Flight Dynamics Feedback From Real Helicopter Pilots

[b101_uk 10]

First, I am not a pilot but I have been at the controls of helicopters a couple of times over the past 30 years, however it seems to me that that there is to much effective lift at minimum collective pitch

This is either because the helicopter it to light,

Gravity at ~9.81m/sec is not working correctly giving the correct mass,

Air is to dense at a standard atmospheric pressure and altitude,

The down thrust effect assigned to the main rotor at a given collective pitch is too high,

Next it’s the function of “load†i.e. fuel/payload/passengers etc. there seems to be insufficient effect of passenger weights vs. required collective pitch and cyclic deflections to initiate movement/change/etc. and thus the countering of torque, also there is the effect on control trim pre and post “loadâ€

e.g. you would expect there to be a change in required control trim between a lone pilot and then the addition of 3 passengers at an additional ~225kg distributed uniformly around the rotor CoG,

I.e. a change in the countering of torque to account for the extra power required for the extra collective pitch for lifting the extra weight.

a change in general cyclic deflection from the position countering the weight of the pilot in the ~10:30h position relative to the rotor CoG (cyclic deflected slightly to the ~04:30h position to support that pilot weight) to a more central cyclic deflection with 3 passengers or changes appropriate for single passenger in addition to the pilot in either the other front seat or any of the rear seats.

I am sure I do detect some change in the above but the effects are just to mute given the high proportion in weight a single ~75kg (+-25kg) person is relative to the MD500 like light helicopter, e.g. I am between~ 1/11th and ~1/16th of the MTW or between ~1/5th to ~1/7th OEW of MD500, or if you have ever driven a car which merely sits on 4 wheels you will have noticed a drastic change you feel between driving with just yourself and when you have 4 adult people in a car some ware between a Smart car and a basic Golf/ford Focus in total weight.

After all the carrying of that extra weight is reliant on the compressibility of air and power and not just the mere resting on 4 wheels!

But then what do I know. :rolleyes:

[nightsta1ker 10]

My response to that is: Amount of lift with collective input varies with model of helicopter. Flying the H269C/S300C requires much more control movement than an R22, just as one example. So, I would have to say, it's relative. Also, perhaps your control sensitivities are not set properly. Depending on the setup different users may experience different things.

---------- Post added at 11:46 PM ---------- Previous post was at 11:45 PM ----------

Then again, you could be completely right. Not something I noticed as being too unrealistic in my test flying though.

[ocramweb 0]

b101_uk < you can set the sensitivity of your controller for collective input to become very realistic

[RUBIX 10]

Has anyone noticed that vortex ring state (settling with power) seems to have an introduction in the last two updates? At 0 knots and a high descent rate, the helicopter becomes unstable and pitches, roles, and yaws. However, when I add more collective, the helicopter seems to recover itself without any forward airspeed; although this does take a little time.

[EagleEye-GER- 0]

Has anyone noticed that vortex ring state (settling with power) seems to have an introduction in the last two updates? At 0 knots and a high descent rate, the helicopter becomes unstable and pitches, roles, and yaws. However, when I add more collective, the helicopter seems to recover itself without any forward airspeed; although this does take a little time.

No haven`t noticed that yet. You know, recover from VR with giving collective shouldn`t work, AFAIK. I really hope that these effects and the FM for proper recover techniques make it in the final release.

[RUBIX 10]

;2015351']recover from VR with giving collective shouldn`t work

I was just introducing that as a problem with the recovery. The flight model needs to reflect a more developed vortex ring state if collective is added. And the proper solution would be to lower collective and fly into clean air (in any direction).

Test out the vortex ring state and post your thoughts. (I could just be hoping it is there, but it might not be).

Edited October 3, 2011 by RUBIX

[EagleEye-GER- 0]

I was just introducing that as a problem with the recovery.

Ah yeah, I thought about that after my reply. Youre the thread starter and a pilot in RL, I guess. So you know certainly how to recover.:)

I must admit that I rarely fly ToH, until I read in the changelog that FM was improved. I really don`t like the behavior of the light helicopter in some circumstances. I can`t master that thing near the ground. It may be my controller settings or something else, don`t know, though I don`t have these problems in DCS: Black Shark (I know, absolute different kind of helicopter...but). I would like to know how the FM calculations are done in ToH and/or what I do wrong.

[max power 21]

In OA, if you have a helicopter with a c of g close to the centre and your velocity vector is vertically downwards, funny things happen. YOu can really get into it if you're travelling at a high rate of speed in a dive, then dumping the collective and flaring hard. With the collective dumped, the helicopter starts to get really unstable and starts to squirrel around all over the place. I think this might have something to do with off-axis wind-vaning behaviour. At any rate, it seems like it wants to put the main rotor any way but upward.

