Is it possible to trim this aircraft to fly hands off

[truebrit]

This is my only ww2 aircraft so I'm not sure if this is how all ww2 era planes fly. It constantly pitches up or down, banks left or right. I will trim stable for a second or two then it pitches or rolls, it seems to need constant trimming and I don't dare move my hand of the stick.

[Nealius]

That's how all props, indeed all pre-FBW aircraft, are. Trim just gets you in the ballpark. You still have to manually keep it steady the entire time you're flying. 

[Diesel_Thunder]

I got pretty close last night and was hands off for a while. Seems easier trimming this bird than the Jug or Mustang, at least to me anyway.

 

I always get the rudder trim first to get rid of any slip, and then deal with pitch/roll trim to maintain level.

[Hornetjock]

That's why the pesky safety catches on the gear and flap handles are a nuisance. As soon as you go "heads in", she pitches up or down. I put the catches onto the keyboard with one key for each. Much easier.

[SkipCarey]

adjusted the elevator trim lua file tonite from 1 to .25 and -.25 and its great so far (hands off flying ).

[Sarge55]

12 minutes ago, SkipCarey said:

adjusted the elevator trim lua file tonite from 1 to .25 and -.25 and its great so far (hands off flying ).

I presume this gives you finer control.  What is the file location, if you don't mind?

[Nealius]

I searched the entire Mods/Mosquito directory for an elevator trim lua, or any trim lua at all, and there was none.

[jonsky7]

33 minutes ago, Nealius said:

I searched the entire Mods/Mosquito directory for an elevator trim lua, or any trim lua at all, and there was none.

 

If you go into the control binding .lua you can adjust the values for the trim

DCS World/Mods/aircraft/MosquitoFBMkVI\joystick\default.lua

and

DCS World/Mods/aircraft/MosquitoFBMkVI\keyboard\default.lua

Find this at line 506

 

-- Tail Trim Wheel --------------------------------------------------------------
{ cockpit_device_id = devices.CONTROLS, down = device_commands.Button_16, up = device_commands.Button_16, value_down = -1.0, value_up = 0.0, name = _("Trim Elevator Nose Up"),   category = _("Flight Control")},
{ cockpit_device_id = devices.CONTROLS, down = device_commands.Button_16, up = device_commands.Button_16, value_down = 1.0,  value_up = 0.0, name = _("Trim Elevator Nose Down"), category = _("Flight Control")},    

 

Change the "value down" value to whatever you like, lower number is slower movement. Or you can add more lines with different values, just change the "name" a bit so it shows up in the bindings menu

for example I added

 

-- Tail Trim Wheel --------------------------------------------------------------
{ cockpit_device_id = devices.CONTROLS, down = device_commands.Button_16, up = device_commands.Button_16, value_down = -0.25, value_up = 0.0, name = _("Trim Elevator Nose Up 1/4"),   category = _("Flight Control")},
{ cockpit_device_id = devices.CONTROLS, down = device_commands.Button_16, up = device_commands.Button_16, value_down = 0.25,  value_up = 0.0, name = _("Trim Elevator Nose Down 1/4"), category = _("Flight Control")},    

 

 

So using a modifier key you can have fast and slow trim wheel speed.

 

 

Edited September 19, 2021 by jonsky7

[truebrit]

 

Real pilot flying hands off while reading a map. Maybe he's using jonsky7's lua trick.

[BoNidle]

Nice one Jonsky7, works a treat.

[Dusty44]

I guess it’s as should be. This is the sea Mosquito but had the same engines. 

[Hiob]

Trimming is an act of balancing I guess.

Therefore it needs constant adjustments... and even if you find a trim, that is stable, it will only work with this exact set of external variables.

On top, the mosquito is very light weight and has very large surfaces, which would make it exceptional sensitive to winds and turbulences.

Having two engines instead of one, that pulls on the centerline, doesn't help either probably.

[Hiob]

On 9/19/2021 at 3:30 AM, truebrit said:

This is my only ww2 aircraft so I'm not sure if this is how all ww2 era planes fly.

At least, trimming works only for a given thrust and speed.

The Mustang can be trimmed quite reasonable (in all three axes), but as soon as you change the power, you need to adjust the trim.

From my pov this applies to all warbirds to a smaller or larger degree.

 

The way, that the trim controls are translated in dcs (incremental/digital instead of linear/analog) doesn't help, too.

 

[DD_Fenrir]

1 hour ago, Dusty44 said:

I guess it’s as should be. This is the sea Mosquito but had the same engines. 

 

Yeah..nah.

 

Same engines maybe. But the aircraft also had a tail hook and the necessary extra structural strengthening to absorb the loads on the rear fuselage, plus folding wings (=extra weight) and four bladed props.

