Helicopter physics impressions - simplified

[maffa 29]

guys this is a bug, not matter how we lower arma expectations.

even if it were a candy crush like phone app this would be a bug.

[[frl]myke 14]

Lads, you can either discuss here what A3 is or what is it supposed to be and why it isn't and all that. Or you can file a report in the bugtracker and vote it up. Up to you.

[chrisb 196]

Its more or less all available in A2 at the moment, so I would think it will all come to A3 over time. Flying a heli as in TOH would be nice, but would have to be player choice, because its not that easy and would put some players off flying..;)

[iceman77 18]

I never heard the "ARMA IS NO SIMULATOR!!!" arguments before the release of ArmA III....Back then you would have gotten flamed to the ground if you had called ArmA anything else than a "Military Simulator". It even was on the box of the game...

And now? "Hey when my helicopter comes crashing down from 10.000 feet it suddenly activates some kind of anti-grav engines...". "AND? ARMA IS NO SIMULATOR!!!! IS PERFECT GAME! ALL HAIL BIS!!!".

As I said...

Whether or not BIS themselves labeled it as such doesn't make it a true simulator. Anyone can put labels on things. I will give you that infantry is simulated well (no weapon resting though). Or it used to be in any case. Too bad the game as a whole isn't just infantry. I'm not trying to make excuses for such behavior as seen with the helicopters either. That needs to be fixed. Obviously BIS would want things to work as intended, within their guidelines.

No one said the game was perfect, and no one was defending BIS, as I clearly stated. Infact... you're the only one who's typed those words here. Also, while I was into

, the truth hit me like a ton of bricks. Arma is a game with "simulator-esc" elements. It's a large scale, more "realistic", all around war game. If you want to pretend it's a simulator then by all means. Edited October 10, 2013 by Iceman77

[[frl]myke 14]

Simulator or not, at least A3 is clearly not a flightsim and shouldn't be treated like this. If this mentioned "slow crashing" is realistic or not, i can't say. I tried it in the editor and i found it rather interesting that the rotor kept spinning after the engine was turned off. Now i'm not a helicopter pilot so i don't know how much effect these spinning rotors have (if any at all) so i would like to hear the opinion of a actual real pilot about this. Personally i would expect complete destruction rather than safe landing but who knows.

Also myself i would welcome if BI would include the ToH flight model in ArmA 3 but that's not the topic here.

[maffa 29]

In chopper piloting there is something called autorotation, but it is a maneuvre that can hapen in certain circumstances depending in height speed and pilot traning (which we consider as a given in arma). It uses the chpper blades as a chute, keeping them rotating as the chopper descent produces an upward relative wind.

It could be either a bug, or a god-mode magic piloting "working as intended" procedure like the magic tab targeting pod or the magic healing procedure.

[relain 1]

Its more or less all available in A2 at the moment, so I would think it will all come to A3 over time. Flying a heli as in TOH would be nice, but would have to be player choice, because its not that easy and would put some players off flying..;)

Hi Chris,

this would be the perfect solution. Just a switch to "full realism" would enable the ToH Flightmodel. So every Admin could decide which skill level he want on the server.

PS:...Ehm....we all waiting for the KAI for ARMA3 or at least some updated video...*coughs :)

Back to topic:

I think what we see here in ARMA3 is a vanilla version of autorotation.

http://youtu.be/E2a9H8Xw8Mo

Edited October 10, 2013 by relain

[Azzur33 1]

The OP's test situation was with perfectly still chopper dropping straight down with autorotation, from blades that are already moving fast.

If you spawn yourself 1000 meters high without fuel and "none" instead of "flying", you'll start with the blades not moving, as you drop, they'll start to autorotate a bit, but not enough to save you, because the gravity and not having moving blades to keep you straight, have already tilted your chopper and you are dropping like a stone and the big boom is inevitable.

So, is this wrong or realistic? Seems ok.