[EagleEye-GER- 0]

In OA, if you have a helicopter with a c of g close to the centre and your velocity vector is vertically downwards, funny things happen. YOu can really get into it if you're travelling at a high rate of speed in a dive, then dumping the collective and flaring hard. With the collective dumped, the helicopter starts to get really unstable and starts to squirrel around all over the place. I think this might have something to do with off-axis wind-vaning behaviour. At any rate, it seems like it wants to put the main rotor any way but upward.

In Arma I can understand, that Heli FM is somewhat basic, because its an infantrie sim with support from vehicles, though I can`t for ToH.

Yesterday I did a vertical flight (no speed, just full collective) and at one point the heli beguns to pitch and to make some other weird things, but I was still in the air, almost the same altitude, without falling like a stone. All with zero speed. On Profi settings or what it`s like in english. :rolleyes:

Edited September 2, 2011 by EagleEye[GER]

[royaltyinexile 175]

;2015351']

make it in the final release.

Speaking to our producer (our biggest Helicopter nut!) we discussed the option of compiling a list of all the awesone new flight features that we've introduced, and also honestly evaluate aspects of simulation that (at release) we haven't been able to model to the level where we're happy to include them.

If you'd like to have some specifics answered (i.e "do you model ground effect"; "do you model vortex ring state"; "will you be supporting decepticons at release"), then you're more than welcome to ask; although, it goes without saying, we'll try to be as specific as we can, when the time comes.

That's something that's probably more appropriate for another thread, as I've been hijacking this one for long enough now. Thanks as always to you guys for posting valuable feedback.

Best,

RiE

[max power 21]

;2015914']In Arma I can understand' date=' that Heli FM is somewhat basic, because its an infantrie sim with support from vehicles, though I can`t for ToH.

Yesterday I did a vertical flight (no speed, just full collective) and at one point the heli beguns to pitch and to make some other weird things, but I was still in the air, almost the same altitude, without falling like a stone. All with zero speed. On Profi settings or what it`s like in english. :rolleyes:[/quote']

My point was that the abovementioned behaviour may not be a vortex ring simulation and may be a throwback to the OA simulation. I'm no saying that the TOH flight model is anything like the OA model, I'm just guess that maybe they have some behaviour from the OA model still in there. I of course, do not know. What rubix was describing with the unstable helicopter in a vertical descent sounds like, if I may hazard such an uneducated guess, a gimbal lock problem rather than simulated behaviour.

[EagleEye-GER- 0]

Hi RiE,

first thanks for youre answer. I dont think that you hijack this thread. We do appreciate when something comes from devs, of course.:)

If you'd like to have some specifics answered (i.e "do you model ground effect"; "do you model vortex ring state"; "will you be supporting decepticons at release"), then you're more than welcome to ask; although, it goes without saying, we'll try to be as specific as we can, when the time comes.

Why don`t jump in with specific informations when we discuss features like Autorotation and Vortex Ring? Can`t see a dev posting in that Autorotation thread nor when we discuss VR here. Otherwise when you cant be specific before all is set in stone, then it`s ok. Though, I sometimes have the feeling(just the feeling) that you (ToH devs) avoid to be more specific about the flight model and aerodynamic effects. The FAQ just stated that these effects will be there, nothing more. Or did I miss something?

What was the outcome of the discussion about "a list of all the awesome new flight features..."?

---------- Post added at 02:08 PM ---------- Previous post was at 02:02 PM ----------

My point was that the abovementioned behaviour may not be a vortex ring simulation and may be a throwback to the OA simulation. I'm no saying that the TOH flight model is anything like the OA model, I'm just guess that maybe they have some behaviour from the OA model still in there. I of course, do not know. What rubix was describing with the unstable helicopter in a vertical descent sounds like, if I may hazard such an uneducated guess, a gimbal lock problem rather than simulated behaviour.

Understood.:) I´m absoluteley with you`re thinking that some behavior is from OA model. I just cant express myself very well in english, because it`s not my mother language.

[mankyle 410]

RoyaltyinExile said

If you'd like to have some specifics answered (i.e "do you model ground effect"; "do you model vortex ring state"; "will you be supporting decepticons at release"), then you're more than welcome to ask; although, it goes without saying, we'll try to be as specific as we can, when the time comes.

That's something that's probably more appropriate for another thread, as I've been hijacking this one for long enough now. Thanks as always to you guys for posting valuable feedback.

Why BIS people are the best computer games developers in the world?

Easy Answer:

They are the company who listen to their community and try to enable their wishes. I'm for TOH, A3 and whatever they sell.

I'm hopelessly addicted to their products since 2006.

