UH-1H Bug Discovered

[nrk98]

I'm am sorry, in advance, if this isnt the right part of the forum to post this, but since i didnt find a UH-1H post in the english speaking part of this site, i'll just post it here.

 

This is the discovered bug, or if it really is a reality in itself, i dont know, i'll let you decide.

 

When i am about to takeoff into hover, the tourqe generated to make the helo hold still is quite impossible without a firm controlled grip on the cyclic, moving it very still and slowly.

 

Anywho, when in hover (about 10-12 feet above the ground), slowly moving forward, my Engine\Turbine and Rotor RPM is in operational mode, the helicopter suddenly falls like a rock, i crash and die. I see no decrease in engine and rotor RPM (N2) , and i do not even touch the collective, i have it in still position ( about 50 - 55 % throttle) and i still fall. Everything is perfectly normal and without notice, without any RPM warning signal.

 

When i notice i'm gonna start falling i, obviously, raise the collective to get more lift, but that dosent work either, im still falling like a rock.

 

It seems improbable to me that the helicopter is generating that low lift when it has operational standards, and i have my collective up. And it also seems improbable to me that a helicopter, this specific helicopter, that is in general a transport aircraft, can fall that easy without any warning whatsoever.

 

So thats why i'm turning to the Eagle Dynamics crew, and the forum, to try and figure out this irritating bug..

If anyone knows a fix, or similar, please do tell. The Huey is my favorite helicopter of all time, and i'd hate my experience of this magnificent helicopter, which is also made a damn nice and pretty, to be wasted by this little insignificant bug.

 

Thank you for your time, and thank you in advance for all support and advices i get, or may not get, after this is written.

 

Regards:

 

Roger

[TimeKilla]

Vortex ring it sounds like

 

http://en.wikipedia.org/wiki/Vortex_ring_state

 

Is that what's happening?

[BIGNEWY]

post a track file, its the easiest way to show the problem you are having :)

[nrk98]

Vortex ring it sounds like

 

http://en.wikipedia.org/wiki/Vortex_ring_state

 

Is that what's happening?

 

 

Damn, ive never even considered the vortex ring state... hmm.. but should that happen when you are actually acending up in the air ? I am moving away from my vortex state, so.. But that is perhaps why im crashing..

 

Damn, i should feel embarrased actually, me who is in heli flight school and all :P

 

Guess i got lots more to learn about aerodynamics :)

 

Thanks anyway :)

[Frusheen]

Roger that sounds like some interaction on your controls. You should be able to climb into a low ground effect hover and then without touching the collective transition into forward flight and climb away once your forward speed is high enough to increase lift. It is even possible to slow down and descend again from several hundred feet back into a ground effect hover without ever touching the collective from your initial lift off.

 

Check under options controls to ensure only one axis is assigned to your collective. Also ensure the throttle is properly set and governor is active before lift off (needles together in the green. If they split on lift off something is wrong)

[Flagrum]

Damn, ive never even considered the vortex ring state... hmm.. but should that happen when you are actually acending up in the air ? I am moving away from my vortex state, so.. But that is perhaps why im crashing..

 

Damn, i should feel embarrased actually, me who is in heli flight school and all :P

 

Guess i got lots more to learn about aerodynamics :)

 

Thanks anyway :)

As I understand VRS, you would have to be descending (too fast). But as I read your initial posting, I thought you were just at hovering at ground effect altitude and moving forward?

 

I am a more or less total aviation noob, but I can't imagine getting into VRS from 10-12 feet. The neccessary descent rate for that would make you already crash into the ground before you reach VRS...

[nrk98]

Roger that sounds like some interaction on your controls. You should be able to climb into a low ground effect hover and then without touching the collective transition into forward flight and climb away once your forward speed is high enough to increase lift. It is even possible to slow down and descend again from several hundred feet back into a ground effect hover without ever touching the collective from your initial lift off.

 

Check under options controls to ensure only one axis is assigned to your collective. Also ensure the throttle is properly set and governor is active before lift off (needles together in the green. If they split on lift off something is wrong)

 

 

Well yes obviously, but im falling without even touching the collective in any way. My Throttle and governor is properly set, and is in operational mode.

 

But i'm gonna go for vortext state, but that happening so often is fairly unlikely..

[Frusheen]

Check you don't have one of your cyclic axis assigned to collective as well. What you are experiencing doesn't happen unless you are giving way to much forward cyclic.

[genbrien]

is it not because when you're advancing, you're getting out of ground effect?

 

You should get some ''chop'' and a loss of altitude

[Rongor]

I doubt the vortex being the issue here. OP speaks of being in HIGE and then accelerating slowly.

[Robert1983NL]

Lol, is this thread serious? There's no bug nrk98. It's your flying. Just keep practicing :)

[Flagrum]

Lol, is this thread serious? There's no bug nrk98. It's your flying. Just keep practicing :)

Very helpfull ...

