ETL Vibration

[Robert1983NL]

The part with accelerometers and not starting up to full RPM doesn't really sound like rotor track and balancing, sounds like more than that was wrong. And they're not tuned to have the least vibration at just the hover or cruise speed, they're tuned to have the least vibration at all speeds, you just work from the ground up to a certain speed, in that order.

[Focha]

Only one day for a track and balance?! That's a good day...

 

The last time we did balancing in Dauphin, after the 6 years maintenance, it took almost a week. It was just like you said, the first start run, we didn't get near flight detent, almost not even in ground idle, simply because the vibrations where so much that even the instruments were hard to read.

 

The maintenance guys, sometimes even said; "It's not possible!" :P Not good to hear from maintenance guys. :huh:

 

I think all of you already understand what I was trying to say, I don't bother about the ETL vibrations, but it bothers me that those vibrations seems to affect helicopter control, I'm not talking about normal changes in aerodynamics or performance, I am fully aware of that.

 

I have heard fellow pilots talk about vibration in Huey, but that does relate to the status of the aircraft and it's old age. We all agree that helicopters are vibrating beasts, those are, to some point, normal.

 

But in my humble opinion, something is wrong with ETL vibrations in this sim. Maybe not. Never flown a Huey, I just can speak on the types I fly.

 

Regards.

Edited June 6, 2013 by Focha
Spelling; Writting

[Focha]

The part with accelerometers and not starting up to full RPM doesn't really sound like rotor track and balancing, sounds like more than that was wrong. And they're not tuned to have the least vibration at just the hover or cruise speed, they're tuned to have the least vibration at all speeds, you just work from the ground up to a certain speed, in that order.

 

Depends. Sometimes to have better vibrations at a stage of flight you have to sacrifice other stages.

 

For example, we got good results in ground and hover, once we got in the air, 100 knots things started to get bad, at MCP level flight, around 130/140 knots, we got another type of vibrations, mainly vertical.

 

They tuned it, we got better results in MCP but the hover was worse.

 

What is done, is that you fine tune the vibrations until they are within limits, after that, you still can get the vibrations level lower, but sometimes it's not possible to get those lower and not sacrifice other values.

 

Today is easier to balance the blades, I can only imagine what was back in the days. For example EH-101 can do it with all electronic attached in the nose, it read backs all the blades and the software pinpoint what you need to do to each blade to get it done in less time.

 

Balancing can be a pain.

[thaisocom]

My friend flew UH-1H in our air force (Royal Thai Air Force) for more than 10 years. He said that ETL does not effect control of aircraft in real life. Yes, the vibration is there but it does not effect the aircraft control. I hope they will fix it in the final version. :joystick:

[Robert1983NL]

My friend flew UH-1H in our air force (Royal Thai Air Force) for more than 10 years. He said that ETL does not effect control of aircraft in real life. Yes, the vibration is there but it does not effect the aircraft control. I hope they will fix it in the final version. :joystick:

 

 

We all already agreed on that fact I think, but going through ETL definitly does have effect on the helicopter attitude.

[_Tigre_]

+1

 

Today I got to talk to my friend who currently flies on the 412 but in the past has made ​​the switch machine in the 206 and 212 and also confirm that the vibrations present on the Huey for how they are implemented are not at all realistic, that 'too violent and are also reflected on the commands with the loss of structure of the machine, which just does not happen in reality '.

 

She told me about many aspects that affect the speech such as the amount 'of cyclic applied, two-bladed rotor, etc ... ., But 'has always stressed the handling characteristics of the formula Huey that are very sweet and in many ways even simple, nothing to do with the sim .

 

Hopefully settle the issue with the next patch, and the rest 'still a Beta.

 

:thumbup:

[darkstar130]

I'd say it's pretty close, in my experience from an R-22. I think the rumbling is from the teeter hinge design when going through ETL. In a fully articulated setup like your dauphin, the vibrations from ETL are absorbed through the advancing and retreating of the blades and the greater flexibility of the blades themselves. There's nothing to really dampen that on a teeter hinge design save for the dissipation through the blades and the body of the aircraft.

 

just my 2 cents.

[EvilBivol-1]

There are two points of discussion that I see: 1 - the visual and audio effects of ETL transition vibrations; 2 - the effect (if any) the vibrations have on the FM.

