Community Feedback Thread - TOH:CP

[b101_uk 10]

Anybody else getting the preview crash if -world=empty in startup command line? Consistent crash for me.

Me too as a test, but i don't use "-world=empty" normally.

As one of a small handful of KB/mouse-only users, I sometimes get worried if BIS is paying enough attention to controller-less development. In 84444, the new flight model is great, but flight with........etc.........etc.......etc

You "may" have to concede that maybe KB/mouse-only user may be better using medium or easy settings even if they used "hard/expert" in A2 etc.

There are many joysticks out there from the cheap to the expensive with many in-between, given the limited fidelity of KB/mouse-only ;)

[OMAC 254]

Yes, buying a controller may be a good idea for a top-quality game like ToH, but I am able to fly very well on Veteran/Expert in the ToH preview, as long as Freelook interaction is set to disabled (which makes it work as in A2 and earlier ToH betas). My brain is pre-configured to use Left Alt for Freelook anyway.

And difficulty setting has very little to do with real flying difficulty in the preview. I've been flying on Veteran and Expert since the first preview, and it is very, very similar to flying on Regular, it's just that hard landings aren't allowed, and a few other minor things.

I can successfully complete Ass&Trash on Veteran using 84444 preview. Try it if you haven't already - it rocks.

IMO, then, difficulty is not currently a problem, but I may have to prepare myself to buy a controller if BIS makes radical changes to ToH that make kb/mouse control unappealing, cumbersome, etc. It all works great now.

Edited September 12, 2011 by OMAC

[EagleEye-GER- 0]

I´m not sure about retreating blade stall in 84444. Shouldn`t the heli tilting over to the left side? Shouldn`t I feel when the stall is "building-up"?

[b101_uk 10]

;2022002']I´m not sure about retreating blade stall in 84444. Shouldn`t the heli tilting over to the left side? Shouldn`t I feel when the stall is "building-up"?

Yes, as the left is the retreating side, that also means the cyclic should bias to the right of centre #1 to stay level as you effectively have to increase blade pitch on the left and reduced it on the right advancing blades or you would roll left as speed built from a hover with the stick centre.

#1 assumes movement forward increasing speed from centre stick trimmed hover.

I did hit upon it I think it was in one of my latter posts in the autorotation thread of prior builds and came to the conclusion it is being applied but as a mirror image to what it should due to a left/right mix-up vs. forward or backwards movement, as for me forward movement is left stick bias and backwards movement is right stick bias.

[royaltyinexile 175]

I did hit upon it I think it was in one of my latter posts in the autorotation thread of prior builds and came to the conclusion it is being applied but as a mirror image to what it should due to a left/right mix-up vs. forward or backwards movement, as for me forward movement is left stick bias and backwards movement is right stick bias.

Well, I don't mind admitting that this is where my flight model knowledge ends.

I'll try to pass your evaluation along to a larger chopper-boffin.

Best,

RiE

[RUBIX 10]

In a rotating body such as a rotor disc (the disc created by the rotating blades), you must remember that gyroscopic precession (maximum deflection will occur ~90degs after force is applied to a spinning object) does play a major part in the dynamics of the rotor disc. In the retreating blade stall, the retreating blade has the lest amount of lift when it is straight out to the left (in a counter-clockwise rotor system); this is where the force is applied to the rotor disc, and the maximum deflection will occur ~90degs later when the retreating blade is in the aft position. What this means is that the disc will be tilted aft and produce a pitching up of the helicopter (not a left roll). I hopes this helps clear things up. I have not had a chance to test the 84444 flight model yet; I was just writing a response to the current conversation.

Edited September 14, 2011 by RUBIX

[max power 21]

I got my head bitten off by some helicopter pilot in the ArmA 1 forums a few years ago for suggesting that precession was a significant part of helicopter flight. He said that most of the stuff that had been theoretically accounted for by precession is actually to do more with the accelleration of the rotor blades.

[b101_uk 10]

Most of the uncommanded pitch up is actually an “engineered†precursor, as if you had excess forward cyclic authority to push threw at e.g.>> Vne near critical AoA you would actually end up much deeper into a roll based retreating blade stall as e.g. the left side runs out of lift wile the right is making plenty of lift, an uncommanded pitch up of the nose serves to slow and allows a reduction in blade pitch (AoA) thus taking the retreating blade/s out of stall so is better than being able to override any nose up pitch and it entering a roll/bank with limited and reducing options and a natural building of speed you don’t need.

