2 helo issues/question

[Kaja 0]

All in all I have to say BIS did a good job on the OFP Helicopters, but there are some problems I have questions about. There are no coordinated turns for the helos (or simply, you can't roll them into a turn), leading to huge losses in air speed whenever you have to make a hard turn. Would fixing this and making the helos better able to side-slip be that difficult to patch?

Also high on my list, is the lack of emergency landings for the helos in game. The real helicopters depicted in OFP were designed for very heavy vertical crashes. However, the helos in OFP always seem to explode on touchdown in an engine out crash, pretty much regardless of how "soft" the landing was. Other than as a bug, I can't see much reason for it, am I missing something?

Thanks in advance.

[shadow 6]

I recomend you try with a joystick instead of the mouse

btw: choppers do loose airspeed when turning (yaw) in real life too.

As for the engine/crash-landing: we can't have it all I'm afraid

[Kaja 0]

I never fly with a mouse, I prefer to use my HOTAS joystick

I may be misunderstanding your reply, but turns at speed aren't accomplished with the anti-torque rotor, which is mostly used for turn coordination. In addition, while helicopters do loose airspeed in a turn (everything does), most don't loose upwards of 120 kph in a 90 degree turn.

[Harnu 0]

It all depends. In OFP, I can do a 90 degree turn and lose no speed. I can gain speed. Or if I want to I can lose speed. I just went playing around testing it out and it all depends on how you are turning. There are suddle differences in how to do it.

[NavyEEL 0]

yep you can make turns without losing speed. i think people try to turn around instantly which.... if you do that then of course you'll lose speed! lol as for always crashing with rotor failure, well you dont always die. yes the helo always explodes, but that usually happens in real life as well. ive survived many a rotor failure in ofp, crashing my helo and walking away with minor injures, but its rare. i think its as realistic as you can get without getting rid of the hit point damage system.

[Kermit 0]

That's not true. The problem is that, unlike in real life, you lose all flight control when your engine fails in Operation Flashpoint. In real life, if I ran out of fuel in a helicopter, I would be able to glide it down like a fixed wing aircraft to a rather bumpy landing. If I had any skill whatsoever with the controls, the helicopter should end up relatively undamaged (although quite jarred up), with the exception of the landing gear, and I should be mostly unhurt. A Cobra made a landing like this beside a highway near me; he experienced an engine failure at a decent altitude and glided it down to a safe landing. This is not an unusual occurence.

So the real problem is not the damage system. It is the flight model (that's a big surprise). If you are surviving crashes without ejecting, Navyeel, I think you are crashing into forests a lot, or possibly seriously lagging. The only time I survive an explosion is when I am lagging badly, and the only time my helicopter has an engine failure and does not explode is when it lands in a forest (it is a bug that cannot be relied upon).

[Kaja 0]

In response to the posts from NavyEEL and Harnu, I decided to do some testing with the AH-64 at the lovely Malden airport.

I found 2 things, Harnu is correct, you can certainly complete a turn without loosing airspeed. However, it's a really unnatural feeling, totally flat turn (even a little visual roll, if it did nothing else, would make it feel a lot more normal). Also, I apologize for exaggerating the speed loss in my initial reply.

Second, the hit point damage model seems to consider the damage of the helicopter more than the speed of the aircraft at impact .This can also be made very clear in game by ramming into trees at 200 kph with nary a scratch as a result (it's not as rare as you may think). At about 21 meters, a damaged helo is very likely going to explode after a crash. A healthy one, which has simply had it's engine turned off, will survive with only minor damage from a greater fall height. This may seem reasonable at first thought, but a proper autorotation can make an emergency, engine-out landing as soft as a normal one.

As to the "usually explodes in real life", I doubt it's likely to happen. Fuel/Ammo probably only explodes after a crash one would not have escaped from otherwise. Autorotations are much safer than most people think, I've been through a 180 auto (granted, intentional), and it was quite enjoyable.