 

We've demo'ed the Huey to quite a few actual helicopter pilots and most of them are really impressed to see the ETL transition vibration effects. That doesn't mean it's absolutely realistic (I personally feel the vibrations are overdone also), but that seeing and hearing the effects, even if more severe than in reality, provides the correct cues to the pilot about what the helicopter is doing, apparently more so than they get in other helicopter sims. I would say, just my opinion, that it is one of those situations where the PC sim needs to amplify the visual/audio feedback in order to compensate for the lack of physical feedback. However we are not beyond adjusting the vibration if there is enough reason for it. Again though, most pilots I've seen fly the sim live specifically liked the ETL feedback.

 

With that said, I'm a little confused about the idea that the vibrations themselves somehow affect control. I will check with the team, but I am fairly certain that the vibration effects are purely visual and audible and have no mathematical effect on the model. The control effects you are seeing are simply the FM as it transitions through ETL. In other words, if we disable the vibration effects as a cockpit animation argument, the FM will behave exactly the same as it does with the vibrations enabled. Now a different question is whether the ETL transition is accurate in the FM and this is still subject to tuning, so if you have something useful to contribute as data or resource, please do so.

[HuggyBear]

I've mentioned before, possibly on the tester boards, that the ETL effect presented in the sim is exaggerated, though for a very good reason.

 

In a Huey ETL gives you a nice solid shudder through the whole airframe (and your body), DCS can't transmit this so instead the dash vibrates more than IRL and in my opinion the overall impression of ETL is very nicely simulated.

 

It's important to know where ETL is and know where the edges are as it's a very good aid in setting up for a confined area with little power margin.

 

If you are on final, good rate of descent, good rate of closure, with near hover power set and riding the edge of the ETL 'burble' you're pretty well set up for your approach and can usually just cushion a little in the last few feet.

 

The control problems people are experiencing through ETL have nothing to do with the 'animation' of the vibrations and a lot to do with the aerodynamics of hovering vs. forward flight, and the different control positions required for each.

 

In the hover you'll need about two inches of left pedal (varies with UAW, DA) which is a lot more than in forward flight. If you don't get that left pedal forward as/before you drop through ETL the nose will suddenly yaw right and you'll most likely over-correct back to the left when you kick in a boot of left pedal to counter.

 

This little dance is very close to what happens IRL, the problem we have in the sim is a lack of feedback to let us know when the nose is beginning to yaw, also a lack of practice in many cases. :)

 

Real Huey pilots usually take a while before they learn to anticipate these effects and look as smooth as the guys in the movies or even the youtube vids.

 

Having said all that, please keep posting topics like this so we can discuss issues and either submit them to the devs, or at least explain why they might not change.

 

Hope that helped,

 

- Bear

[TimeKilla]

There are two points of discussion that I see: 1 - the visual and audio effects of ETL transition vibrations; 2 - the effect (if any) the vibrations have on the FM.

 

We've demo'ed the Huey to quite a few actual helicopter pilots and most of them are really impressed to see the ETL transition vibration effects. That doesn't mean it's absolutely realistic (I personally feel the vibrations are overdone also), but that seeing and hearing the effects, even if more severe than in reality, provides the correct cues to the pilot about what the helicopter is doing, apparently more so than they get in other helicopter sims. I would say, just my opinion, that it is one of those situations where the PC sim needs to amplify the visual/audio feedback in order to compensate for the lack of physical feedback.

 

Thanks for the reply EvilBivol, I hope it remains the way it is myself am getting a feeling some people are seeing more than there used to in a simulation and it's taking them out of there comfort zones. If it's close to what happens in real life then am very happy with that.

[159th_Falcon]

Just to be certain Bear, you are NOT saying that;

The transition trough ETL is exaggerated in the flight model itself.

 

But only in the effects it has on the airframe in terms of noise and vibrations?

[komemiute]

Time to use the Special tab in the option screen to add a Huey checkbox - ETL Vibration...

Even a slider a la P-51 assisted take off would work...

[TimeKilla]

Nah that would just lead to adding a tab for everything someone does not like this is a realistic simulation, So don't understand why anyone would want to remove it.

[Suchacz]

Sorry, but the problem might be that you are not handling her in the right way. I don't have any problem with that transition. I will add a video here later when I will have some time to make one.

[komemiute]

Nah that would just lead to adding a tab for everything someone does not like this is a realistic simulation, So don't understand why anyone would want to remove it.