[Sundowner 11]

;2016542']Though' date=' I sometimes have the feeling(just the feeling) that you (ToH devs) avoid to be more specific about the flight model and aerodynamic effects. The FAQ just stated that these effects will be there, nothing more. Or did I miss something?[/quote']Like I wrote earlier - the devs are afraid of the simulation junkies crowd :D If they say there is something modeled, we WILL test it to extreemes, and post everything that is wrong with it.... it's just the way we do things. Devs just don't want to get a mile-long list of bugs, ommited features and errors so close to release date ;)

[Chris CDN 10]

Hi folks,

I haven't had much time to fly this summer but I've jumped back into the CP after a few months off. I think the FM is coming along nicely but I was looking for some input from some of the other helo guys.

Disclaimer: I'm not sure if these effects are as pronounced in real life as they are in the sim and I just don't notice it because the control inputs are muscle memory and slightly more intuitive due to the feel of the aircraft, but indulge me anyway.

I believe the modelled level of ground effect is too pronounced. I tried to do a few toe-ins on buildings and if I brought the disk over the building I was trying to land on it seemed that the helicopter would spring up in the air five or six feet. I didn't change any control inputs nor did I touch the skid against the building. I know that ground effect isn't that pronounced in real life, but I imagine from a coding perspective it would be tough to master. May I suggest backing off on the values for how much 'extra lift' the aircraft gets when in ground effect.

Also, I may not have my controls set up 100% the way I want them, but I still find bottoming out the collective doesn't bring the blades to zero pitch. I can't seem to get a decent 'tac decel' going on unless I start to slow the aircraft very far back.

Just a few minor points I'm looking for input on. Thoughts?

[ocramweb 0]

I am afraid I have to back you up on those! @Chris CDN

and if I am very happy for banking on tkoh ;)

I just hate that heli annoying banking behavior ....

[Chris CDN 10]

Here are two VERY quick videos I threw together to demonstrate the Ground Effect and flat pitch issues I've been having.

Apologies for the music, it's being replaced shortly.

[LeftSkidLow 1]

I absolutely agree Chris and it's funny because those are the same 2 things that bug me the most. I have to wonder if these issues are related to when they made the flight model "lighter" because people were complaining that they barely had any collective remaining by the time the skids left the ground (despite the fact that this is usually how it is in real life). Unfortunately, now my skids leave the ground with barely any collective and ground effect is grossly over exaggerated. I've never done an approach in real life and had ground effect come anywhere close to bumping me back into the air. It's hard to do a normal approach in-game because it feels like flat pitch is stuck collective scenario.

Edited September 24, 2011 by LeftSkidLow

[ocramweb 0]

Maybe it ll help (the devs), but regarding that ''flat pitch'' if you induce full collective up and down once or twice, it should get you out of it, it works for me when that annoying 'I don't want to go down no more' happens. Not very realistic,but it happened to me once IRL do.. but I had a huge Cumulonimbus not far above my blades ;)

PS:you should put those in the Community Issue Tracker...never knows

Edited September 24, 2011 by ocramweb
tkoh CIT

[CarlGustaffa 4]

but I had a huge Cumulonimbus not far above my blades ;)

Will the main rotor cancel the updrafts? :p

[ocramweb 0]

:depressed: avoid thunderstorm it's best.

yeah I wished it ... but it took its own time and I had to bank, was later informed of the uvv (Upward Vertical Velocity) of the sudden thunderstorms around more or less 40 (m/s) .... which explain the 4 000 ft/min my needle was suddenly positively pointing to... found it difficult to rapidly overcome! ;)

Edited September 24, 2011 by ocramweb
spoiled it

[Helmut Duregger 10]

Here are two VERY quick videos I threw together to demonstrate the Ground Effect and flat pitch issues I've been having.

Apologies for the music, it's being replaced shortly.

From the video it looks similar to what people have criticised in X-Plane for some time (don't know if it has been fixed now). If you approached an oilrig there, the helicopter would also suddenly climb, triggered by a single raycast it seemed. Quite annoying, and according to some, not the real experience.

Would be nice if the effect in the video could be lowered, maybe even controlled gradually by multiple raycasts.

Please improve the two behaviours pointed out in the videos, even if only in a patch.

EDIT: Or maybe make it a config option, if the current behaviour should remain available.

Edited September 24, 2011 by Helmut Duregger

[ocramweb 0]

It will be nice to see it in the TOH Community Issue Tracker

+1 on CIT see bellow \/

Edited September 29, 2011 by ocramweb
Toh issues tracker

[Chris CDN 10]

Added ground effect and flat pitch issues to CIT.

[nightsta1ker 10]

I really hope they get this stuff ironed out. They need to listen to the real pilots. They have championed realism since they announced this project, but I am worried they are catering more to the Arma crowd than the pilot/simulator crowd. I think the game will sell more copies if they listen to us than if they don't.