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Hello, I've noticed two things while flying the Bf-109 and using the horizontal stabilizer and have questions concerning them.

 

1. The flight stick doesn't change its position when using the stabilizer, only the elevator changes its position. Is this normal? When using regular trim wheels on other aircraft, it does change its position, so I'm wondering why this is not the case here.

 

2. Even when "trimming" it fully down, the aircraft still wants to climb, this is extreme directly after lift-off. In IL-2 for example, this is not the case and the plane is far more pleasant to fly/take off because of this. So I'm guessing which is more realistic.

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Hi Metalfan,

 

1. The trim on the 109 works differently than trim on most aircraft. Adjusting the trim wheel in the 109 changes the angle of the entire horizontal stabilizer and not necessarily the elevator (not visually modeled afaik). I'm not 100% sure what other aircraft you refer to however by my understanding the convential trim setup on an aircraft is accomplished using Trim tabs (see google for pictures if you like). Trim tabs work more or less the same way as control surfaces do and influence how much lift a control surface generates to more or less hold it in a certain position. Since the control surfaces are linked to the stick this would cause the stick to move in the cockpit.

 

2. I've never flown the 109 for real so I can't say anything with 100% accuracy here but to my understanding ED creates their FM's only with as much 'scientific data' as they can get their hands on. Ie flight test and wind tunnel data of real a/c and scale models, all of it from multiple sources usually. I'm not sure how the IL-2 devs create their FM's and I'm also not saying that ED is always perfect and never makes mistakes but how an aircraft behaves in another sim isn't necessarily a great guideline for what is realistic.

 

What I can tell you is that from a virtual pilots point of view I mostly fly with full nose down trim or a little less and don't have many issues with the aircraft pitching up. With this method you actually need a little bit of pull to get airborne on takeoff.


Edited by DefaultFace
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9./JG27

 

"If you can't hit anything, it's because you suck. If you get shot down, it's because you suck. You and me, we know we suck, and that makes it ok." - Worst person in all of DCS

 

"In the end, which will never come, we will all be satisifed... we must fight them on forum, we will fight them on reddit..." - Dunravin

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Good info!

 

Just as a side note: when using the in-cockpit trimmer, you can see the animation of the horizontal stabilizer from the F2 view just fine. :)

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Just checked it out, very nice! Not sure if I missed that before or if it was recently implemented but definitely looks cool.

9./JG27

 

"If you can't hit anything, it's because you suck. If you get shot down, it's because you suck. You and me, we know we suck, and that makes it ok." - Worst person in all of DCS

 

"In the end, which will never come, we will all be satisifed... we must fight them on forum, we will fight them on reddit..." - Dunravin

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Hi Metalfan,

 

1. The trim on the 109 works differently than trim on most aircraft. Adjusting the trim wheel in the 109 changes the angle of the entire horizontal stabilizer and not necessarily the elevator (not visually modeled afaik). I'm not 100% sure what other aircraft you refer to however by my understanding the convential trim setup on an aircraft is accomplished using Trim tabs (see google for pictures if you like). Trim tabs work more or less the same way as control surfaces do and influence how much lift a control surface generates to more or less hold it in a certain position. Since the control surfaces are linked to the stick this would cause the stick to move in the cockpit.

 

2. I've never flown the 109 for real so I can't say anything with 100% accuracy here but to my understanding ED creates their FM's only with as much 'scientific data' as they can get their hands on. Ie flight test and wind tunnel data of real a/c and scale models, all of it from multiple sources usually. I'm not sure how the IL-2 devs create their FM's and I'm also not saying that ED is always perfect and never makes mistakes but how an aircraft behaves in another sim isn't necessarily a great guideline for what is realistic.

 

What I can tell you is that from a pilots point of view I mostly fly with full nose down trim or a little less and don't have many issues with the aircraft pitching up. With this method you actually need a little bit of pull to get airborne on takeoff.

 

Thanks for the info, I didn't know that nearly full down trim is used on modern aircraft to keep them flying straight. :thumbup:

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Sorry meant to write 'virtual pilot' that comment was referring to the 109 in dcs and not any real aircraft.

