[CLOSED]Bf-109 Trim controls

[ElGringo]

YoYo if you realy don't want it to be changed by the players (for some reason) just set those trim tabs to cruise speed, because right now the 109 pilots need to trim down -2 all the way just to keep it level through most of the flight. Because of that, the plane can't trimed to nose down attitude.

 

Also, why would the pilot need -2 and 6+ horisontal stab trim if anything above 0 makes the plane loop on itself :P

 

+1 Trim tabs set to cruise speed by default would only make sense.

[Siegfried]

Somebody had noted elevator trim was changed in 1.2.16 or it's placebo effect from me? Now is more nose heavy with all stab forward in all speeds.

[Solty]

OK. So I made a video how 0 trim 109 is set in the air and controls are left alone. I give input only at the begining to keep it level(from 0:00 to 0:05), after that when I release the stick the plane flies on its own. I am not touching the stick nor rudder since 0:05 mark.

 

Again:

Trim set 0

Joystick neutral possition.

Full throttle. 1.8ata

That is why we need the elevator trim tabs to be set to cruise speed. To keep level at around 550kph. That would make the plane go a little bit nose heavy during take off and probably would fit within what IRL pilots said about 109s behaviour.

 

 

PS. This is new version 1.2.16.

[DieHard]

According to the manual, the trim is adjustable from -6 to +1.something degrees.

 

I understand a negative number to mean the elevator would be angled downwards by the said -6 degrees, and the positive means up for the +1.something degrees.

 

If that is the case, isn't the trim reversed? On takeoff, rolling in full down trim gives a reading of 2 on the trim gauge, and full up trim give a reading of -6.

 

The controls aren't reversed, but it seems to me that the trim works the opposite way to that intended. Is this a bug, or am I just reading it incorrectly, and there is more up trim than down, and a negative number means up trim is applied?

 

This would easily account for the fact that we can't seem to get sufficient down trim under most flight parameters.

 

Been flying it fine, in flight at cruise speed with +2 setting. Granted it takes a bit more stick work to fly it. I have to pay attention. When gear and flaps come down and later with bombs, rockets, or wing gun gondolas, the negative trim settings come in nicely or will be.

 

I can control too much altitude gain by using less throttle.

[DB 605]

But the trouble right now in DCS is that the trim range does NOT cover the whole speed range: At top speed you need to apply a bit of down elevator to stay level. If you let go of the stick the K4 climbs. Again, if you don't want to add a trim tab option for the elevator then how about adding a constant to the elevator hinge moment to offset the adjustable tailplane trim range to a more nose heavy range? Again, this would be "historically" correct since any pilot could do this. Why on earth would a pilot fly around in an airplane that you could not trim to level flight at high speed when all he needed to do was get the trim tab on the elevator slightly adjusted?

 

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)

 

Now try this same in DCS and plane doesen't go down even slightly...

[Anatoli-Kagari9]

Even at lower GWs ( less than 50% fuel ) I've been landing with -2.5 ( tail heavy ) with no problem...

[Kelevra]

I always fly with +2 (Nose Down) in cruising flight (2000 to 2400 rpm) . and I have little to do to keep the attitude level. I have read that it's a tail heavy plane. So it might be normal

[Solty]

I always fly with +2 (Nose Down) in cruising flight (2000 to 2400 rpm) . and I have little to do to keep the attitude level. I have read that it's a tail heavy plane. So it might be normal

What you are changing is the horisontal stabiliser trim. Not the elevator trim. The whole thing, not trim tabs.

 

The plane has additional trim tabs IRL, which are adjusted by the ground crew. Those are adjusted according to level flight at cruise speed. There were also alerion and rudder trim tabs which work the same way.

Let me quote again:

"These were fixed trim tabs and not movable by the pilot. They were bent by the ground crews at the first flights. So the Me109 was pre-trimmed for cruising speed."

http://www.wwiiaircraftperformance.o...28_ger_eng.pdf

:book:

 

It seems in DCS we have trim tabs set to 0 deg.:(

[Kelevra]

What you are changing is the horizontal stabiliser trim. Not the elevator trim. The whole thing, not trim tabs.

 

oh my bad !

 

yes it would be nice to have those options available in the ground crew menu.

 

with

flare gun,

water-methanol / gasoline

[shaunsh]

А как с этим меню разобраться?

--------------

здесь

[Page.Down]

I fly at +2 at all altitudes. If I set to 0 the K4 pitches hard up to the point of stall unless I put a negative G force on the nose. It's unnatural. And it doesn't matter what speed either. Which is why I use +2 all of the time.

[Solty]

I fly at +2 at all altitudes. If I set to 0 the K4 pitches hard up to the point of stall unless I put a negative G force on the nose. It's unnatural. And it doesn't matter what speed either. Which is why I use +2 all of the time.

Read page before. That is because elevator trim tabs are not adjusted and set to 0. That is why the plane flies that way. What you change is the horizontal stabilizer trim, which it seems is not enough to stop the 109's pitching moment.

Edited April 29, 2015 by Solty

[IIIJG52_Otto_]

I think the elevator trim bf-109 k4, remains bad modeled.

In this screenshot from 360º view of bf-109G4 of the Flugmuseum Messerschmitt, you can see that the normal elevator trim configutatión is -1 or negative (tail-down) not full nose down as DCS.

