Real life control trimming?

[Colstar]

Being new to the fly sim world I have only really just come across the term 'trimming' and assume it relates to flight sims and not real life aircraft. Is this correct?

[1lokos]

No, trim is feature of real planes, for allow pilot fly with need make pressure in control stick/yoke for keep a leveled flight.

Every time you change throttle, propeller pitch/RPM or speed, you need adjust trim for this new parameters.

In "flight games" they have a unreal (gamey) additional feature: "reset" trim.

In CloD all planes, e.g. Bf 109, Spitfire.. has trim like their real counterpart (minus the "reset"), but Fiat G.50 has trim in game not existent in real plane: for aileron and rudder.

[Baffin]

Being new to the fly sim world I have only really just come across the term 'trimming' and assume it relates to flight sims and not real life aircraft. Is this correct?

For information about trim, scroll down to page 3-10 of this document:

https://www.faa.gov/regulations_poli...05_afh_ch3.pdf

[Archwarder]

In my glider I have a trigger trim. When I squeeze it the trim instantly sets for the speed I'm flying.
Be nice if that was a feature on CLoD. ( Or am I missing something)

[69th_Zeb]

That's pretty cool Archwarder. I'm always weary of autotrim systems going runaway, but then I'm always aware of where that servo circuit breaker lives!

[ATAG_JackMaxx]

Baffin
thanks for link to flight manual, makes me sad to realise how little I Know and understand less. LOL

[Colstar]

Thanks for all the replies.

[ATAG_Scones]

No, trim is feature of real planes, for allow pilot fly with need make pressure in control stick/yoke for keep a leveled flight.

Every time you change throttle, propeller pitch/RPM or speed, you need adjust trim for this new parameters.

In "flight games" they have a unreal (gamey) additional feature: "reset" trim.

In CloD all planes, e.g. Bf 109, Spitfire.. has trim like their real counterpart (minus the "reset"), but Fiat G.50 has trim in game not existent in real plane: for aileron and rudder.

Thanks for the info.

May I ask why it was necessary to add the aileron and rudder trim for the G.50 to the game?

[1lokos]

When CLoD was released (in 2011) Italian planes are in very "Alpha" state - instrument panel don't work, engine start are a big lottery, and overall all planes FM, controls are generic, e.g. all have trim in 3 axes, etc.

Later - due players complains/pressure, the main planes like Bf 109, Spit... are fixed to their operation became more liked the real planes, e.g. trim only in proper axis.

But Italian planes - as in IRL BoB are secondary "actors" and leaved "as is", at time of release practically no one care about then.

[Archwarder]

That's pretty cool Archwarder. I'm always weary of autotrim systems going runaway, but then I'm always aware of where that servo circuit breaker lives!

Not sure about other aircraft but in gliders they are mechanical. Pretty sure it just adjusts the spring tension on the stick which adjusts its neutral point.

[69th_Zeb]

Glider trained pilots have that extra aeronautical edge over recip/jet only guys. I'm not sure if the RAF still does their initial flight instruction that way. Would love to fly one some day (probably tandem haha...too chicken now).

Given that airspeed indicators only run at a fraction of a psi or a few cm/H20 my assumption was that it had a pressure transducer, control board of some sort, and a servo. Gliders have all kinds of innovative stuff though, and I wouldn't be surprised if they came up with a mechanical solution. I've only worked on an old Schweizer and a Grob 109. The Grob had all kinds of weird innovative stuff I hadn't seen before, which goes right along with what you said.

(Sorry for the rabbit trail Colstar)

~S~

[RAF74_Buzzsaw]

When CLoD was released (in 2011) Italian planes are in very "Alpha" state - instrument panel don't work, engine start are a big lottery, and overall all planes FM, controls are generic, e.g. all have trim in 3 axes, etc.

Later - due players complains/pressure, the main planes like Bf 109, Spit... are fixed to their operation became more liked the real planes, e.g. trim only in proper axis.

But Italian planes - as in IRL BoB are secondary "actors" and leaved "as is", at time of release practically no one care about then.

I am sorry, but you are completely wrong.

There have been an enormous number of changes to the Italian aircraft, probably more than the German and British.

Nearly every single parameter line in the Fiat engine had to be changed... there were a large number of mods specifically created to allow the carburetors on the Italian aircraft to work, etc. etc. One obvious example, the operating rpms... the original game actually used the entire set of A-80RC-41 engine values used in the Fiat BR20 for the A-74RiC-38 in the G.50... complete nonsense... the 41 engine had 18 cylinders and 45 liters displacement compared to the 38's 14 cylinders and 31 liters displacement... One had a rpm limit of 2200, one had a rpm limit of 2520.

Nearly every single parameter in the aircraft flight model file also had to be changed... almost all the area measurements for control surfaces were wrong, weapons were wrong, etc. etc. etc.

There were hundreds of hours put into creating these changes, and for TF 5.0 there will also be many many changes to allow the virtual Fiat CR-42 to simulate the real aircraft, including re-writing code specifically to create damage modeling to replicate the type of construction design used in this aircraft.

There a still a few minor issues which need to be fixed in the G-50, i.e. aileron trim, will be done hopefully in the next 4.54 patch.

Anyone who takes the time to fly the original vanilla aircraft and then flys the current 4.53 version can see there is almost nothing which has not been changed.