9./JG27

 

"If you can't hit anything, it's because you suck. If you get shot down, it's because you suck. You and me, we know we suck, and that makes it ok." - Worst person in all of DCS

 

"In the end, which will never come, we will all be satisifed... we must fight them on forum, we will fight them on reddit..." - Dunravin

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2. Even when "trimming" it fully down, the aircraft still wants to climb, this is extreme directly after lift-off.

 

This has been discussed a lot already. No one can figure out why the trim would work that way, but ED insists that it is correct. They went so far as to make the aileron and rudder trim tabs adjustable in the settings, but not the elevator trim tabs...:music_whistling:

P-51D | Fw 190D-9 | Bf 109K-4 | Spitfire Mk IX | P-47D | WW2 assets pack | F-86 | Mig-15 | Mig-21 | Mirage 2000C | A-10C II | F-5E | F-16 | F/A-18 | Ka-50 | Combined Arms | FC3 | Nevada | Normandy | Straight of Hormuz | Syria

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They went so far as to make the aileron and rudder trim tabs adjustable in the settings, but not the elevator trim tabs...:music_whistling:

 

I believe that's due to an internal flight dynamics model limitation - not being able to have a 2nd order trimming ... stabilator + elevator trim tab like in the real aircraft, otherwise they would have added that option as they did for aileron and rudder.

 

IMO that's also what distinguishes the ED Bf109 K4 from the 109s in the other mentioned simulator, which models both the stabilator ( of course ) and has a trim tab, set at a fixed position but properly calibrated to allow for more realistic feel ( as far as I believe to be the case IRL ) regarding pitching moments. On that sim, with the aircraft on ground, braked, one can actually observe the elevator move (and the stick in the cockpit too ) due to propwash when the engine power is increased during a run-up, because the elevator trim tab is set for nose heavy ( deflected up at a fixed position as can be observed by zooming into it ).

 

Anyway, it's been a while since I used DCS, and this particular module, and I've read somewhere that there was some fine tuning done in the latest releases ( ? ) and that this pitching moment effect had been tuned down ( ? )


Edited by jcomm

Flight Simulation is the Virtual Materialization of a Dream...

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This has been discussed a lot already. No one can figure out why the trim would work that way, but ED insists that it is correct. They went so far as to make the aileron and rudder trim tabs adjustable in the settings, but not the elevator trim tabs...:music_whistling:
Sorry mate, but you aren't being honest here :mad:. It's being posted several times at these forums some Germans charts trying to disprove that feature, just to prove it is perfect as it is (and proving also people don't know how to read charts…). Trim limit is a feature due to movable stabilizer as you can over-trim for high speeds leading to a crossed controls situation where you have to pull from stick to keep nose down and vice-versa so trim was limited to prevent that situation. Also real examples nowadays fly like that, confirmed by test pilots flying those. So yes, 109 was like that, and no other ""simulators"" out there aren't right, just they make it easy and comfortable for playstation users, but not real. So, no only DCS model is perfect as it is but the reason why it is like that is very clear and proven by German documents. Please stop saying "nobody knows why" :doh:.

 

 

S!

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

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You are being very uncharitable if your first conclusion is that I'm being dishonest. I'm not the best writer, so please take it easy with the accusations. I am very aware of the technical documents that have been presented, and other pilot reports have been presented here that tell a different story.

 

I remain respectfully not-fully convinced.:no:


Edited by gavagai

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Are we still talking about this when the lift up effect is only present at take off (like every report of the 109 states) and with proper settings you don't get this lift up effect during flight anymore?

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, just they make it easy and comfortable for playstation users, but not real.

S!

 

Wanting a sim to be as hard as possible doesn't make it as realistic as possible.I would say that playing il2 46 with the stick i used to play it the first time is more difficult than playing DCS with a quality stick.

Also when the 109 Fm changed it made it easier to control on the edge of the stall.So sometimes easy means more realistic.

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You are being very uncharitable if your first conclusion is that I'm being dishonest. I'm not the best writer, so please take it easy with the accusations. I am very aware of the technical documents that have been presented, and other pilot reports have been presented here that tell a different story.

