[CLOSED]Bf-109 Trim controls

[Echo38]

If you are trying to trim the 109 for max speed, I am not sure what you are doing.

 

For myself, I trim out completely when I'm extending. You know, when you're running from an airplane that's slightly slower but more maneuverable than yours, and you're on the deck and have little choice but to be pretty much straight and level, other than a slight amount of bobbing to throw his aim off (but not so much that you can't increase separation). In these cases, I'm at top speed (usually higher, for a while, as I just came out of a dive), and if I don't trim out, I need to hold quite a bit of forward stick during a chase that often lasts several minutes.

 

I understand that some people don't find the 109 comfortable to fly in some cases, but its arguable whether or not the trim tabs would do much to help

 

This is true. I can barely fight for a few minutes in the P-51D without my hands starting to hurt, because I don't have time to adjust all the trim every time my speed changes during the dogfight. I didn't mean to imply that adding the desired function to the 109 would suddenly make me magically able to fly it; I probably would still struggle to do more than touch-and-goes. I meant, rather, that my own hand problems cause me to be more sympathetic with the guy with the un-modded Warthog who's really wishing he could trim a little bit more nose-down, to reduce wear on his hand. Thrustmaster joysticks have very strong springs, for such a short-throw device.

[NineLine]

Have you tried using an extension with you injuries? Sorry not trying to change the subject, but just popped into my head to ask if that would, or does help with your troubles...

[Echo38]

Hmmm. I'm certain it would help immensely to have a simming stick that were more similar, in length & position, to that of real fighter. Haven't tried one, yet, due to logistical difficulties.

 

From my few hours flying real airplanes (years ago), I feel confident that a good simpit would solve pretty much all of my medical-related flightsim woes (which are all ultimately ergonomic problems, which aren't present in the real aircraft), but that's way out of my reach now, both in terms of technical skills & money. A simple stick extension mod would be far cheaper, of course, but does anyone even make one for the T-16000M? And I don't have the means to perform the modifications myself, to say nothing of what I'd need to do to my desk & chair, to make it all fit ...

 

In other words, "Damn it, Jim, I'm a pilot, not a ground crewman!" Which is a little ironic, given what we were just discussing a few posts back. But I'd love to hear anything about a cheap solution that doesn't require one to be handy with tools. Ever since the surgeries, I can barely scratch out a few hand-written sentences, much less effectively wield a screwdriver. (As you can see, typing long-winded posts is no problem; ha-ha!)

Edited June 25, 2015 by Echo38

[hegykc]

I won't say who's wrong and who's right, most of you debating are much more knowledgeable about the aircraft performance part of this debate. This might not be directly related to the subject, but indirectly it might be the very cause someone thinks a certain performance cannot possibly be correct because it's just too uncomfortable (for a simmer with a joystick).

 

Real world flying:

 

Desktop flying:

 

Using ones wrist joint and lower arm muscles for demanding and continuous work is completely wrong and unnatural. Of course, a desktop joystick is a cheaper and simpler solution than an extension and a center mount, but that doesn't lessen the fact that it's a completely wrong setup. ( I still fly with a desktop joystick, so no bias here )

 

The upper body muscles are several times stronger. Shoulder and elbow have enormously more freedom of movement than the wrist.

 

So the wrist joint has much less movement and is much weaker, yet it has to perform tasks that are much more demanding. Because in a real aircraft like the 109 the top of the grip is probably more than 20 inches away from the pivot point, while on a desktop joystick it's 8 inches at best. A much shorter lever to help your weak wrist out.Meaning double the deflection needed for the same effect of it's real world counterpart and double the strength needed, all the while using a body joint that has several times less movement and strength then the ones used for it's real world counterpart.

 

Completely underrated is the fact that the real world pilot has one muscle for each of the controls inputs. One muscle for left roll, another for right roll etc. Meaning that in the most demanding maneuvers 50% of his muscles are still relaxing, and preparing to be up for work next.While at the wrist, even on a single control input like left roll, all of the muscles are engaged, therefore none is ever relaxed.

 

There are just so many things, on top of each other, wrong with the geometry of desktop joysticks, multiplying the inconvenience and discomfort of flight that it boggles my mind we still do it :) So when you complain about something not feeling right, being weird or uncomfortable, just keep in mind that you are testing it on a completely wrong setup.

 

My main point is: What is a complete discomfort and weird to understand for a simmer, might have been just a minor inconvenience for a pilot, and completely worth it for the engineer trying to make the plane lighter and faster.