[dharbert 0]

The OP's test situation was with perfectly still chopper dropping straight down with autorotation, from blades that are already moving fast.

If you spawn yourself 1000 meters high without fuel and "none" instead of "flying", you'll start with the blades not moving, as you drop, they'll start to autorotate a bit, but not enough to save you, because the gravity and not having moving blades to keep you straight, have already tilted your chopper and you are dropping like a stone and the big boom is inevitable.

So, is this wrong or realistic? Seems ok.

Auto-rotation is one thing, but in the test I performed, the helicopter dropped like a ton of bricks for the first 650 meters, then when it reached about 350 meters, some magical anti-gravity generator kicked in and GREATLY reduced the rate of descent to the point where you could tell even at that height that you weren't going to crash.

[JohnKalo 657]

What I would like to point out is that if Take On Helicopters flight models did get involved in this game it would be much more difficult for the Arma players to fly a helicopter.

They would need some serious training especially if you want a pilot to hover with no auto hover or auto-rotate to the ground after the chopper has accumulated too much damage or even target an enemy unit. Not to mention fast roping in harsh conditions, if it was possible. A lot of aspects would be employed which could even be appalling for some Arma players.

Also what about multiplayer? It would be a tragic condition if the pilot messed things up, let's say in the start-up procedure, and all the players on board were killed. The pilots would have to be chosen for their skills, something very difficult.

Maybe that is why TOH and Arma 3 weren't combined.

[maffa 29]

i surrendered to the fact that every ancillary aspect to infantry warfare is kept to a sketched status as best, in order to enhance the footmen experience. If seen in this respect, pilots will never do wrong as much as combat medics will never fail to revive an infantryman no matter the injury, or an AT soldier will never forget to take all the measures to fire his weapon properly (i.e. without killing everybody around him for a mishap). In the words of someone else that exposed this view, all activities that arent directly related to point your rifle and pull a trigger happens from the point of view of a grunt, i.e. they happen magically. Piloting, healing, paradropping, tank driving: it's all magical because it's not inherently pertinent to rifle shooting.

This said, autorotation is an emergency manoeuvre, not a parking technique. If you autorotate the frame needs to suffer some conquequence.

[Azzur33 1]

Auto-rotation is one thing, but in the test I performed, the helicopter dropped like a ton of bricks for the first 650 meters, then when it reached about 350 meters, some magical anti-gravity generator kicked in and GREATLY reduced the rate of descent to the point where you could tell even at that height that you weren't going to crash.

I didn't notice any Dramatic change in dropping speed. And it definitely is not because BIS somehow want to save chopper pilot.

Air density at 1000 meters is lower than nearer the ground. It affects the autorotation and descent speed.

[maffa 29]

LOL so does gravity

[Azzur33 1]

LOL so does gravity

Gravity does increase while descending and therefore affect the autorotation and descent speed?

[maffa 29]

Gravity affects the descent speed, moreso if -as the OP stated- that out of 1000m the first 650 were in full acceleration and the last were magically slowed down by some obscure force.

Air density at 350 that slow down a dull object in free fall, no, it doesnt work this way, not on this planet anyway.

If it's autorotation, the blades should never stop rotating from the moment the engine shut down. If the blade are still, they cant start rotating themselves fast enough to pull up the sheer weight of the chooper. If they were rotating fast enough, though, they can be kept rotating by the inclination the skilled pilot gives thru the collective, just as a trained fixed wing pilot can keep his plane gliding even if the engine shuts down balancing speed angle of attack and descent rate to avoid a stall. Unfortunately, air density cant stop bricks, choppers or airplanes from falling and crashing to the ground.

Edited October 10, 2013 by Maffa

[Ezcoo 47]

Gravity does increase while descending and therefore affect the autorotation and descent speed?

I'm not sure if you're talking about the situation in game or in real world, but at least in real world the gravity remains absolutely same in practice regardless of your position in airspace... Gravity is constant.