 

I remain respectfully not-fully convinced.:no:

I don't "accuse" you mate, never mean that :smilewink:, but you cannot say "we don't know why it's like that" because it's been discussed exhaustively right here, we know exactly why and it's perfectly consistent with sources. Those "reports" some of you claim, usually grandpa's stories collected from the internet, aren't "sources", not to mention some members like to cherry pick when not misread the ones matching what they want it to be. Show us those German reports again, I repeat German 1940's engineering reports, and demonstrate us how everybody is mistaken because we read them wrongly even though they said in 1943-44 109 was exactly like it currently is in DCS.

 

 

Wanting a sim to be as hard as possible doesn't make it as realistic as possible.I would say that playing il2 46 with the stick i used to play it the first time is more difficult than playing DCS with a quality stick.

Also when the 109 Fm changed it made it easier to control on the edge of the stall.So sometimes easy means more realistic.

Who says I nor anybody wants it just difficult? I don't want it just difficult, I want it real. But realism, even though sometimes means "easier" than RL, usually are not because aeroplanes has quirks and vices that regular games don't bother to represent. DCS is easier than other simulators indeed in many aspects, just featuring a RL behaviour, but in other ones it is quite more difficult as it is RL because DCS features those behaviours, unseen in any other simulator out there to the day. It would be stupid just doing it "difficult" to make it appear more realistic than it is… oh wait, I know a couple "simulators" doing that :lol:. One of them had a patch today, it completely changed all the FM and physics in every aircraft. Can you please exaplin how on Earth a real simulator, not a game, can change everything from patch to patch just because gamers complain about they don't like this or that on game balance? That's the difference between realism and games mate :smilewink:.

 

 

Are we still talking about this when the lift up effect is only present at take off (like every report of the 109 states) and with proper settings you don't get this lift up effect during flight anymore?
You mean engine torque? Yes, it's a matter of engine torque indeed :thumbup:.

 

 

S!


Edited by Ala13_ManOWar

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

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Those "reports" some of you claim, usually grandpa's stories collected from the internet, aren't "sources", not to mention some members like to cherry pick when not misread the ones matching what they want it to be. Show us those German reports again, I repeat German 1940's engineering reports, and demonstrate us how everybody is mistaken because we read them wrongly even though they said in 1943-44 109 was exactly like it currently is in DCS.

 

Yes, please do show me the report.:smilewink: Asking for historical documents before the other guy does not automatically place the burden of proof on him. The burden of proof is on the one who is convinced he is correct, and I do not claim to be correct about anything.

 

If there is a published procedure for the 109K-4 that says the elevator trim should be set fully nose-down that would be something.

P-51D | Fw 190D-9 | Bf 109K-4 | Spitfire Mk IX | P-47D | WW2 assets pack | F-86 | Mig-15 | Mig-21 | Mirage 2000C | A-10C II | F-5E | F-16 | F/A-18 | Ka-50 | Combined Arms | FC3 | Nevada | Normandy | Straight of Hormuz | Syria

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Yes, please do show me the report.:smilewink: Asking for historical documents before the other guy does not automatically place the burden of proof on him. The burden of proof is on the one who is convinced he is correct, and I do not claim to be correct about anything.

 

If there is a published procedure for the 109K-4 that says the elevator trim should be set fully nose-down that would be something.

It's being already posted like 3 thousand times in these forums, charts and also the famous dive test. Look for it, I'm not losing any time looking for or posting again what's being posted and discussed so many times :smilewink:. When you find it read again with a better open-minded attitude, may be you realize K4 should be even worst regarding trim and stick positionVsTAS (not to mention force applied to stick to keep straight flight, another chart already posted) than it is right now :lol:. Don't fool yourself, or try to do others, you do think you're right since you clearly said "nobody knows why it's like that", so you are absolutely convinced in your claims that it is wrong. Why would you say that otherwise?