 

I will finish with a parallel that might put things into perspective:

 

You are being asked to paddle your bicycle with your wrist & fist (not even with your arm!)... and somehow it doesn't feel right and is uncomfortable. Could it be that there's something wrong with the test setup here?? :D

 

Again, not saying anyone is wrong requesting realism, or if that request is right or not. BUT if you're requesting complete realism, it would only be fair to first get a completely realistic setup to test on. :joystick:

Edited June 26, 2015 by hegykc

[Ala13_ManOWar]

Thank you hegykc!!!

 

I tried to say exactly that over a bunch of posts, but your explain is definitive ;) .

 

S!

[Yo-Yo]

I won't say who's wrong and who's right, most of you debating are much more knowledgeable about the aircraft performance part of this debate. This might not be directly related to the subject, but indirectly it might be the very cause someone thinks a certain performance cannot possibly be correct because it's just too uncomfortable (for a simmer with a joystick).

 

Real world flying:

 

Desktop flying:

 

Using ones wrist joint and lower arm muscles for demanding and continuous work is completely wrong and unnatural. Of course, a desktop joystick is a cheaper and simpler solution than an extension and a center mount, but that doesn't lessen the fact that it's a completely wrong setup. ( I still fly with a desktop joystick, so no bias here )

 

The upper body muscles are several times stronger. Shoulder and elbow have enormously more freedom of movement than the wrist.

 

So the wrist joint has much less movement and is much weaker, yet it has to perform tasks that are much more demanding. Because in a real aircraft like the 109 the top of the grip is probably more than 20 inches away from the pivot point, while on a desktop joystick it's 8 inches at best. A much shorter lever to help your weak wrist out.Meaning double the deflection needed for the effect of it's real world counterpart and double the strength needed, all the while using a body joint that has several times less movement and strength then the ones used for it's real world counterpart.

 

Completely underrated is the fact that the real world pilot has one muscle for each of the controls inputs. One muscle for left roll, another for right roll etc. Meaning that in the most demanding maneuvers 50% of his muscles are still relaxing, and preparing to be up for work next.While at the wrist, even on a single control input like left roll, all of the muscles are engaged, therefore none is ever relaxed.

 

There are just so many things, on top of each other, wrong with the geometry of desktop joysticks, multiplying the inconvenience and discomfort of flight that it boggles my mind we still do it :) So when you complain about something not feeling right, being weird or uncomfortable, just keep in mind that you are testing it on a completely wrong setup.

 

My main point is: What is a complete discomfort and weird to understand for a simmer, might have been just a minor inconvenience for a pilot, and completely worth it for the engineer trying to make the plane lighter and faster.

 

I will finish with a parallel that might put things into perspective:

 

You are being asked to paddle your bicycle with your wrist & fist (not even with your arm!)... and somehow it doesn't feel right and is uncomfortable. Could it be that there's something wrong with the test setup here?? :D

 

Again, not saying anyone is wrong requesting realism, or if that request is right or not. BUT if you're requesting complete realism, it would only be fair to first get a completely realistic setup to test on. :joystick:

 

So, Airbus and F-XX that use sidesticks are all unnatural?

[hegykc]

Airbus is fly-by-wire so no high forces, and it's also civilian so no dogfighting and tiring wrist maneuvers, but smooth, light and very rare inputs during a long and uneventful flight. Most of the time the airplane is controlled by dials on the auto pilot.

 

F-16 uses force sensing so you still use your upper body and upper arm muscles to exert force horizontally (yes it twist somewhat but a miniscule amount), not twist your wrist to exert angular movement. It's also a modern jet where your goal is to engage as far away as possible without ever getting into a maneuvering fight , where the WWII pilots goal is quite opposite. Get as close as possible therefore throwing him into a high stick force dogfight almost every time. In addition to that it has a 25 lbs force limit. P-51 required about 90 lbs for a 5G turn. Try that with your wrist :)

 

F-22 and F-35 also force sensing? And BVR and electronic/hydraulic enhancements instead of close up mechanical dogfighting.

 

Of course joystick forces are nowhere near any of those mentioned, but still too much for the wrist muscles, unnatural and nowhere near the precision. And that's where the simmers "this can't be right?" comes from, I think.