I was not referring to “retreating blade stall†I was referring to the dissymmetry of lift which ultimately leads to “retreating blade stall†which is an end product so to speak, aspects of this (dissymmetry of lift) are being applied opposite left><right to direction of travel IMO given the side that the retreating/advancing blades are relative to direction of flight,

i.e. fly at set speed 40, 60, 80, 100kts using a centre stick hover trim, the stick (cyclic) bias moves left of centre when going forwards and goes right of centre when flying backwards, is that not opposite to how it should be applied given the cyclic’s effect on blade pitch/AoA as you move it left or right vs. the retreating/advancing blade side and there “effective†airspeed thus pitch/AoA needed on the right/left during normal flight?

If we then temper my statement above with the question of “flying sideways†left & right vs. what is the effective retreating/advancing blade position and its effective airspeed vs. cyclic position forward/rearwards of centre and the effect on blade pitch/AoA?

Then this reports correctly (as far as I can tell) if you start off with a centre stick hover trim, as flying sideways to the right the cyclic bias shifts rearward of centre favouring the retreating blades with increased pitch/AoA over the advancing blade, when flying sideways to the left the cyclic is bias shifts forward of centre favouring the then retreating blade with increased pitch/AoA over the then advancing blade.

As for specifically “retreating blade stall†in game its seems to have lost any uncommanded pitch up of the nose though has gained turbulence/shaking and if pushed through almost exclusively ends in a right roll/bank rather than a left roll/bank – that’s if you can trigger one at all even if well above Vne and well above >160kts or without initiating the nose up yourself, at lest prior iteration had the uncommanded element of pitch up as it drew plenty of comment from others ;)

Though all it could be I am just so ham-fisted! :D

[max power 21]

I read that disymmetry of lift should be taken care of via the flapping hinges (which all helicopters have in some form), since rolling moments can't be transmitted through hinges. I guess this would be true for fully articulated blades.

[RUBIX 10]

This conversation has sparked a lust for knowledge concerning the retreating blade stall topic. I have an open-ended research project this semester, and I believe I will focus on dissymmetry of lift, retreating blade stall, and gyroscopic precession. Thanks for the push for more knowledge. I hope to see you flying around after October 27th.

RUBIX

[max power 21]

The book that I'm referring to is called Military Helicopters from the Land Warfare: Brassey's New Battlefield Series. It's written for/by the Royal Military College of Science, blabbitybla bla bling and features an exam at the end, like all really great books do. In the book, IIRC, it explains that the primary limiting factor for the machine when a helicopter is approaching its Vne is excessive vibration. I don't know if tha's accurate for all helicopter types, and it was written in the late 80s. It does have some nice information on the fundamentals of helicopter flight with lots of diagrams, charts, and figures.

[RUBIX 10]

Thank you Max Power for the info. I will definitely give that a read.

[HuggyBear 10]

Retreating blade stall may cause left roll as well as pitch up.

I've felt it, didn't enjoy it. :)

The blade may stall well before the 9 o'clock position usually depicted in textbook explanations of RBS, especially when the high blade angle-of-attack is caused by inappropriate cyclic inputs and not just forward airspeed.

In my case a heavy UH-1H on a warm day, did not appreciate a rapid application of aft cyclic as I tried to enter a wingover to the right.

Following a very rapid-onset shudder through the airframe, the aircraft dropped quickly to the left and the cyclic was nearly yanked from my hand toward the left. This pretty much self-corrected my ham-fisted efforts and the whole thing was over in about a second.

A lot of aircraft will run out of power or shake themselves to death before the retreating blade can stall in forward flight.

-Bear

[EagleEye-GER- 0]

Thanks for youre input here HuggyBear.

A lot of aircraft will run out of power or shake themselves to death before the retreating blade can stall in forward flight

That is something I really miss also in ToH. Shaking of aircraft in various conditions. Yes, we have that mysterious shaking when speeding up, though thats all.

We do not have much feedback from the aircraft at all, is my impression. I`m not able to feel how the heli is doing. There are that flutter sound when you pull to much G´s or stress the blades, though haven`t heard much more then this yet.

Edited September 20, 2011 by EagleEye[GER]

[max power 21]

;2024905']Thanks for youre input here HuggyBear.