[uranor]

Baffin
thanks for link to flight manual, makes me sad to realise how little I Know and understand less. LOL

The biggest issue with replicating trim control in any flight simulator is that there isn't any real force-feedback from the control surfaces. This makes it actually harder to trim the aircraft in a simulation than in real life. In a simulation, the only feedback you have is from the visual perception of pitch change (which, in real life is only used for minor trim adjustments). Do not be confused by so-called "force feedback" in joysticks; that is a nice feature, but has little to nothing in common with real world force-feedback.

CloD is better than most other simulators I have tried in reproducing the behavior of real-world airplanes, especially tailwheels. A LOT of work is being done to bring all the aircraft, and especially the Italian ones, which used to be less polished, to the highest standard allowed by the simulator. For that, thank the folks at Team Fusion who have been spending many sleepless nights working on flight models and researching the performance numbers.

[Disclaimer: I am a yet-unproven member of the team and claim no part in such feat].

[1lokos]

But Italian planes - as in IRL BoB are secondary "actors" and leaved "as is", at time of release practically no one care about then.

Nearly every single parameter in the aircraft flight model file also had to be changed... almost all the area measurements for control surfaces were wrong, weapons were wrong, etc. etc. etc.

Yes, but my reference was relative to released (2011) G.50 - that receive little care in the 2 years of MG patches and as you say "were wrong, etc. etc. etc."

And their wrong extra trims are legacy/testimony of this state.

[Baffin]

All "Force-Feedback" offers, is a system for tactile input to the pilot that something is happening in the sim. For example, the stick vibrates when the guns fire. I use a similar "Poor man's motion" via the Buttkicker Gamer device. It's lots of fun, but it ain't motion OR force feedback.

I suspect Uranor is referring to G-forces and stick pressures here, not force feedback. It's always the main problem with simulators that you can't "Feel" the airplane, and without mounting the simulator cockpit on a centrifuge, that will not change. If you're interested, here's one that claims to do just that:
http://www.nastarcenter.com/authenti...light-training


Since I think Uranor and I are saying the same thing in different ways, the following is for those trying to get a handle on trim for the first time...

TRIM "FEEL" requires no feedback from the control surfaces. The perception of trimming effect lies in the feel of the controller (Stick or Rudder Pedals) itself. Elevator trim, for example, only changes the back pressure required by your hand to maintain the desired elevator deflection. In trimmed level flight, for example, the stick requires no pressure at all, but the elevator is still deflected somewhat in order to maintain the desired trim airspeed. This is true of mechanical, hydraulic and servo-electric trim systems. All trim does is relieve the pressure on the stick by pushing the control surface a little by means of the trim tab. In hydraulic and purely servo-electric systems, all the stick does is open and close valves or switches... therefore, there is no natural feel at all in the stick. These airplanes must have synthetic "Feel" systems that provide pressure and centering feedback to the pilot, so it's just like the feel-spring generated pressures in your computer controller (Just a lot more sophisticated!).

Whether you are trimming a fast jet, a model airplane, or a flight simulator, the feel is essentially the same. It allows hands-off flight for straight and level flight or for a constant airspeed dependent control input, like a 250 mph climb. The only real difference between systems is the incremental change possible with the trim controller. In a purely mechanical system like a real Spitfire, the degree of fine trim control is limitless because you can move the analog control wheel "just a touch", while other systems require some sort of electric or hydraulic switch to activate the trim. Computer controls have a further constraint due to programming of the minimum possible input level. (i.e. one keypress = ⅔ degree, or whatever...). That's why it's hard to trim our CLoD airplanes "Hands Off" without high level programming like Thrustmaster TARGET and some others offer.

I have some experience in all trim systems, and it seems to me that CLoD trim works realistically if your controller permits fine enough input. The problem is usually with the controller or its software if the trim's not working correctly. The CLoD engine itself seems to be working par excellence in my opinion.

[uranor]

All "Force-Feedback" offers, is a system for tactile input to the pilot that something is happening in the sim. For example, the stick vibrates when the guns fire. I use a similar "Poor man's motion" via the Buttkicker Gamer device. It's lots of fun, but it ain't motion OR force feedback.

I suspect Uranor is referring to G-forces and stick pressures here, not force feedback. It's always the main problem with simulators that you can't "Feel" the airplane, and without mounting the simulator cockpit on a centrifuge, that will not change. If you're interested, here's one that claims to do just that:
http://www.nastarcenter.com/authenti...light-training


Since I think Uranor and I are saying the same thing in different ways, the following is for those trying to get a handle on trim for the first time...

Baffin, thanks for the correction. I used the term "force-feedback" poorly in this context. I should have said control pressures, i.e. forces exerted by aerodynamic loads on the control surfaces (unless one has fly-by-wire flight controls).

G-force (i.e. acceleration due to gravity and inertial forces) is an even bigger and more important difference between simulators and real airplanes, which you covered more than adequately.
On a side note, being also an Engineer, I tend to avoid the expression G-force, common among pilots, because the term induces confusion in beginning engineering students who have a tendency to confound real forces (thrust, drag, lift, gravity) and apparent ones (inertial). I prefer the expression "load factor" rather than G-force (which is perceived by some as a mystical Jedi influence exerted on airplanes).

~Uranor