[Kermit 0]

I have done many experiments with this this in Operation Flashpoint.  The damage of the helicopter does not matter.  If I turn off the engine at an altitude of five hundred meters, the controls of the aircraft cease to function (this is very unrealistic), and when I hit the ground, it explodes instantly every time.  The only exception is when I crash into a forest, in which case it bounces intact in the treetops.

I have never been able to figure out the relationship in Operation Flashpoint between helicopters and trees.  Sometimes a helicopter will brush the top of one going three meters per hour and explode instantly, and yet often when one hits a tree when going two hundred meters per hour it will merely bounce and hover there until you resume your flight.  It does not depend on the damage; I have done both many times with a fully intact helicopter.  My guess is that it has something to do with what part of the helicopter hits the tree.  That, at least, is quite realistic, if it is the case.

[Jinef 2]

i'm annoyed at how the rotors are not solid, you can easily have them going through a tree in OFP but that would not be good for your helicopter in real life.

they should simulate vortex effect in OFP, that would be great, you slow down to shoot at some tanks then you see and AA soldier so you yank the collective up, but for some reason you plummet towards earth. well the AA soldier missed but you are still dead

Auto rotations are fun If only they were modelled in OFP, i definitely think the aircrew should just be given pistols and the enemy should try and capture them instead of killing them as they are valuable. Instead of the death cutscene they should also have a captured one where you stick out your arms and they hit you with their rifle butts

[Johan_D 0]

As an FDE guy for PSS I all can say that the flight dynamics suck big time.

I didnt look into them deeply, but at first glance its awfull..

There can be add simply more realism in them easily.

Johan

[r71 0]

I guess its the game engine that does not allow for side slip. It would be a major plus if the choppers could move fast sideways like they can in real life. I post on this forum about it when the game first came out and never got a response from them. So they must not be able to do it.

[Kermit 0]

They can move sideways in Operation Flashpoint, but only if you are not moving forward or backward at all. From what I have seen in every other game with helicopters, I would say that this is realistic behavior.

[Spitfire 0]

I think that a crude autorotation IS modelled in OFP, though I've only managed to do it with the Apache.

The stick controls indeed do cease to function when you shut down the engine, but if you have enough altitude and manage to get the helo to descent with a big AoA (belly first, that is) the rotor starts to spin again giving the controls back - provided that you have lowered your collective. The rotor speed keeps up as long as you keep the collective down and keep a steady descent rate. Now you can easily cushion the landing and watch the rotor slow down in the process.

This behaviour is just like it's supposed to be in real life. Zero (or even negative) rotor blade angle with a deep descent rate and a high AoA gives the rotor extra kinetic energy which you can keep up during the descent.

The effect in OFP is indeed very crude. Sometimes the rotor starts the autorotation spin and sometimes it does not. However I think someone at BIS has actually tried to model autorotation in some form.

Try it out with the Apache.

[Jamesia 0]

I don't have a joystick...... but the last thing i recommend while flying anything in flashpoint is using the mouse. Its a terrible idea.

I always use the keyboard. And when Im using the keyboard i only ever fly with my left hand (using WASDQZ,) so that with my right hand i can be on the numpad keys looking at my beautiful vehicle from all angles.  

+ helicopters are the best thing there is in operation flashpoint.

[r71 0]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Kermit @ Dec. 08 2002,07:50)</td></tr><tr><td id="QUOTE">They can move sideways in Operation Flashpoint, but only if you are not moving forward or backward at all.  From what I have seen in every other game with helicopters, I would say that this is realistic behavior.<span id='postcolor'>

If you ever seen a chopper side slip in real life you would know what I mean. Choppers come no where close to it in OFP.

[_WTF_onslaught 0]

sort of offtopic..

It would be nice if the co-pilot (gunner) had the option to sieze the controls, giving u a chance to save the chopper.

It would also be comforting to see him sitting next to you in vehicles like the UH-60-MG rather than him doing the crew chiefs job on the MG, and a vacant seat next to you!

[r71 0]

I think they did that to cut down on the amount of AI that you have to use, and that you would have to fight for control of the chopper with someone else. Might be useful if only the copilot had view of the radar and maybe someone could script a missile jammer for him to use. That would help make him a necessity. It would also be nice to get a tone when someone locks on to you. Then you could give him a certain amount of jammers to use.