 

Maybe none of the pilots complained about the forward stick during high speeds because there wasn't a need to? No center detent to chase all the way, two and a half times more leverage regarding stick length and several times stronger muscle used. Just maybe it was piece of a cake to do that, just like some of the guys here with extensions are saying it is. Now get back to constantly having your wrist rotated forward for a 10 minute flight, which is by the way THE most uncomfortable, unnatural and limited wrist movement of all 4 of them (oh the irony)... and I can completely see why there would be a disagrement between simmer and performance evidence, resulting in "this can't be right?".

 

What's not right is your stupid desktop joystick, that's what :) And mine too :)

Edited June 26, 2015 by hegykc

[Echo38]

F-16 uses force sensing so you still use your upper body and upper arm muscles to exert force horizontally (yes it twist somewhat but a miniscule amount), not twist your wrist to exert angular movement. It's also a modern jet where your goal is to engage as far away as possible without ever getting into a maneuvering fight , where the WWII pilots goal is quite opposite.

 

[nod] And, furthermore, the F-16 has that full-authority FBW, with all the assists; the computer's doing much of the flying for the pilot. Hell, it won't even let you exceed max alpha.

 

Good diagram--it pretty much sums up what I've spent hours trying to explain to various people over the years.

[gavagai]

Not on the 109.

 

And I meant to develop it properly, not to be a lua file edit.

 

I think you're reaching here, Sith. Lua is just a convenient metalanguage. Or are you concerned that yo-yo doesn't have to dig into C++ to adjust it?:smartass:

 

The argument is more or less over then. It will make many of us happy if we can adjust the 109 elevator trim tab, find something we like, and then leave it there.

 

Ta ta for now.:thumbup:

[NineLine]

I think you're reaching here, Sith. Lua is just a convenient metalanguage. Or are you concerned that yo-yo doesn't have to dig into C++ to adjust it?:smartass:

 

The argument is more or less over then. It will make many of us happy if we can adjust the 109 elevator trim tab, find something we like, and then leave it there.

 

Ta ta for now.:thumbup:

 

You guys will be just fine without it...

[AussieFX]

So that's why I was burying my twin squirrel into the ground after the surgeon removed my lat dorsi? :joystick:

 

I know I don't play with the 109 as much because I do find it tiring after a half hour. I'm using a G940. I have an FFB2 in the cupboard I should pull it out and see if that is any better.

[AussieFX]

I just had a quick and dirty play with my 109.

Used the free flight option in one of the quickstart menus, so I didn't check temperature, pressure or wind and fuel load was probably at 100%.

 

Flying at 500km/h straight and level ~14 ata, 2500rpm at 2500m with full down trim I was getting a climb rate of 5m/s hands off.

At cruise speed and settings I had to trim it slightly up. I'm using a G940.

One thing I did note was if the ball is even slightly off centre it will head for the stars - rapidly.

All in all it flew as I expected in my oh so quick test.

 

However not being a fixed wing pilot nor ever having been in the military I don't understand why so much up/positive trim is available. I think fighters of the era were designed to be slightly unstable? Anyone care to comment?

[hegykc]

I don't understand why so much up/positive trim is available

 

Could it be there in case of damage emergency? What happens if your elevators, wings and flaps are shot up. Did I read here the plane was nose heavy, or it could become that if the wings lost lift due to damage? So with the stick useless in pitch, it could still be controlled by trim?

Edited June 26, 2015 by hegykc

[Anatoli-Kagari9]

Could it be there in case of damage emergency? What happens if your elevators, wings and flaps are shot up. Did I read here the plane was nose heavy, or it could become that if the wings lost loft due to damage? So with the stick useless in pitch, it could still be controlled by trim?

 

Very interesting view! Well thought, and I just wonder if indeed that was the case ?

 

Also, at full tanks, and carrying bombs, I don't know if higher tail heavy trim settings would be required too ?

Edited June 26, 2015 by jcomm

[VO101_MMaister]

Having a full scale flight stick , designed after the exact measurments (regarding length and travel) of the 109`s control column (with much lower load than the real one ) I can tell you guys that it is still quite uncomfortable to fly with a continously out of trimm aircraft. So it is not a solution itself. Longer column means longer distance where you need to hold the stick to fly straight.

What is more important maybe is the fact that the warthog has center detent and a relatively high load around it. What can make it a pain to hold it out of its center. Keeping it in focus, even a short stick with a higher quality gimbal can offer a big progress.