[Robert1983NL]

Yeah, what else is there to say? There's no bug that would cause what he is saying, other than a bug in the seat-to-stick interface.

 

Also, nrk98 isn't really clear on what the problem is. If he means what he says, I'd say 50-55% throttle is ofcourse not nearly enough to stay airborne. This should be 100%.

[nrk98]

Yeah, what else is there to say? There's no bug that would cause what he is saying, other than a bug in the seat-to-stick interface.

 

Also, nrk98 isn't really clear on what the problem is. If he means what he says, I'd say 50-55% throttle is ofcourse not nearly enough to stay airborne. This should be 100%.

 

 

Let me correct you on this. From ground takeoff, one should never ever just punch the collective up to 100 %, and it should never go to 100 % during flight either, because of the danger of RPM loss in the rotors + engine stress due to much resistance to the rotorblades, caused by the wind going between it.

 

And also, its not my flying, ive been flying helo sims since 06', and i consider myself to be a very experienced simpilot who understands basic aerodynamics, and also, im in Helicopter Flight School Norway.

 

Look, my problem here is that.. well, i stated this very closely in my main forum post, that you so generously is answering on. It might be the vortex state that is causing all this. I've been testing this phenomona for a while now on DCS, and i find it to be very likely.

 

Thank you for your consideration, people.

You have been very generous :)

[Robert1983NL]

Let me correct you on this. From ground takeoff, one should never ever just punch the collective up to 100 %, and it should never go to 100 % during flight either, because of the danger of RPM loss in the rotors + engine stress due to much resistance to the rotorblades, caused by the wind going between it.

NOW you're talking about collective. In your OP you were talking about 50-55% throttle.

And also, its not my flying, ive been flying helo sims since 06', and i consider myself to be a very experienced simpilot who understands basic aerodynamics, and also, im in Helicopter Flight School Norway.

 

Look, my problem here is that.. well, i stated this very closely in my main forum post, that you so generously is answering on. It might be the vortex state that is causing all this. I've been testing this phenomona for a while now on DCS, and i find it to be very likely.

 

Thank you for your consideration, people.

You have been very generous :)

 

Well... Then you haven't explained your problem very well, or you don't understand VRS, because you won't get VRS when you're hovering at 10-15 feet. You'd crash into the ground before you would be get anywhere near conditions that'd allow VRS...

 

Like I said, keep on practicing. It's the most realistic helicopter sim available on PC, way better than anything that was on the market before. Maybe that's why you're having a little bit of trouble.

[Paganus]

There is an easy way to test for a controller conflict.

 

Go to C:\Users\your user name\Saved Games\DCS\Config\Input\

 

Move the UH-1H folder to some other place on your computer for now.

 

Start the sim and go into options and setup just the most basic controls you need to test fly the Huey.

 

If the problem goes away there is something wrong in your setup. If it's the same then just put your old folder back since it's not the problem.

[nrk98]

NOW you're talking about collective. In your OP you were talking about 50-55% throttle.

 

 

Well... Then you haven't explained your problem very well, or you don't understand VRS, because you won't get VRS when you're hovering at 10-15 feet. You'd crash into the ground before you would be get anywhere near conditions that'd allow VRS...

 

Like I said, keep on practicing. It's the most realistic helicopter sim available on PC, way better than anything that was on the market before. Maybe that's why you're having a little bit of trouble.

 

Well then, would you mind telling us the cause of this problem ? You know, since you dont seem to belive what i think is causing this ?

 

And please, i do fully understand VRS.

 

Wikipedia: >Vortex Ring State< However, since the condition often occurs near the ground, lowering the collective may not be an option; a loss of altitude will occur proportional to the rate of descent developed before beginning the recovery. In some cases, vortex ring state is encountered and allowed to advance to the point that the pilot may lose cyclic authority due to the disrupted airflow. In these cases, the pilot's only recourse may be to enter an autorotation to break the rotor system free of its vortex ring state.

Edited May 25, 2013 by nrk98
Wiki

[ec-swr]

post track :music_whistling:

[Robert1983NL]

Well, you obviously don't understand VRS... But that doesn't matter, it's not the problem. I really think your flying hand is the problem. It's impossible to be in VRS while hovering in ground effect.

 

Well then, would you mind telling us the cause of this problem ? You know, since you dont seem to belive what i think is causing this ?

 

And please, i do fully understand VRS.

 

Wikipedia: >Vortex Ring State< However, since the condition often occurs near the ground, lowering the collective may not be an option; a loss of altitude will occur proportional to the rate of descent developed before beginning the recovery. In some cases, vortex ring state is encountered and allowed to advance to the point that the pilot may lose cyclic authority due to the disrupted airflow. In these cases, the pilot's only recourse may be to enter an autorotation to break the rotor system free of its vortex ring state.