[dmarkwick 261]

Gravity is constant and air density is constant (certainly over ~1000m). My best guess for this mechanic is to give a cheap autorotation ability to AI.

[maffa 29]

ezcoo i think Azzur33 was sarcastically referring to my snap answer because he thought i thought gravity is lower to the ground, while i meant that gravity affects speed.

i didnt try this particular scenario yet, but if what the OP says is true, then if the blades are still, and you freefall from 1000 m, there is no reason on earth that you should dramatically slow down at 350m, because autorotation cannot kick in, no matter how skilled the pilot is. moreover, if the rotor blades are still moving because of the momentum the just stpped engine gave them, the ability to slow down the chopper is greater at the beginning of the manouvre, not at the end, because autorotation traning teach you to manage the blades' speed as long as possibile, i.e. to keep them from slowing down and stopping altogether.

[10t 12]

...Gravity is constant.

Well... (putting my pedantic and off-topic hats on) it depends how many decimal places you want to measure to. It doesn't "remain absolutely same" - F = G* (m1*m2)/(R^2). As you descend, you get (veeerrryyy slightly) closer to the planet's centre of mass, so R gets (veeerrryyy slightly) smaller, and so gravity gets (veeeerrrryyy slightly) stronger. Of course, it's difficult to measure - and for almost all practical purposes 9.81m/sec^2 is accurate enough over the altitude range most of us will ever care about. But I wouldn't be saying "absolutely same".

[Azzur33 1]

Gravity affects the descent speed, moreso if -as the OP stated- that out of 1000m the first 650 were in full acceleration and the last were magically slowed down by some obscure force.

Air density at 350 that slow down a dull object in free fall, no, it doesnt work this way, not on this planet anyway.

If it's autorotation, the blades should never stop rotating from the moment the engine shut down. If the blade are still, they cant start rotating themselves fast enough to pull up the sheer weight of the chooper. If they were rotating fast enough, though, they can be kept rotating by the inclination the skilled pilot gives thru the collective, just as a trained fixed wing pilot can keep his plane gliding even if the engine shuts down balancing speed angle of attack and descent rate to avoid a stall. Unfortunately, air density cant stop bricks, choppers or airplanes from falling and crashing to the ground.

I said: "Air density at 1000 meters is lower than nearer the ground. It affects the autorotation and descent speed."

Air density affects the blades, that is the idea. And Because helicopter blades do not stop rotating when the engine is shut down in Arma, it shouldn't drop like a brick either.

As I said before: If the blades are not moving at 1000 meters, you don't have any chance.

Engine shut, blades slow, chopper starts to drop, air friction keeps blades rotating, and slows the descent.

More air hits the blades, they rotate a bit faster.

And YES! "Gravity" was sarcasm!. And not because I thought Maf thought something, but just to get him to explain what he thought was worth of "LOL". :D

---------- Post added at 14:13 ---------- Previous post was at 14:06 ----------

but if what the OP says is true, then if the blades are still, and you freefall from 1000 m, there is no reason on earth that you should dramatically slow down at 350m

OP's blades were not still, he just shut the engine at 1000. It shouldn't drop like a brick to the ground, and it didn't. And there should be autorotation, which was there. And you can safely bring the chopper down with no damage, if you know how.

And if blades are stopped, or you stalled them, you go nose down to the ground without a chance.

So it works quite right in Arma.

Edited October 10, 2013 by Azzur33

[Ezcoo 47]

Well... (putting my pedantic and off-topic hats on) it depends how many decimal places you want to measure to. It doesn't "remain absolutely same" - F = G* (m1*m2)/(R^2). As you descend, you get (veeerrryyy slightly) closer to the planet's centre of mass, so R gets (veeerrryyy slightly) smaller, and so gravity gets (veeeerrrryyy slightly) stronger. Of course, it's difficult to measure - and for almost all practical purposes 9.81m/sec^2 is accurate enough over the altitude range most of us will ever care about. But I wouldn't be saying "absolutely same".