[Yo-Yo]

Could it be there in case of damage emergency? What happens if your elevators, wings and flaps are shot up. Did I read here the plane was nose heavy, or it could become that if the wings lost lift due to damage? So with the stick useless in pitch, it could still be controlled by trim?

 

Right. Elevator is fabrique coated, so, the possibility of having only 1/2 of it after a shell hit is very high. If you get caught in a dive you have to recover using only 1/2 of an elvetor.

To land a plane you have to achieve AoA for 3-points landing that requires a lot of elevator input. That's why it's vital to have excessive ability to pitch up.

 

Trimming the plane for dive can be dangerous at recovering: for example, if the pilot catches GLOC free stick will keep creating g-load for recovering. THe plane will go up performing a loop and the pilot has chances to survive. If the plane is trimmed for the dive speed.... the pilot will wake up just before St. Peter's eyes.

[Kurfürst]

I bit a of a side question, but why was fabric used/preferred so long for control surfaces?

 

Even though many planes switched to light metal cover on some control surfaces when problems arose with balooning at high speed for example, but the industry standard remained fabric for a curiously long time... was there any inherent advantage to it, besides lightness?

[Yo-Yo]

I bit a of a side question, but why was fabric used/preferred so long for control surfaces?

 

Even though many planes switched to light metal cover on some control surfaces when problems arose with balooning at high speed for example, but the industry standard remained fabric for a curiously long time... was there any inherent advantage to it, besides lightness?

 

I guess it gives advantages of composites. Fabric and a kind of resin gives very light and strong surface.

[DB 605]

Please provide a solid proof of your statement about incorrect modelling, or your statement will be considered as a baseless bashing. I tried to be as patient as I could but even my angel's patience has the limit...

 

 

Yo-Yo, i'm certainly not try to bash the modelling of DCS, and unfortunately i don't have "solid" proof about it but could you please explain IF trim modelling is currently correct, then why aren't we able to replicate this in DCS (quote from my other post:

 

" Indeed. I've just read another real life bf 109 pilot (Väinö Pokela) sentences wich makes me doubt there is still something weird in DCS 109 trimming. He was very experienced 109 pilot as he flew them from 1943 to 1947. At some point, he became instructor to the new 109 pilots and he wrotes: "...to the students i adviced way (to jump out of the plane if needed): hold on the stick strongly and at same time wind up trimmer wheel to fully forward (nose down). Then let go off from the stick. Then pilot will fly off from the cockpit like a cork from bottle." Source: Bf 109 ja saksan sotatalous book by prof. Hannu Valtonen. (translated by me, may contain some minor mistakes)"

[NineLine]

Just to make sure I am reading that right, is he saying the aircraft would become very heavy nose down with full nose down trim, enough to launch the pilot out of his seat for the purposes of bailing out? Does it say speed, etc? Also what variant was he talking about? I have never really seen anyone talk like this about the 109 trim, I wonder if its something lost in translation.

[DB 605]

Just to make sure I am reading that right, is he saying the aircraft would become very heavy nose down with full nose down trim, enough to launch the pilot out of his seat for the purposes of bailing out? Does it say speed, etc? Also what variant was he talking about? I have never really seen anyone talk like this about the 109 trim, I wonder if its something lost in translation.

 

Yes indeed, very nose heavy. I have actually read this kind of behaviuor from quite many (messerschmitt) pilot memoirs. He is talking about G2 and G6 models, and no, i don't think it's about my crappy translation. Unfortunately no speed figures or other information available.

[NineLine]

Yes indeed, very nose heavy. I have actually read this kind of behaviuor from quite many (messerschmitt) pilot memoirs. He is talking about G2 and G6 models, and no, i don't think it's about my crappy translation. Unfortunately no speed figures or other information available.

 

DO you have other quotes handy? Not sure I have seen anything like this before, I have seen issues with heavy nose trim and dives, but nothing about using it to get out of the cockpit easier :)

[MiloMorai]

Have read about Allied pilots doing such maneuver > slam stick forward tho.

[DB 605]

DO you have other quotes handy? Not sure I have seen anything like this before, I have seen issues with heavy nose trim and dives, but nothing about using it to get out of the cockpit easier :)

 

I will post them up if find some. Problem is i've read so many books that i can't remember exactly who said what etc. :)

[NineLine]

I will post them up if find some. Problem is i've read so many books that i can't remember exactly who said what etc. :)

 

No worries... I think there is more too it then just full nose heavy trim (not saying you are lying or wrong) but it just seems so different than what test data we have seen/been shown.