 

Agree with your point of view, but then why there's that P51 one?:huh:

[tranquillity]

What some people might dislike about the "loss of control" or whatever, is probably just lag on an online server..

i absolutely trust the developers and especially their testers, that they try and give us an as accurate and well thought simulation of how the thing feels in real life as they can, for us ppl sitting infront of a screen.

personally I like the FM, it's challenging, but it is possible to get on top of it with practice, which I find awesome!

(I never flew a real helicopter though)

what I sometimes encountered on the virtual aerobatics server, is that when you fly and land alone, the ETL transitions is easier to do:

when performing it with other hueys around, it sometimes is harder to get a smooth transition to hover...

last time I observed that this must actually have been rubber banding; the heli was wabbling around quite a lot..so the problem is rather on the other helicopters dust effects, and probably passing-by plane's smoke effects and stuff like that...

not the actual flight model in my opinion:)

[HuggyBear]

Just to be certain Bear, you are NOT saying that;

The transition trough ETL is exaggerated in the flight model itself.

 

But only in the effects it has on the airframe in terms of noise and vibrations?

 

That's right, the instrument panel vibrates more than the real thing, but this is necessary due to the lack of additional vibration feedback.

 

The need to kick in quite a bit of left pedal as you pass below ETL is not exaggerated.

 

- Bear

[Suchacz]

The need to kick in quite a bit of left pedal as you pass below ETL is not exaggerated.

 

- Bear

Yes, one must note, that the tail rotor is also coming out of ETL and it is loosing part of its efficiency too.

[sorcer3r]

That's right, the instrument panel vibrates more than the real thing, but this is necessary due to the lack of additional vibration feedback.

 

The need to kick in quite a bit of left pedal as you pass below ETL is not exaggerated.

 

- Bear

 

Sometimes it seems that the whole Huey gets pushed aside about 2 meters (not just a yaw movement).

is this behavior also accurate?

Edited June 12, 2013 by sorcer3r

[fjacobsen]

Sometimes it seems that the whole Huey gets pushed aside about 2 meters (not just a yaw movement).

is this behavior also accurate?

 

As You come out of ETL and add left tailrotor, this will will cause translational Drift (not lift). This means that the tail rotor thrust will push You sideways.

 

Thats also why You need to hold the cyclic to the left during take off and hover.

[IonicRipper]

Pardon me if I'm late to the party but if I may add my opinion: I think the vibrations are just a little too intense... Not from a realism point of view (no personal experience with the Huey) but strictly in terms of gameplay. I find it hard to keep my focus on landing when it seems I'm getting my teeth rattled out once i come out of ETL. Hopefully it will be toned down just a tad on release (or perhaps before.)

[PeterP]

Here is a follow-up to this post:

http://forums.eagle.ru/showpost.php?p=1780451&postcount=21

 

He answered briefly to me :

The TL in the Huey 2 blade models is between 25-35 knots, and the vibration level in the Sim for my experience is too much. In the DCS uh1 the TL make vibration on the helicopter from high speed to low, but in the real the TL make vibration only when you are passing from low speed to high speed; only during take-off, not on landing.

 

As soon as possible I will make a video with the gopro hero (a cam) attached on my helmet for examine the ETL.

Some info: he has ~2000 Flighthours on the Huey, 300 of them with NVG and about 300 on war theatre.
Edited June 28, 2013 by PeterP

[pbishop]

I just got this module not long ago and did a search for something along these lines here, just wanted to say that the vibrations in game (the whole instrument panel shaking liking it was having a seizure) would lead me to ground that aircraft. I think there is a very exaggerated display when the chopper starts to shake, especially when you notice its only the instrument panel that is shaking independently of the chopper itself, something feels/looks/seems wrong. Just wondering if this is going to be adjusted in the future, thanks.

[jay43]

I just got this module not long ago and did a search for something along these lines here, just wanted to say that the vibrations in game (the whole instrument panel shaking liking it was having a seizure) would lead me to ground that aircraft. I think there is a very exaggerated display when the chopper starts to shake, especially when you notice its only the instrument panel that is shaking independently of the chopper itself, something feels/looks/seems wrong. Just wondering if this is going to be adjusted in the future, thanks.

 

 

Remember its still in beta phase at the moment so we are not on the final release yet.

[pbishop]

Remember its still in beta phase at the moment so we are not on the final release yet.

 

I know, just throwing it out there. If nobody ever said a word it would long be out of beta.