...that's why there is "in practice" in the previous sentence ;)

And YES! "Gravity" was sarcasm!. And not because I thought Maf thought something, but just to get him to explain what he thought was worth of "LOL". :D

Azzur33, I'm sorry, I see... :p Like my mother tongue teacher said, "sarcasm is an effective but very dangerous genre of humour" ;)

[mistyronin 1181]

Uhm, so... Arma 3 helicopters doesn't react 100% as in RL. Having in mind that its an action game, well not a surprise. Same way you don't have to arm missiles, and do all the protocols to fire one. It's just a piece of software that mimics a few real stuff with the main goal to have fun.

If you want a game that is close to helicopter simulation you can always play DCS Black Shark ( I do, an its awesome, you almost have all the cockpit functions ). But even that one is a simulator game, not a true simulator ( which you can find in the nearest helicopter pilots school ). And BTW not even that ones are 100% realistic, you know they are just a piece of software.

Conclusion if you want a an authentic helicopter experience, just fly a real one.

[maffa 29]

ok since i cannot edit any mission, i just started the transport heli showcase with the Orca. Climbed up to 1000 feet, Orca sprinted towards for no reason so i had to autohover, then when i hitted the 1000 feet i turned the engine off. It looked like it fell aprox 50-100 feet per sec, and the blades never stopped turning in what it looked like a controlled -parachuted descent. I also managed to keep some control in banking and if i tried to land i would probably managed to keep the damage i had by just letting it touch the ground as it were. At the end the chopper was considered destroyed, but truth be told it could have been repaired, and all the people on board came out on their feet.

All in all, it looked a crude representation of an autorotation, that if managed by the pilot could have prevented most of the damage.

If the blades stop turning, on the ther hand, you crash, as it is right it happens. i got this a lot during the attack chopper showcase where you may get hit by missiles that even though dont destroy your helo, they damage it to the point that the blades dont turn anymore and no matter how slow or low you were, the end is always a messy wreck.

This is what i can make out of it by just the means of showcase attempts.

[jiltedjock 10]

i surrendered to the fact that every ancillary aspect to infantry warfare is kept to a sketched status as best, in order to enhance the footmen experience. If seen in this respect, pilots will never do wrong as much as combat medics will never fail to revive an infantryman no matter the injury, or an AT soldier will never forget to take all the measures to fire his weapon properly (i.e. without killing everybody around him for a mishap). In the words of someone else that exposed this view, all activities that arent directly related to point your rifle and pull a trigger happens from the point of view of a grunt, i.e. they happen magically. Piloting, healing, paradropping, tank driving: it's all magical because it's not inherently pertinent to rifle shooting.

This is a very sensible way of looking at it, the game is full of approximations. This forum would have far fewer flame wars if the guys who think it is a sim would have a reality check and accept it for what it is - I am not talking about the OP, in the game an engine off descent from a 1000m should have more dire consequences than he described - I am talking about the guys who will argue over realism in vanilla and never mention the fact that AFVs might as well have a health bar over them.

Edited October 10, 2013 by jiltedjock

[maffa 29]

This is a very sensible way of looking at it, the game[/g] is full of approximations. This forum would have far fewer flame wars if the guys who think it is a sim would have a reality check and accept it for what it is - I am not talking about the OP, in the game an engine off descent from a 1000m should have more dire consequences than he described - I am talking about the guys who will argue over realism in vanilla and never mention the fact that AFVs might as well have a health bar over them.

yeah. If it werent for the fact that even shooting is lame, since ballistics and calibers and rifles are all over the place. But this is it, take or leave. I dont have the will to fight it anymore. I have A2 and have A3. I hoped the latter would be better -on every aspect- instead it's just different. And it's still a WIP, and there will be mods, and i still have A2+ACE, and many other games i liked to play before A2+ACE took all my gaming time. So we will live on.