 

Also this references a particular loading (1a) that pulls the CoG to 17.7ins aft of datum; without further information we cannot understand whether this loading is a representational operational payload bracket (likely but not explicit) or a purely testing loading to establish max/min limits for the CoG. We cannot then reference this against operational FB.VI loadings to see if there are any correlations.

 

As such, this Sea Mosquito information, as interesting as it is, is a red herring when referenced against an FB.VI.

 

Edited September 21, 2021 by DD_Fenrir

[Dusty44]

Ah ok, well if I find anything I will post it.

[scoobie]

Uhm... to straighten this up a little bit...

To the OP:
"Banks left/right" (or yaws left/right) - that's normal, just like others told you here. It's a good old "manual" plane, not an FBW spaceship. Don't worry - you'll get it and Mossie trims pretty nice.

But the pitch trim - if you're using joystick button commands for trim nose up/down and you find the Mosquito terribly sensitive - this is another issue, outside of the flight model, and the cure is to change the value in a Lua file as pointed above.
If you fix the pitch trim problem, bank/yaw trims should get easier - I imagine that currently you're easily pushing her out of pitch trim and that's why two other trims immediately go to hell.
Try the fix for pitch trim (start with 0.25 value, it's quite good), then see for yourself.

 

[pocketedition]

On 9/19/2021 at 6:32 PM, jonsky7 said:

 

If you go into the control binding .lua you can adjust the values for the trim

DCS World/Mods/aircraft/MosquitoFBMkVI\joystick\default.lua

and

DCS World/Mods/aircraft/MosquitoFBMkVI\keyboard\default.lua

Find this at line 506

 

-- Tail Trim Wheel --------------------------------------------------------------
{ cockpit_device_id = devices.CONTROLS, down = device_commands.Button_16, up = device_commands.Button_16, value_down = -1.0, value_up = 0.0, name = _("Trim Elevator Nose Up"),   category = _("Flight Control")},
{ cockpit_device_id = devices.CONTROLS, down = device_commands.Button_16, up = device_commands.Button_16, value_down = 1.0,  value_up = 0.0, name = _("Trim Elevator Nose Down"), category = _("Flight Control")},    

 

Change the "value down" value to whatever you like, lower number is slower movement. Or you can add more lines with different values, just change the "name" a bit so it shows up in the bindings menu

for example I added

 

-- Tail Trim Wheel --------------------------------------------------------------
{ cockpit_device_id = devices.CONTROLS, down = device_commands.Button_16, up = device_commands.Button_16, value_down = -0.25, value_up = 0.0, name = _("Trim Elevator Nose Up 1/4"),   category = _("Flight Control")},
{ cockpit_device_id = devices.CONTROLS, down = device_commands.Button_16, up = device_commands.Button_16, value_down = 0.25,  value_up = 0.0, name = _("Trim Elevator Nose Down 1/4"), category = _("Flight Control")},    

 

 

So using a modifier key you can have fast and slow trim wheel speed.

 

 

 

 

 

Genius, absolute genius.

Allows fine tuning of the pitch, a little touch up on the rudder control and you can fly to your hearts content.

Still gotta keep an eye on that aileron thing, that's maybe the prop torque doing that.

Genius. Just try it. I did, and what a difference.

Do you recall the difference the mod for slew control made to your HOTAS? This is up there with that.

Genius, although I'm not sure a human worked this out. This is some alien space technology here, this is magic, witchcraft.

How do people work these things out? Bloody genius.

jonsky7 good on ya. Genius.

 

try it, go on.

[jonsky7]

6 hours ago, pocketedition said:

 

 

Genius, absolute genius.

Allows fine tuning of the pitch, a little touch up on the rudder control and you can fly to your hearts content.

Still gotta keep an eye on that aileron thing, that's maybe the prop torque doing that.

Genius. Just try it. I did, and what a difference.

Do you recall the difference the mod for slew control made to your HOTAS? This is up there with that.

Genius, although I'm not sure a human worked this out. This is some alien space technology here, this is magic, witchcraft.

How do people work these things out? Bloody genius.

jonsky7 good on ya. Genius.

 

try it, go on.

 

You seem well pleased with that 

Your post alone made it well worth sharing lol  Thanks

[Lace]

Mine trims out ok. It seems to have a heavy port wing though. It’s worth noting -for those unaccustomed to props- that any trim setting is only correct for a particular speed, configuration and power setting.  Change any one of those and you need to re-trim.  IRL you trim the forces out of the stick.  Unless you have a FFB stick, this is harder to do in DCS, but I can still achieve a decent hands-off S&L. 

[Mike0f9]

I've found you can "trim" the pitch using the throttle(s) rather than the control tabs trim.  Get it close enough then if she starts descending add a touch of power - airspeed increases, lift increases and she'll come up.  Or vice-versa.  Sometimes it oscillates around a bit but if you leave things alone rather than constantly fiddle with the controls trying to chase it, she often settles down to neutral or close enough that you can safely mess around with the radios, maps etc.

