Uncontrolled Trim

[Rainmaker]

But of you have the trim motors deflecting the actual surface why would you need trim tabs to begin with? Are you sure you are not refering to some abnormal situation?

 

Well, the trim tabs are a backup system. I don't know for sure as I do not work the A-10. I am going to presume that the trim motors for the tabs are electrical. In the case of manual reversion where you are on a cable and pully system, the trim tabs would still work to trim the airplane. The main trim functions would no longer be of any use as they are tied to the hydraulic side of the house with the actuators. So with manual reversion in place and no use of the trim provided by the servos linked to the acuators, your only function to trim would be the tabs. Like I say, I don't know if this is correct...it's mearly a hypothetical answer based on what I know of different airframes and how there flight control systems kind of play into that.

 

 

EDIT: as I re read that paragraph you quoted I realised something; do I state correctly that the trim tabs on the elevator are only used in an emergency situation with loss of both hydraulic systems? Interesting...

Isnt it nice all the good discussions we can have because of a computer based sim! ;)

 

 

That is my presumption and what the manual is telling me as well. I am going to also presume that trimming the main surfaces will give you a lot better trim authority than using the tabs as well.

[effte]

The elevator artificial feel device is also the normal mode elevator trim. It changes the zero stick force elevator position when you are trimming. When hydraulics are lost, electro-mechanical actuators drive the trim tabs to provide trim.

 

I'm not sure (as in 'have it from an authoritative source') what happens with the artifical feel in case of hydraulics loss. I believe they will still be in the circuit, but be rendered completely insignificant compared to the aerodynamic loads. You'll be overpowering them with trim and then making the final adjustments using muscle power on the stick.

 

Aileron artifical feel and trim operate in the same way in normal mode. In manual reversion, the stick is connected directly to the trim tabs which will then act as servo tabs as described in my post above.

 

All from the A model dash one - a must read if you want to know the A-10 systems.

 

Cheers,

Fred

[WynnTTr]

One thing that I have noticed while trimming the DCS A-10 is that the trim inputs are excessive or "course".

 

One click of the trim button/switch results in quite an attitude change. The real aircraft that I have flown do not behave that way, and I have flown everything from piper cadets to corporate jets. One click of the trim button should result in much less movement.

 

Wondering if there is a way to fine-tune trim within the sim?

Have you flown the A-10C?

 

Not to belittle your experience but just because you've flown everything else except the aircraft in question doesn't mean that's not how it is for said aircraft. Until you do everything else is assumption.

[Chops]

Have you flown the A-10C?

 

Not to belittle your experience but just because you've flown everything else except the aircraft in question doesn't mean that's not how it is for said aircraft. Until you do everything else is assumption.

 

Really?? Wow, thanks for the deep and helpful observation.

 

The way trim works in the sim does not make sense from my perspective as a pilot. There is way to much movement around the lateral axis of the aircraft when using Nose-Up or Nose-Down trim. This makes it very difficult to get the aircraft stabilized, and sort of defeats the whole purpose.

 

This very well may be how trim works in the real A-10C, but it seems like a design flaw, especially since the airplane has such a rudimentary autopilot system. Of course, I would like to hear from an A-10C pilot regarding this issue.

 

Are other sim pilots experiencing this problem? I am wondering if it has something to do with my hardware setup, and if there is a way to adjust or fine-tune the trim within the sim?

[Bvoiash]

That's strange, as I have found the trim in A-10C to be able to make rather fine adjustments. What's the hardware setup that you are using by the way? And no, as far as I know there is no way to fine-tune the trim in this sim unfortunately.

[WynnTTr]

Really?? Wow, thanks for the deep and helpful observation.

 

The way trim works in the sim does not make sense from my perspective as a pilot. There is way to much movement around the lateral axis of the aircraft when using Nose-Up or Nose-Down trim. This makes it very difficult to get the aircraft stabilized, and sort of defeats the whole purpose.

 

This very well may be how trim works in the real A-10C, but it seems like a design flaw, especially since the airplane has such a rudimentary autopilot system. Of course, I would like to hear from an A-10C pilot regarding this issue.

 

Are other sim pilots experiencing this problem? I am wondering if it has something to do with my hardware setup, and if there is a way to adjust or fine-tune the trim within the sim?

Again you're assuming something. You experience is not the end all and be all and all your opinion is just that - opinion. Other pilots may well find it's spot on.

 

And if you want to be snarky, frankly I'd rather trust what ED with their consultations with relevant SME's (who HAVE flown the Hog) over your opinion.

 

Of course we won't know until we get confirmation from ED but until then to say that this is a "design flaw" is a bit presumptuous.

 

Question: what HOTAS you using?

[Inseckt]

I am also intrested in a answer to chops's question. I to experience the trim "Increments" to be at bit big. My desiered trim is regularly between two of these increments...

