to correct them.

 

Yes.

 

[Crump]

 

 

My only point was that a 109 has very similar (greater) Power to weight as a Pitts Special and is also not designed to be stable like GA aircraft, this is all   

 

The Bf-109 is famous for its stability.  It was a departure from previous and wrong thinking of most fighter designers in World War II.  Most fighters were airplanes that weapons were stuck on almost as a afterthought.

 

Willy Messerschmitt designed a gun platform and put wings on it.  You can see that if you know how to read stability plots.

 

 

 

The Spitfire Mk V at 31.4% MAC (Normal CG position) had very weak almost neutral stability.  You can see the slope of the curve is almost zero.

 

[CisTer-dB-]

Crump all your pictures in your post are broken links. Maybe you want to re-post them

[Crump]

The Bf-109 is famous for its stability.  It was a departure from previous and wrong thinking of most fighter designers in World War II.  Most fighters were airplanes that weapons were stuck on almost as a afterthought.
 
Willy Messerschmitt designed a gun platform and put wings on it.  You can see that if you know how to read stability plots.

 

 

The Spitfire Mk V at 31.4% MAC (Normal CG position) had very weak almost neutral stability.  You can see the slope of the curve is almost zero.

 

 

 

13GIAP_opcode, on 03 Jul 2016 - 21:46, said:

Perhaps modern fighters with computer control would meet this definition, but not warbirds.  In order to be controllable without modern avionics, an aircraft has to meet the conditions for positive static stability.

 

Some aircraft had stability issues (e.g. spitfires with aftward CG shifts) but the designers always sought to correct them.

 

Yes

 

[CUJO_1970]

Do share a track, it will be interesting to compare. From my experience one can recover very smoothly from a hammerhead in this game, but besides fuel and etc. the biggest opponent of a smooth recovery is strong torque. I tested it today, in the Bf-109E with the needle at about 1.1 Ata things went pretty smooth without much issue, but for comparison if I try to do that in the La-5 at 2.300 RPM and MP at 10.5 the aircraft starts rolling around the engine and drops into an awkward spin.

Congratulations that you can put any Soviet aircraft into an "awkward spin". That must have taken considerable effort. Thankfully they are equipped with insta-recovery when you do force them to depart.

 

Well done, sir.

[216th_Lucas_From_Hell]

?

[Caudron431]

?

[Edited]

 

This entire post was deleted and a PM has been sent. 

Edited July 20, 2016 by Bearcat

[1PL-Husar-1Esk]

Is he kidding or what?

[216th_Lucas_From_Hell]

Nope, he is 100% correct. The evil Russian bias is too much, and the poor experten are being actively discriminated against. I feel bad for them, sitting in their metallic coffins... if only they could trade their Messerschmitts for Polikarpovs, then they would stand a chance.