[Kermit 0]

I thank you, Spitfire. That was a very informative post. However, I must ask one question. Your post has put doubt in me about my perceived definition of collective. I thought that "lowering the collective" is the same as decreasing the power. If it isn't so, then what exactly is collective, and how do you lower it in Operation Flashpoint? Do you merely press the move down key or throttle down if you have a joystick?

I have never actually flown a helicopter in real life. My experience (I admit it is not too great) flying fixed winged aircraft is nothing to rely on. I have flown "hardcore" helicopter simulators like Longbow, but I have seen enough of helicopters flying in real life to believe that Longbow may not be all that realistic, by the way. You can easily fly in Longbow without ever touching the pedals. However, from what I have seen of helicopters taking off in real life, a real helicopter takes much work with the pedals, as well as control of other factors such as collective (whatever it is) and blade pitch (which, I believe, is controlled by moving the stick; am I correct?).

R71, you are probably right. I have not seen a helicopter side slip just like that.

[Spitfire 0]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Kermit @ Dec. 09 2002,12:50)</td></tr><tr><td id="QUOTE">I thank you, Spitfire.  That was a very informative post.  However, I must ask one question.  Your post has put doubt in me about my perceived definition of collective.  I thought that "lowering the collective" is the same as decreasing the power.  If it isn't so, then what exactly is collective, and how do you lower it in Operation Flashpoint?  Do you merely press the move down key or throttle down if you have a joystick?  <span id='postcolor'>

Collective controls the angles of the rotor blades, and the collective itself looks pretty much like a hand brake in cars. Pulling the collective causes the blades to "cut a bigger slice" of air, that is increasing the angle of attack between the blade and air, thus "increasing power" as you put it. Helicopter rotors spin with constant RPM which can be set by twisting the collective handle, but usually the RPM is set to max when in flight.

I have a joystick and a throttle, so pulling the throttle back is like pulling the collective and increasing blade pitch, causing the chopper to rise. Pulling the collective is Q with keyboard and lowering it is Z, but I seriously think that doing autorotation landing with the keyboard is quite hard

The cyclic, on the other hand, is the stick which controls the angle of the whole plate assembly in which every rotor blade connects to. In effect, it tilts the rotor in direction you push the stick. So, the collective controls the amount of vertical force component that the blades produce, and using the cyclic you can direct some of that force to other directions in the so that the total force will be divided between the vertical z-component and horizontal x- and y-components. The force exerted on the x- and y-components makes the chopper move horizontally.

What comes to your Longbow-experience, it simulates a fly-by-wire flight system which is normally on every modern gunship. Fly-by-wire in helicopters essentially try to keep the vertical force component steady regardless how you yank the cyclic, so you can pretty much control the altitude very precisely. Fly-by-wire also compensates for the torque effect which occurs when you pull the collective. Torque causes the chopper to spin to the opposite direction of the blade rotation, and without fly-by-wire system you have to compensate the movement by pressing the opposite pedal (usually the left pedal in American choppers where the rotor spins clockwise). Most commercial helicopters don't rely on fly-by-wire computer so that's the reason they require much pedal input while hovering.

I hope this clears it up.

[Kermit 0]

Again, I thank you. You are very helpful.

[shadow 6]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Spitfire @ Dec. 09 2002,13:34)</td></tr><tr><td id="QUOTE">Helicopter rotors spin with constant RPM which can be set by twisting the collective handle, but usually the RPM is set to max when in flight.<span id='postcolor'>

I'm just nitpicking here

Helicopters (atleast all military models I know of) don't fly at max rotor rpm. Actually they never do so unless in emergency(except when lifting off). The AH-64A and D-modell usually runs the turbines (engines for the rotors) at 80-85%. That way they got power-reserves if they need it. Running the turbines at 100% constantly wear the turbines out. One of the requirements for the Apache Longbow is to be able to run both turbines (engines) at 130% (absolute maximum) for 15 or 20 minutes before they burn out.

Also the rpm for both the rotor and engine-effect varies with the amount of collective the pilot applies aswell. The collective to a certain degree controls the "throttle" for the engines too (a fine tuning-throttle so to speak).