[Lace]

2 hours ago, Mike0f9 said:

I've found you can "trim" the pitch using the throttle(s) rather than the control tabs trim.  Get it close enough then if she starts descending add a touch of power - airspeed increases, lift increases and she'll come up.  Or vice-versa.  Sometimes it oscillates around a bit but if you leave things alone rather than constantly fiddle with the controls trying to chase it, she often settles down to neutral or close enough that you can safely mess around with the radios, maps etc.

 

Trim sets speed, power sets altitude.  Think of the trim setting as a speed (or cruise control in your car).  You trim the a/c for 120kts, if you then add power the aircraft will try to maintain 120kts - and does this by beginning a 120kt climb, until it reaches an altitude where the new power setting is correct for S&L flight, and the aircraft settles into a 120kt cruise.  Now you reduce the power, the aircraft will again try to find 120kts, it does this by pitching down until you reach an altitude where again, the new power setting is correct for S&L flight.

 

What you are doing is not wrong, but you perhaps misunderstand (as many non-pilot simmers seem to do) what the trim is actually for and how it works.  If you trim for 120kts, and set power for 110kts then the aircraft will descend, and oscillate, eventually settling out at 120kts at a lower altitude.

 

The confusion comes as most people think (and fly as if) the power controls speed and pitch controls altitude, whereas this is not actually the case.

 

It is easy to demonstrate.  Simply trim the aircraft (any non-computerised FBW aircraft) for level flight, and open the throttles.  Does it get faster, or pitch up? 

[The LT]

 
 
Genius, absolute genius.
Allows fine tuning of the pitch, a little touch up on the rudder control and you can fly to your hearts content.
Still gotta keep an eye on that aileron thing, that's maybe the prop torque doing that.
Genius. Just try it. I did, and what a difference.
Do you recall the difference the mod for slew control made to your HOTAS? This is up there with that.
Genius, although I'm not sure a human worked this out. This is some alien space technology here, this is magic, witchcraft.
How do people work these things out? Bloody genius.
jonsky7 good on ya. Genius.
 
try it, go on.

JFYI, you can do the same trick with many other commands which rely on the "pressed" state. RPM adjustment, sight adjustment, etc. On all other dcs modules too.

[Hiob]

29 minutes ago, Lace said:

 

The confusion comes as most people think (and fly as if) the power controls speed and pitch controls altitude, whereas this is not actually the case.

 

It is easy to demonstrate.  Simply trim the aircraft (any non-computerised FBW aircraft) for level flight, and open the throttles.  Does it get faster, or pitch up? 

I'm aware of what point you want to make, and I don't want to reject it (I'm not a real pilot anyway, so what do I know) -

but I would argue, the answer to your question is "both" regardless.

 

To put it in a different perspective: Given a stable speed/altitude/attitude you can't go faster just by trimming. If you want to go faster and keep your FL and attitude you need to apply more thrust (and need to trim down to counter the according climb tendency)....

[Lace]

4 minutes ago, Hiob said:

I'm aware of what point you want to make, and I don't want to reject it (I'm not a real pilot anyway, so what do I know) -

but I would argue, the answer to your question is "both" regardless.

 

To put it in a different perspective: Given a stable speed/altitude/attitude you can't go faster just by trimming. If you want to go faster and keep your FL and attitude you need to apply more thrust (and need to trim down to counter the according climb tendency)....

 

No, the answer to my question is 'pitch up'.  The only way it would be 'get faster' is if you simultaneously apply forward stick (or trim) as you increase throttle.

 

Given a S&L trimmed aircraft, you can go faster just by trimming, but, as you stated, this will result in a corresponding pitch down, and then a settling S&L at a lower altitude and higher speed.  Trim effects speed.  If you want to increase speed and maintain altitude, then you will need a power increase.  Power effects altitude.

 

If you are interested in how this all actually works in reality it is worth booking a few lessons with your local flying school (even if you have no intentions of taking it further).  It will increase your understanding and help your simulator flying.

  

[Hiob]

@Lace

Still...

I get everything you said, except:

If you fly say 250 knots IAS at 5.000 feet, and you want to accelerate to 280 knots IAS and maintain 5.000 feet, how do you accomplish that?

 

I would suggest, open the throttle, counter the pitch up tendency with forward stick pressure and then trim out the forces.

If that is the wrong way, I'm really interested in the correct procedure! (no sarcasm! honest interest!)

 

Edit: I mean, I get it, you can easily switch my example above into:

Trim down and counter the altitude loss with throttle.

But that somehow is my point - don't you need always both? Really confused right now....

Edited September 29, 2021 by Hiob