Slower pitch trim possible?

[GregP]

Coming back to the Tomcat after quite a bit of time away, I was reminded of how frustrating it is to constantly be chasing the pitch trim around since the increment per button press seems way too coarse. There are solutions floating around here for several other aircraft that involve modifying the joystick default.lua file, but the F-14 is missing the relevant entries to do so. Has anyone come up with a solution to this over the past four years? 

[MAXsenna]

Coming back to the Tomcat after quite a bit of time away, I was reminded of how frustrating it is to constantly be chasing the pitch trim around since the increment per button press seems way too coarse. There are solutions floating around here for several other aircraft that involve modifying the joystick default.lua file, but the F-14 is missing the relevant entries to do so. Has anyone come up with a solution to this over the past four years? 

I wish all modules had a slider to adjust the speed of the trim like the free A-4E-C community module. Even the free MB-339 had it, can't remember if the paid one has it.

Cheers!

Sent from my MAR-LX1A using Tapatalk

[Tom Kazansky]

2 minutes ago, MAXsenna said:

I wish all modules had a slider to adjust the speed of the trim like the free A-4E-C community module. Even the free MB-339 had it, can't remember if the paid one has it.

Cheers!

Sent from my MAR-LX1A using Tapatalk
 

+1

[draconus]

3 hours ago, GregP said:

Has anyone come up with a solution to this over the past four years? 

They invented APs long before that but it's not an airliner to fly it hands free, trim is just to ease the force on the stick.

[GregP]

4 hours ago, draconus said:

They invented APs long before that but it's not an airliner to fly it hands free, trim is just to ease the force on the stick.

Sure, but presumably the designers of the Tomcat came up with a system that actually works as opposed to what we have in the sim at the moment. Why have a trim system if it doesn't actually allow you to trim out the stick force?

[draconus]

18 minutes ago, GregP said:

Why have a trim system if it doesn't actually allow you to trim out the stick force?

It does, you just have unrealistic expectations for what it should do, like keeping perfect level flight.

[GregP]

No, I'm not saying it should allow perfect hands off flight for a long period, I'm saying that it should at least allow a degree of control that does let you trim out stick forces such that you can take your hands off the controls for a few seconds, and have the plane maintain level flight during that time.

Are you suggesting that on the real aircraft, the trim function is not supposed to do this? Its function is to simply reduce stick forces without being able to easily eliminate them? If so, this operates different to pretty much every other aircraft in the world, I would think.
 

[GregP]

Also, we should acknowledge that level flight is only one condition in which a pilot may want to use trim. The point of a trim system is to allow the pilot to eliminate stick forces while holding any attitude they desire, obviously assuming that airspeed etc. remains constant. So the pitch trim system should allow me to hold a climb, descent, or level flight. I think it's confusing the issue to simply say that trim is not supposed to be autopilot; it's two different situations.

[draconus]

39 minutes ago, GregP said:

I'm saying that it should at least allow a degree of control that does let you trim out stick forces such that you can take your hands off the controls for a few seconds, and have the plane maintain level flight during that time.

But it does work in the Tomcat. If not, there's something wrong. Can you make a short video or save a track showing what's wrong?

[Bremspropeller]

1 hour ago, GregP said:

So the pitch trim system should allow me to hold a climb, descent, or level flight. I think it's confusing the issue to simply say that trim is not supposed to be autopilot; it's two different situations.

Are you accounting for the wings moving on a Mach schedule? Constant IAS climbs/ descends will make the wings move and that will get you divergently out of trim.

[Voyager]

Maybe a better question is, is this how the trim on the Tomcat worked? Are we getting the same degree of trim per press as the plane itself had, or is this an artifact of quantization in the sim? 

If that's how the trim itself worked on the F-14, we'll probably have to chalk it up to the quirks of a semi-analog plane. If that's not how the real trim worked, I see no reason not to modify it to better suit. It is a touchy plane to fly. 

[MAXsenna]

Are you accounting for the wings moving on a Mach schedule? Constant IAS climbs/ descends will make the wings move and that will get you divergently out of trim.