 

 

http://www.flugmuseum-messerschmitt.de/Me109G4/360Cockpit/

[NineLine]

I think the elevator trim bf-109 k4, remains bad modeled.

In this screenshot from 360º view of bf-109G4 of the Flugmuseum Messerschmitt, you can see that the normal elevator trim configutatión is -1 or negative (tail-down) not full nose down as DCS.

 

[/img]

 

http://www.flugmuseum-messerschmitt.de/Me109G4/360Cockpit/

 

You are basing that on parked aircraft? Maybe Yo-Yo asked the actual Luftwaffe pilot he was chatting with ;)

[Nooch]

Yes a parked aircraft has all it's electrical power off, of course, so the trim setting is not representative of the actual elevator position, which comes back to neutral.

[Echo38]

What you are changing is the horisontal stabiliser trim. Not the elevator trim. The whole thing, not trim tabs.

 

It seems in DCS we have trim tabs set to 0 deg.

 

I'm still a bit confused. Is the problem that you can't get the pitch to trim for hands-off level flight at max speed, by any method? Or is it that you can do this, but only by using a draggier method (namely, stabilizer trim) than you would use in a real 109 (which was tab-trimmed on the ground, to your specs)?

[Solty]

I'm still a bit confused. Is the problem that you can't get the pitch to trim for hands-off level flight at max speed, by any method? Or is it that you can do this, but only by using a draggier method (namely, stabilizer trim) than you would use in a real 109 (which was tab-trimmed on the ground, to your specs)?

You can't get the 109 to have nose down attitude at most power settings. The plane at neutral constantly goes up, and even fully trimmed down it goes up medium-high speeds.

 

It is apparent that elevator trim is set to neutral instead of beeing trimmed for level flight at cruising speed.

 

Yes a parked aircraft has all it's electrical power off, of course, so the trim setting is not representative of the actual elevator position, which comes back to neutral.

 

109 horisontal stab and elevator trim are operated by hand, no electric power needed.( ie. It won't go back to neutral without cranking the wheel with your muscles.)

Edited May 27, 2015 by Solty

[Nedum]

Wait wait.... all those posting to say that there is no problem and the germans are to dump to build a fighter with a good trim? So the DCS 109k trim is ok? Really? :glare:

Full nose down trim and the bird need a stick input to nose down for level flight and there are people who tell us that that is normal for one of the best WWII fighter planes? :huh:

If that is true, what alien build all those other weapons for the germans? :shocking:

[Echo38]

So we have Solty saying that the aircraft noses up at full power even with full down-trim, and we have Sithspawn saying that he can get it to fly hands-off level at full power. If I got that right, then either Solty is doing something wrong with the trimming part, or else Sithspawn is mistaken about the hands-off part. Which is it? Or did I misunderstand what one of you two was trying to say?

[Solty]

So we have Solty saying that the aircraft noses up at full power even with full down-trim, and we have Sithspawn saying that he can get it to fly hands-off level at full power. If I got that right, then either Solty is doing something wrong with the trimming part, or else Sithspawn is mistaken about the hands-off part. Which is it? Or did I misunderstand what one of you two was trying to say?

 

There is no way to make the plane fly with nose down attitude. The 109 just all the time pitches up. And even if it is possible to keep it somewhat level, it is still realy wierd that the plane tends to go up at higher speeds and you can't do a thing about it.

 

For example, during take off, I always trim it down max (+2). And the plane still pitches up and I have to push the stick not to have it flip on me.

 

IRL though it was mitigated by setting elevator trim tabs by the ground crew.

 

Question is, again. Why do I need 6 stages nose up, if the plane is so nose light at 0 trim, that it loops around itself?

[[DBS]TH0R]

Which speeds and what power settings? I find +1 nose trim more than sufficient for TO. Can't remember which setting I used for cruising but IIRC somewhere between +1 and +2 was enough for me.

 

Track, if you will, please.

[Echo38]

There is no way to make the plane fly with nose down attitude.

 

For my part, I don't particularly mind if I can't trim it to fly nose-down, but I do expect to be able to trim it to be level (hands-off) at full power and max level speed. (And, with my messed-up hands, I'd need to be able to do so.) Are you saying that this isn't possible?

[Solty]

Which speeds and what power settings? I find +1 nose trim more than sufficient for TO. Can't remember which setting I used for cruising but IIRC somewhere between +1 and +2 was enough for me.

 

Track, if you will, please.

I've checked it again. At around 450-470kph the plane starts to slightly nosing up and without correction via stick, the plane will procede to climb.

 

Because you want a track so much, here you are.

 

I am not pulling on a stick when the nose comes up from a dive, that is the plane doing it itself. 109 is trimmed to +2 in this track. You can check the stick movment via virtual stick hud ctrl+shift.

 

I only used the stick to keep the plane from rolling to the right, but no elevator input from me.

109 pitching up.rar

Edited May 27, 2015 by Solty

[[DBS]TH0R]

I like to see tracks to compare with my style of flying. Thanks, will check when I get home from work.

[NineLine]

I don't generally have a problem, if I trim to +2 my nose points down, even at full power/boost. Of course for cruising you generally wouldn't be flying around full power boost anyways...