 

On the contrary my friend, the "burden of proof" is on the people who claim it's wrong. ED makes their work, you buy it or not (and I mean both buy meanings here), they are professionals dedicated to simulation since 25 years ago but still they are open to mistakes correction given anybody provides a real evidence of it. To the day no one provided such an evidence. Who claims it's wrong has to prove it's wrong, so not me. Anyway, what I'm not as a user is being blind, I've followed those threads, I've read them, and I've seen those reports and charts, and you know what? I'm not an engineer but charts are obvious, they say what they say, they say you have to apply a determined amount of force to keep straight flight, they say why trim was limited to 1.15º nose down, and I see everything matches charts quite truthfully. Perfect? probably no and never would be as we don't have a time machine to get needed info, but with the current info available I see 109 module is outstanding in every bit. And don't get me wrong, I don't complain either about 109 or P-51, it's not a matter of "sides" here, not for me.

 

 

S!


Edited by Ala13_ManOWar

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

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On the contrary my friend, the "burden of proof" is on the people who claim it's wrong.

 

When two parties are in a discussion and one asserts a claim that the other disputes, the one who asserts has a burden of proof to justify or substantiate that claim.

https://en.wikipedia.org/wiki/Philosophic_burden_of_proof

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Is defining burden of proof really relevant here? Secondly one could argue with that definition that the burden lies with you as you are asserting the claim that ed is wrong. Or one could argue with the legal definition. Point is it's not relevant, there is a very very long thread on this topic already and the only way it'll be change is if you post evidence.

9./JG27

 

"If you can't hit anything, it's because you suck. If you get shot down, it's because you suck. You and me, we know we suck, and that makes it ok." - Worst person in all of DCS

 

"In the end, which will never come, we will all be satisifed... we must fight them on forum, we will fight them on reddit..." - Dunravin

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Ok,

 

at least you got me re-installing DCS 1.5.4 beta just to check how the 3 ww2 fighters have progressed through the latest patches...

 

Didn't have much time to test yet... but on a takeoff using 60% fuel, with trim set for +1.0, I found less pitching up moment than I used to the last time I tried it some 3 months ago...

 

Will test further ASAP and report.


Edited by jcomm

Flight Simulation is the Virtual Materialization of a Dream...

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Ok,

 

at least you got me re-installing DCS 1.5.4 beta just to check how the 3 ww2 fighters have progressed through the latest patches...

 

Didn't have much time to test yet... but on a takeoff using 60% fuel, with trim set for +1.0, I found less pitching up moment than I used to the last time I tried it some 3 months ago...

 

Will test further ASAP and report.

FM has changed Jcomm, it's not like night and day but changes are apparent. She's more comfortable to fly for you guys lacking a long stick, but still even myself having one can feel the difference. Overall she's a nicer model, it's not like she wasn't already but now is even more.

 

S!

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

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FM has changed Jcomm, it's not like night and day but changes are apparent. She's more comfortable to fly for you guys lacking a long stick, but still even myself having one can feel the difference. Overall she's a nicer model, it's not like she wasn't already but now is even more.

 

S!

 

Thx Ala13 :thumbup:

Flight Simulation is the Virtual Materialization of a Dream...

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Well,

 

been testing the latest beta version 1.5, and the 109.

 

Regarding this old subject, and loading fuel only up to 60%, I have made a few test flights and indeed the pitching up moment feels as having been tuned down.

 

Regarding the need to use fwd stick most of the time, even with full nose heavy stab trim, I still ask myself, comparing to my RL experience, what the trims are made for, in non-fbw aircraft ? Isn't it to release the pilot from these forces ? Or, as I often do in my glider, to increase those forces in order to avoid unwanted effects ( I always set the gliders nose heavy for approach and landing, in order to positively feel the force needed for flare... ).

 

The 109 has a fixed, ground adjustable elevator trim tab. What might it be used for other than to exactly fine tune this need to use stick fwd during takeoff or level flight over a wide range of speed and power settings ?

 

Why have the two other trim tabs ( aileron and rudder ) been made available to set in the aircraft settings, but not the elevator trim tab ?

 

If I were a 109 pilot I would certainly ask my ground crew to adjust it for me, then try to fine adjust it based on a series of flights... and I would certainly seek for a setting that would clear out that odd need to use significant fwd stick as soon as I leave ground as it is in DCS... That's what trims, and trim tabs are made for, I guess....