I don't think anyone is advocating for perfect AP like trim. But with the limited FOV we have on computers, it would be a nice feature to even trim it better.
If I let go of my steering wheel on the autobahn, I won't find myself in a ditch the next second.

Sent from my MAR-LX1A using Tapatalk

[Czar66]

14 hours ago, GregP said:

Coming back to the Tomcat after quite a bit of time away, I was reminded of how frustrating it is to constantly be chasing the pitch trim around since the increment per button press seems way too coarse. There are solutions floating around here for several other aircraft that involve modifying the joystick default.lua file, but the F-14 is missing the relevant entries to do so. Has anyone come up with a solution to this over the past four years? 

Flip the autopilot switch on to keep a fixed attitude and flipping back off will leave the trim at the current speed if manual trimming is that bad for your setup.

I'm currently flying the F14 everyday with the trim on a hatswitch and not even once the trim was bothersome... and I use and abuse the engines throughout several speed regimes in the same sortie. Wing sweep at auto or bomb mode, doesn't make any change on trim comfort for me.

I keep the hatswitch pressed for manual trim instead of several button presses. Maybe that's the source of your issue.

[Wavehopper]

Never had an issue with trim as it is, it holds level flight fine at all altitudes.

[GregP]

5 hours ago, Bremspropeller said:

Are you accounting for the wings moving on a Mach schedule? Constant IAS climbs/ descends will make the wings move and that will get you divergently out of trim.

The wings would move in this situation, why? That seems odd to me.
 

Either way though, the specific situation I'm trying to solve here is a constant airspeed level flight, so the wings most definitely would not be moving during that time and should not upset the balance at all.

3 hours ago, Voyager said:

Maybe a better question is, is this how the trim on the Tomcat worked? Are we getting the same degree of trim per press as the plane itself had, or is this an artifact of quantization in the sim? 

If that's how the trim itself worked on the F-14, we'll probably have to chalk it up to the quirks of a semi-analog plane. If that's not how the real trim worked, I see no reason not to modify it to better suit. It is a touchy plane to fly. 

This is exactly my point. I would imagine that in the real plane, the pitch trim has adequate sensitivity per press of the trim hat switch button, that it would be a fairly simple matter to completely trim out the stick forces during a constant air speed level flight situation.
 

But what I'm seeing on my end, across several different joysticks over the years, is that each press of the trim hat switch changes the trim position an amount that is larger than what I generally need, thus inducing a PIO type of situation.
 

On other aircraft, lua file changes have allowed us to, say, reduce the pitch trim increment by 50%, and It's been a great improvement. But it doesn't seem like such a change is possible with the F 14, at least upon my cursory look through some of the lua files. 

[Bremspropeller]

54 minutes ago, GregP said:

The wings would move in this situation, why? That seems odd to me.

Beacause a climb or descent at constant IAS will change your Mach and hence the wings will start moving, which in turn will upset your trim. Big and quick.

 

I personally like the coarse trim much better than the fine trim of two'ish years ago, when it took ages to retrim the jet after the wings moved about.

[Czar66]

3 hours ago, GregP said:

....

But what I'm seeing on my end, across several different joysticks over the years, is that each press of the trim hat switch changes the trim position an amount that is larger than what I generally need, thus inducing a PIO type of situation.
 

On other aircraft, lua file changes have allowed us to, say, reduce the pitch trim increment by 50%, and It's been a great improvement. But it doesn't seem like such a change is possible with the F 14, at least upon my cursory look through some of the lua files. 

If you're getting into PIO while trimming the current F-14, something is very wrong on your end.

Any chance you're expecting the Tomcat to act like FBW, 'hands off the stick' while level kind of comfort? Like the Warthog's CAS, hands always on the stick method is preferred, often with constant pressure for feedback. When on cruise, the auto pilot fixed attitude mode or level flight fills in the gaps if needed.

I can't imagine getting into an oscillation with the trim as it is besides the flights when I just got the module and was figuring out the wing sweep dynamics.

Go for a throttle setting first and let the plane settle at speed when in level flight before setting up a final trim because when the speed changes, the wings move. When the wings move the ideal trim changes and you have to set it up again.