More collective=higher blade-angle=higher turbine-preassure~higher rotor-rpm (unless the chopper is climbing)

Less collective=lower blade-angle=lower turbine preassure~lower rotor-rpm (unless the chopper is loosing height ofcourse)

This is configurable in most modern choppers, but the "standard" for the AH-64D is : Full-collective= 100% engine-throttle.

I have never heard of a chopper that needs full collective to cruise

Approx just above half on the collective (60-65% on the collective, depending on weather, temperature and payload) and 85% engine-throttle is normal to keep a Longbow cruising without loosing height at cruise speed.

[furia 10]

My 2 cents here. I am a professional Airline Transport Pilot Helicopter. I have experience on RL Kiowa and Mi17 plus others not despicted on the game such Bell 412, 212 A-109....

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Helicopters (atleast all military models I know of) don't fly at max rotor rpm. Actually they never do so unless in emergency(except when lifting off)<span id='postcolor'> All Helicopters work on the most stable range of Rotor RPM that is about 100% (desiderable) allowing for minor variations (about 3 to 5 %) I think you are confusing Torque or N1 values with rotor RPM that must be about 100% even before lifting off and must be mantained at this value during most normal flight conditions.

About the loss speed while turning the effect modelled on the OFP helos is accurate but a bit exaggerated since most airframes would not easily handle the stress produced by a very very tight turn at high speed the way the game allows to handle it. Anyway it is a standar procedure for fast (military or emergency opeartions) to make a hard bank slip to create drag without gaining altitude in order to reduce speed although it is very unconfortable.

I have not flown the RL Apache or Blackhawk but I find the others nicelly modelled for a game that is not a flight sim. Actually I like much more the OFP kiowa than Flight Simulator 2002 Bell 206. This last may have more hard coded real data but makes its handling almost unrealistic. Neither me or my pilot colleagues like FS helo while most find funny and basically realistic the OFP kiowa (Not meaning parameters but basic maneuvering) with just one exception.

Cruising at high speed with OFP helos, if you lowered the collective (throtle ) and pull back cyclic control (Joystick) the helo response in not accurate. on any helo a collective control imput has a tremendous effect making it lose alttitude.

On the game this effect is not very notorius and helos tend to float too much for my taste.

Anyway I must say that OFP have a surpisingly well modelled helos for a sim that is not a flight sim oriented.

[shadow 6]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Furia @ Dec. 10 2002,11:55)</td></tr><tr><td id="QUOTE">All Helicopters work on the most stable range of Rotor RPM that is about 100% (desiderable) allowing for minor variations (about 3 to 5 %) I think you are confusing Torque or N1 values with rotor RPM that must be about 100% even before lifting off and must be mantained at this value during most normal flight conditions.<span id='postcolor'>

When I said 80-85% engine-power I meant 80-85% out of 100%. I considered 130% to be the absolute max for the Apache's engine (that's what the data-sheet says) , so 85% out of 100% would translate into 100% out of 130% so to speak. Atleast that's what I meant

Lots of percentages here

N1-value? that's the power measured directly on the turbine/engine-axial right?

If that's so, then alle these percentages are n1-values.

Does the "engine-throttle" vary slightly with the collective on the Kiowa aswell or is this exclusively with the Apache?

The reason the Apache works that way is like you said yourself: to keep the most stable rpm for the rotor (but you already knew that I guess)

[Spitfire 0]

As far as I'm aware of, N1-value is the gas generator speed of the turbine, and it has little to do with the final RPM of the rotor itself. N1-value is a good measure for the output power of the engine, which is directed to the rotor via transmission. Increasing rotor blade angle increases air resistance of the blade thus requiring more power from the turbine to keep the RPM at constant 100% of the desireable value.

It works pretty much the same way as the constant speed propellers of modern piston engine airplanes. In those, the power is measured bythe manifold pressure and not the RPM.

[PitViper 0]

the autoheight is a bit annoying.  you should be able to disable it so that you control the absolute altitude. BTW, I fly pretty well with the mouse