That is something I really miss also in ToH. Shaking of aircraft in various conditions. Yes' date=' we have that mysterious shaking when speeding up, though thats all.[/quote']

It is not mysterious. That is their indication of the vibration caused by the helicopter passing through effective transitional lift.

[DnA 5143]

It is not mysterious. That is their indication of the vibration caused by the helicopter passing through effective transitional lift.

Just to clarify: it will often seem that way because the vibration coincides with passing through ETL, however the shaking in CP is purely random. This heavy random shaking is gone in the full version, but we cannot easily port it back into CP. One place we added turbulence is when flying through the new volumetric clouds.

[max power 21]

Just to clarify: it will often seem that way because the vibration coincides with passing through ETL, however the shaking in CP is purely random. This heavy random shaking is gone in the full version, but we cannot easily port it back into CP. One place we added turbulence is when flying through the new volumetric clouds.

I stand corrected! I thought it was that way because of some observations made by forum members early in the CP. I'll do my best to stop spreading lies from now on!

[EagleEye-GER- 0]

I stand corrected! I thought it was that way because of some observations made by forum members early in the CP. I'll do my best to stop spreading lies from now on!

Don`t worry. ;)

I did used that word mysterious because no helicopter is shaking when passing through ETL, at least AFAIK and what others wrote.

Thanks DNA for clarification. Great to hear that it is not random anymore in full version.

[max power 21]

;2025423']Don`t worry. ;)

I did used that word mysterious because no helicopter is shaking when passing through ETL' date=' at least AFAIK and what others wrote.

Thanks DNA for clarification. Great to hear that it is not random anymore in full version.[/quote']

There is a vibration associated with ETL and with the transverse flow effect at low airspeed. I thought it was an exaggerated visual effect to indicate one of those two conditions.

[zentaos 10]

I hope that the HUD is not disabled in Expert mode in the final release. I think it's a valuable replacement for situational awareness.

Here's an example: say you're slinging a batch of Christmas trees on a logging site and you're leaning out the door looking down (or in the bubble if so equipped) as you approach the drop off to hit the box.

see this video:

you won't be looking at your guages to see your attitude. as a pilot you have "situational awareness" where you can feel minute movements, changes in pitch, balance, etc.

I think the HUD is a good replacement. It should follow where you look giving you a ball in circle attitude indication, ground speed, vertical speed, and direction.

my computer chair does not give me much feedback...

Edited September 27, 2011 by zentaos

[durg78 0]

I am not a pilot, so I may be wrong here and if so please correct me. I believe Torque-Induced Yaw is being simulated incorrectly. The way I understand it this effect should be tied to the throttle not the collective. The more throttle there is the faster the blades spin, which would cause right yaw and require left pedal to counter it. Changing the angle of the blades, which is what collective does, should not cause this.

Currently it seems this effect is tied to the collective. Also, my craft does not yaw to the right, it rolls or banks to the right.

[LeftSkidLow 1]

The throttle in most helicopters and all turbine helicopters is linked to a governor that attempts to keep the Rotor RPM at 100%. When you increase collective, drag on the main rotor system also increases, which should slow down the rotor RPM if it weren't for the governor. It's important to understand that in flight, rotor RPM changes very little, lift is primarily controlled by collectively changing the pitch of the blades, not the RPM of the rotors. So except for situations such as a governor failure or autorotation, collective changes will cause the aircraft to yaw.

[liquidpinky 11]

The throttle in most helicopters and all turbine helicopters is linked to a governor that attempts to keep the Rotor RPM at 100%. When you increase collective, drag on the main rotor system also increases, which should slow down the rotor RPM if it weren't for the governor. It's important to understand that in flight, rotor RPM changes very little, lift is primarily controlled by collectively changing the pitch of the blades, not the RPM of the rotors. So except for situations such as a governor failure or autorotation, collective changes will cause the aircraft to yaw.

Thanks, nice explination.

[durg78 0]

@LeftSkidLow, Thanks! That was a good explanation. So there should be some Torque-Induced Yaw when using the collective, but that doesn't explain why my craft rolls to the right. Any thoughts?

[colosseum 34]

Just would like to say thanks to BIS for being such a great developer -- I can't think of any other game studio that gives out a free toy like the MD-500 for us to play with like this.

I crashed a whole hell of a lot but I'm only a good pilot in ArmA, so...