Flight Simulation is the Virtual Materialization of a Dream...

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Sorry mate, but you aren't being honest here :mad:. It's being posted several times at these forums some Germans charts trying to disprove that feature, just to prove it is perfect as it is (and proving also people don't know how to read charts…). Trim limit is a feature due to movable stabilizer as you can over-trim for high speeds leading to a crossed controls situation where you have to pull from stick to keep nose down and vice-versa so trim was limited to prevent that situation. Also real examples nowadays fly like that, confirmed by test pilots flying those. So yes, 109 was like that, and no other ""simulators"" out there aren't right, just they make it easy and comfortable for playstation users, but not real. So, no only DCS model is perfect as it is but the reason why it is like that is very clear and proven by German documents. Please stop saying "nobody knows why" :doh:.

 

 

S!

 

Really interesting, i have read a lot of original german documents to investigate this and i never read a instruction for full forward trim with the problem nose pitching up, but i saw some real life pictures from a BF 109 with bricks in his tail for extra weight.

Can you show me this German documents pleas?

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Well,

 

been testing the latest beta version 1.5, and the 109.

 

Regarding this old subject, and loading fuel only up to 60%, I have made a few test flights and indeed the pitching up moment feels as having been tuned down.

 

Regarding the need to use fwd stick most of the time, even with full nose heavy stab trim, I still ask myself, comparing to my RL experience, what the trims are made for, in non-fbw aircraft ? Isn't it to release the pilot from these forces ? Or, as I often do in my glider, to increase those forces in order to avoid unwanted effects ( I always set the gliders nose heavy for approach and landing, in order to positively feel the force needed for flare... ).

 

The 109 has a fixed, ground adjustable elevator trim tab. What might it be used for other than to exactly fine tune this need to use stick fwd during takeoff or level flight over a wide range of speed and power settings ?

 

Why have the two other trim tabs ( aileron and rudder ) been made available to set in the aircraft settings, but not the elevator trim tab ?

 

If I were a 109 pilot I would certainly ask my ground crew to adjust it for me, then try to fine adjust it based on a series of flights... and I would certainly seek for a setting that would clear out that odd need to use significant fwd stick as soon as I leave ground as it is in DCS... That's what trims, and trim tabs are made for, I guess....

Jcomm, maybe you forgot, but this was answered long time ago by Yo-Yo:

Putting trim tabs on the elevator might create unwanted effects if the players adjusted them too much. Besides of that, he felt that trim in the aircraft was sufficient as it is.

 

As for the limit of the trim, this was also explained long time ago, by a German high speed dive test document that showed, that if trimmed too much forward, the 109 was impossible to recover from a dive using the stick alone.

In order to alleviate this, the RL forward trim was reduced to what we have now.

 

Honestly, I'm a little bit tired to see this discussion show up again.

This was discussed exhaustively long time ago, and it seems as if even some of the participants back then have forgotten the explanations given.

 

To reiterate:

ED is in possession of plenty of documents.

They have had extensive interviews with both former WW II pilots as well as current 109 pilots about the 109 behaviour, even on this issue after it was brought up.

Yo-Yo is a thorough FM developer which makes sure that the DCS aircraft live up to recorded flight data from RL tests.

 

I can't really see that there is a basis for again beating this dead horse.

 

Anyway, if anyone think that something is "wrong", they would have to present solid evidence in the form of official test reports or thorough bug reports, otherwise it will not be taken into account by ED:

https://forums.eagle.ru/showpost.php?p=2642013&postcount=31=111

 

So, if that is not possible, maybe it is better to just leave the subject alone and enjoy the 109 as she is. ;)

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Hi Sporg,

 

thx for reminding me of that thread. It had been a while since I last played DCS...

 

I even contributed with some facts I gathered from some emails exchanged with Klaus Plaza, that actually confirmed the pitching up tendencies...

 

:-/

 

Let's leave it as it is - probably closer to real than anything else...

Flight Simulation is the Virtual Materialization of a Dream...

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