[GregP]

37 minutes ago, Czar66 said:

If you're getting into PIO while trimming the current F-14, something is very wrong on your end.

Any chance you're expecting the Tomcat to act like FBW, 'hands off the stick' while level kind of comfort? Like the Warthog's CAS, hands always on the stick method is preferred, often with constant pressure for feedback. When on cruise, the auto pilot fixed attitude mode or level flight fills in the gaps if needed.

I can't imagine getting into an oscillation with the trim as it is besides the flights when I just got the module and was figuring out the wing sweep dynamics.

Go for a throttle setting first and let the plane settle at speed when in level flight before setting up a final trim because when the speed changes, the wings move. When the wings move the ideal trim changes and you have to set it up again.

Well PIO may have been an exaggeration; but my point was I feel like I'm constantly chasing the trim around - I get nearly stable with, say, slight back stick pressure required, so I do a single trim up press.  This then eventually puts me into a slight climb, so I try to cancel it out with a single trim down press - but this then puts me into a slight descent, so I try to cancel it out, and on and on and on.  It seems like I never get perfectly level without constantly needing to correct. 

And so yes, I realize this isn't a FBW aircraft, but from experience with other simulated aircraft, I highly suspect that if the trim increment was about half what it currently is, that single trim press would likely get me right where I'd want to be.

[Czar66]

2 hours ago, GregP said:

Well PIO may have been an exaggeration; but my point was I feel like I'm constantly chasing the trim around - I get nearly stable with, say, slight back stick pressure required, so I do a single trim up press.  This then eventually puts me into a slight climb, so I try to cancel it out with a single trim down press - but this then puts me into a slight descent, so I try to cancel it out, and on and on and on.  It seems like I never get perfectly level without constantly needing to correct. 

And so yes, I realize this isn't a FBW aircraft, but from experience with other simulated aircraft, I highly suspect that if the trim increment was about half what it currently is, that single trim press would likely get me right where I'd want to be.

I understand. Try the autopilot to get  the exact trim amount for the speed you're at. Just an ON and OFF action on it.

To fly level without slight descent or climb I usually keep pressure on the stick without trying to find a hands off trim setting because that's how I used to fly the A-10C and the MiG-21.

Fair skies.

[draconus]

7 hours ago, GregP said:

This then eventually puts me into a slight climb, so I try to cancel it out with a single trim down press...

I asked before for a video or track to make clear what is "slight" in your opinion. You see, some slight nose movement is ok, the air space is vast so you won't crash into anything in seconds. A few degrees after 10-20s is plenty to set something in the cockpit intermittently. Remember also that trim sets the aircraft for some airspeed and it will naturally keep it within that speed. Ever heard of a fugoid? If the nose move down a few degrees the speed will increase and the aircraft will raise the nose again a few degrees, then it will decrease speed, so the nose will go down again... Would you do it in NOE or in formation? No, but you should keep HOTAS then.

Some sim pilots count pixels of the nose against the horizon movement to keep perfect level flight but it does not work like that IRL. Part of the problem are mission creators setting 0 wind and 0 turbulence in the missions frequently.

Edited June 15, 2023 by draconus

[Germane]

vor 14 Stunden schrieb Voyager:

Maybe a better question is, is this how the trim on the Tomcat worked? Are we getting the same degree of trim per press as the plane itself had, or is this an artifact of quantization in the sim? 

If that's how the trim itself worked on the F-14, we'll probably have to chalk it up to the quirks of a semi-analog plane. If that's not how the real trim worked, I see no reason not to modify it to better suit. It is a touchy plane to fly. 

This is exactly the question! Maybe we can get an answer to that from @IronMike?

[Hiob]

19 hours ago, GregP said:

 So the pitch trim system should allow me to hold a climb, descent, or level flight. I think it's confusing the issue to simply say that trim is not supposed to be autopilot; it's two different situations.

But to hold a constant climb, you need an attitude hold AP mode. Trim alone can't achieve that. Given a constant thrust, the aircraft will settle to a constant altitude/speed after some oscillation.

btw.