[WynnTTr]

I am also intrested in a answer to chops's question. I to experience the trim "Increments" to be at bit big. My desiered trim is regularly between two of these increments...

You using the TM:WH? Or another setup?

[Inseckt]

im using x52 with jackBauers profile, where the trim is on one of the povhats... (Saving for TMWH though:))

[Bvoiash]

When trimming, do you just tap the hat in certain direction Inseckt? Because the longer you hold the hat down in certain direction the larger the trim will be if the HOTAS is configured accordingly. Just wondering here.

Edited April 1, 2011 by Bvoiash

[WynnTTr]

im using x52 with jackBauers profile, where the trim is on one of the povhats... (Saving for TMWH though:))

Maybe it's a curve problem with the profile then? Because I'm using the WH and the trim does not feel over-exaggerated. It's just right in keeping the Hog stabilised with very minor pushes, like when I release ordnance it's only a couple of flicks to get me steady again. never had to compensate for overtrimming in one direction either. Like if I press nose down the aircraft doesn't lurch down suddenly.

There is absolutely no way I could "fly" the hog by just using trim.

[Krebs20]

I've only flown light twins and single engine trainers. Keep that in mind.

Electric trim in DCS seems to about spot on. In and Cherokee 160 you have the electric elevator trim or you have a wheel to trim. When flying the electric trim is great for take off and landings. When making constant speed changes. However, in cruise flight I always use the manual wheel trim. It is much more precise than the electronic button.

My example being, the best I've trimmed the 160 was about a 25 +/- feet per minute with electronic trim. With manual I can get the aircraft to fly hands off without any noticeable +/-. If the winds are forgiving. In flight you are always trimming. In fact in a small aircraft you will be trimming more often then changing your throttle. It's just something you always do.

In dcs A10 I'm always fighting the plane. It seems I'm +500 feet then -1000. At 1st I was much worse. Now its getting better with practice. Still have fits of 2-300 feet +/-. Remember your trimming to take pressure off your controls. Don't fly the plane with trim it it will won't work well. Fly with the yoke.

So next time you fighting a climb. Don't trim 1st. Push your yoke forward to stop the climb. Get it in level flight using your yoke. Then trim. If you trim 1st, you'll just Chase your VSI up and down.

 

I hope this helps some.

Edit..... I just read the other replies and they answered it already. I need to read more than the 1st post next time.

Edited April 1, 2011 by Krebs20
i read more.

[Inseckt]

Maybe it's a curve problem with the profile then? Because I'm using the WH and the trim does not feel over-exaggerated. It's just right in keeping the Hog stabilised with very minor pushes, like when I release ordnance it's only a couple of flicks to get me steady again. never had to compensate for overtrimming in one direction either. Like if I press nose down the aircraft doesn't lurch down suddenly.

There is absolutely no way I could "fly" the hog by just using trim.

 

Hei! The pov hats dont have curves, they act as buttons, perhaps this is the reason? I am aware that prolonged pushes will have a greater effect, but even my gentelest tap seem to have a certain increment. But its not THAT bad really, the precision im missing is only when refueling or formation flying, regular flight regimes trimming is mostly executed sucsefully... BTW, is the trim hat on the THWH functioning by axis?

[Bvoiash]

That hat set as buttons shouldn't be a problem if configured accordingly. As the hat that I'm using for trim has also been set up as buttons as well.

 

I suppose I could look into SFJackBauer's profile and see whether or not that is the source of the problem. As I think I should be able to at least open the profile with the Saitek profile software even though I own an X-65F myself.

[Frostiken]

I've used the trim in an F-15 (hey, it's closer than anyone else's comparisons :P) and it's not all that dissimilar from DCS A-10 from what I've seen. I think the difference is that in reality, trimming will actually move the stick so you have instant feedback, whereas in the videogame you basically just have to go off what the aircraft does. You can tap a trim switch in real life and feel that stick respond, whereas in the sim, well, you can't do that.

 

I've noticed that a completely minuscule tap of the trim hat will provide an appropriately minuscule trim adjustment. You have to be *very* delicate to get a perfect trim. What's nice about this is that there's no 'minimum' period for trimming like there typically are in other flight sims. The slightest tap registers and will have an effect.

 

On the A-10, the elevator tabs will act as trim tabs in manual reversion (lost hydraulics) mode, while the aileron tabs will act as servo tabs.

 

No trim tabs on the rudders, as they should normally never be out of center for normal flight. Lose an engine with unpowered rudders and you can expect to have one tired leg upon landing, and try to find a runway without too much of a crosswind.

That explains why my arm was tired after I got this home...

 

http://i.imgur.com/lcTPG.png

 

Trim would've been very helpful :D

Edited April 3, 2011 by Frostiken