[Vlerkies]

I'm am sorry, in advance, if this isnt the right part of the forum to post this, but since i didnt find a UH-1H post in the english speaking part of this site, i'll just post it here.

 

This is the discovered bug, or if it really is a reality in itself, i dont know, i'll let you decide.

 

When i am about to takeoff into hover, the tourqe generated to make the helo hold still is quite impossible without a firm controlled grip on the cyclic, moving it very still and slowly.

 

Anywho, when in hover (about 10-12 feet above the ground), slowly moving forward, my Engine\Turbine and Rotor RPM is in operational mode, the helicopter suddenly falls like a rock, i crash and die. I see no decrease in engine and rotor RPM (N2) , and i do not even touch the collective, i have it in still position ( about 50 - 55 % throttle) and i still fall. Everything is perfectly normal and without notice, without any RPM warning signal.

 

When i notice i'm gonna start falling i, obviously, raise the collective to get more lift, but that dosent work either, im still falling like a rock.

 

It seems improbable to me that the helicopter is generating that low lift when it has operational standards, and i have my collective up. And it also seems improbable to me that a helicopter, this specific helicopter, that is in general a transport aircraft, can fall that easy without any warning whatsoever.

 

So thats why i'm turning to the Eagle Dynamics crew, and the forum, to try and figure out this irritating bug..

If anyone knows a fix, or similar, please do tell. The Huey is my favorite helicopter of all time, and i'd hate my experience of this magnificent helicopter, which is also made a damn nice and pretty, to be wasted by this little insignificant bug.

 

Thank you for your time, and thank you in advance for all support and advices i get, or may not get, after this is written.

 

Regards:

 

Roger

 

 

Hi Roger

The quick an easy way to diagnose your problem is if you post a track on the forum.

To do this fly the huey so that it causes the issue you have, crash and burn :)

Then when you exit the game it will give you an option to save the track file.

Save it to a directory on your pc where you can easily locate it (desktop)

 

Then to post it on the forums, reply to this thread in advanced mode and you will have an option to upload a attachment, locate the track file you saved an upload it. Then we can run the track and see what is going on.

 

Regards

Edited May 25, 2013 by Vlerkies

[nrk98]

Well, you obviously don't understand VRS... But that doesn't matter, it's not the problem. I really think your flying hand is the problem. It's impossible to be in VRS while hovering in ground effect.

 

Let me quote again;

 

Wikipedia: >Vortex Ring State< However, since the condition often occurs near the ground, lowering the collective may not be an option; a loss of altitude will occur proportional to the rate of descent developed before beginning the recovery. In some cases, vortex ring state is encountered and allowed to advance to the point that the pilot may lose cyclic authority due to the disrupted airflow. In these cases, the pilot's only recourse may be to enter an autorotation to break the rotor system free of its vortex ring state.

 

Vlerkies;

 

Thank you for that explanation, i will do that right away :)

[71st_Mastiff]

The game engine is not that sophisticated to understand that your moving out of ground effect to calculate the probability of you being out of VRS.

 

In other words you are correct you have enough power to climb up and out.

 

So a trk for us to look at would show weather its input error, maybe cyclic settings?

I.E asymmetrical or symmetrical?

 

I had to put a curve on my cyclic to +5, to get out of VRS state, the reason for this is everyones set up or joystick is not the same and has sensitivity issues with DCS.

 

:pilotfly::joystick:

[TimeKilla]

You cant power out of a VRS once you're committed it will just make things worst as there is more down-wash being generated and you'll be pushed down into it, that's why you should power down if you have time and pitch if not just pitch.

 

I remember my first time, all you want to do it pull the collective up to generate more lift and that's you bye bye very interesting state.

 

But probley picked up you're comment wrong if so sorry buddy.

Edited May 25, 2013 by TimeKilla

[Robert1983NL]

nrk98, my knowledge of VRS is not limited to that of wikipedia. And I'll tell you once again: VRS can NOT occur when you're in ground effect. It's simply impossible. You might almost call it a contradiction! So yeah, it has nothing to do with VRS, unless you have a hard time estimating distances and a very unsteady control of the aircraft.

 

Let me teach you what wikipedia obviously didn't teach you. There are three prerequisites to get into VRS.

 

-An airspeed below ETL.

-A rate of descent exceeding 800fpm.

-A high AUM.

 

We all know that VRS is currently way too overmodeled in the Belsimtek Huey, BUT, it does not seem possible to me that you can get into a 800+fpm descent when you're at 10-15 feet, hovering. Unless you slam the collective down. But that means you crash because you lowered the collective, not because you entered VRS :)

Edited May 25, 2013 by Robert1983NL