I think IRL if a Tomcat driver needs hands free to do stuff, he or she would simply flip on AP Altitude hold and wouldn't bother with trimming. I believe AP is much more used IRL than we usually do in the simulation. Simple reason - real missions are longer and it would be very exhausting to fly manually the whole time.

Edited June 15, 2023 by Hiob

[IronMike]

2 hours ago, Germane said:

This is exactly the question! Maybe we can get an answer to that from @IronMike?

The trim has been set with extensive SME feedback, indeed. He's flown countless case 1s on speed (and much more ofc) - helping us fine tune the trim to the degree it is.

The Tomcat has a pitch up tendency during level, cruise flight, hence frequent trimming is required, but when you are slow and set on speed, little trimming should be needed once you are established.

Your hardware can affect this ofc, if the buttons are registering input, poorly. That would be noticeable though.

My personal experience is that in a stable, level flight with little to no acceleration, trimming it so that one can be hands off for a few seconds is no problem at all.

Additionally: you are not supposed to fly with trim, but hands on. Trim really is there to ease off the stick force you need, but keeping it level nicely, say within +/- 5 feet, requires a constant adjustment with stick input plus added trim as needed.

On top of that, you have a fighter's AP, which is precisely there to allow for hands-off operation when needed, unlike an Airliner's AP which serves to optimize the flight in various ways a pilot could not really achieve. In other words: engaging ATT HOLD or ALT HOLD in an orbit to prepare your cockpit for xy task, is completely legitimate. What you shouldnt do is fly a case 1 with autopilot ofc, etc.

A while ago a user had similar issues and I recorded this video, I hope it helps here, too.
 

 

Edited June 15, 2023 by IronMike

[IronMike]

1 hour ago, Hiob said:

But to hold a constant climb, you need an attitude hold AP mode. Trim alone can't achieve that. Given a constant thrust, the aircraft will settle to a constant altitude/speed after some oscillation.

 

In reply to this and the previous quote this was replying to: Not even, what you need to do is to hold your stick and adjust, aka work for it. Trim is not there to achieve a level, pitch up or down attitude, but to ease off stick force.

You can fly any attitude in the Tomcat hands on, and because it isn't FBW, it is actually more of a should than can. It is a hands-on aircraft through and through. Which is the beauty about it. Flying precision is demanding, and thus rewarding and fun. And having a RIO is presicely what allows you, the pilot, to fully concentrate on achieving just that.

[IronMike]

9 hours ago, GregP said:

Well PIO may have been an exaggeration; but my point was I feel like I'm constantly chasing the trim around - I get nearly stable with, say, slight back stick pressure required, so I do a single trim up press.  This then eventually puts me into a slight climb, so I try to cancel it out with a single trim down press - but this then puts me into a slight descent, so I try to cancel it out, and on and on and on.  It seems like I never get perfectly level without constantly needing to correct. 

And so yes, I realize this isn't a FBW aircraft, but from experience with other simulated aircraft, I highly suspect that if the trim increment was about half what it currently is, that single trim press would likely get me right where I'd want to be.

Unlikely, only like half of what you are seeing now, which would be still half of the climb and half of the descent you are chasing atm, because you are defacto abusing trim for something it was not meant for. If you watch the video above, trimming was done intermittently, but the main job is the hand working the stick, constantly. You have a huge body that provides an enormous amount of lift on the tomcat, variable wing sweep, a massive fighter which also provides quite some drag all around, so finding a sweetspot, as you try, is a fallacy in itself. You need to fight for it. And the moment you get complacent and stop, you pay for it dearly. In the beginning, especially when you are used to fbw aircraft or more stable sim modules, or flying with more AP and aircraft that also auto trim, it seems like a giant setback and nuisance. But after a while this will change. Not only will it train your muscle memory to be more fine tuned into flying level hands on (which is the far greater achievement than flying level hands off with aids), it will become more rewarding, flying itself will become a task to master, and once you master it, it will propell your skills in all other aircraft as well. My kind suggestion is: stop chasing the sweetspot that does not exist, start training your fine inputs and muscle memory, and profit long term, embrace it.