Helicopter Help Needed

[Mick]

Does anyone here know anything about helicopter flight modeling?

David and I are working on a helicopter and neither of us knows anything about helicopter flight modeling.

Some years ago David made a Sikorsky R-4 and I think the flight model came from the stock Robinson R-22, which would be reasonably close for a small piston single. Now we're working on a large piston twin, a Sikorsky S-56 aka HR2S "Deuce" aka H-37 Mojave. As far as we can tell it's the first piston twin helo for FS9, so there is nothing we can borrow or steal a flight model from. Yes, we know there have been a couple FS models of piston twin helos, but under the skin they are turboshafts in disguise. We want a real piston powerplant. Anyway, it's not the powerplant we're befuddled by, it's the way the helo flies.

David started with an adaptation of the R-22 flight model. It didn't fly very well, certainly nothing like an S-56, but it allowed the model to load in FS9 so we could work on it. I adapted the AlphaSims Sikorsky S-55 (aka HRS aka H-19) but the result is no better. The helicopter flies, but not at all well. There are a couple of major issues that we haven't a clue to solve.

We have thrown up our hands and accepted the fact that this is beyond our ken. So we are desperately seeking a collaborator who knows more than we do, who might be able to get our chopper to straighten up and fly right.

Any volunteers?

[normb]

Geez Mick....we're all peeking but not responding!

My two cents: I suppose I would use a stable turbine model to get it flying and then convert it to recip following the some outline config/airfiles like Piglet's Hiller or Baldy's bigger helos. Lasse Lindh had some bigger recip birds too that might be cloned.

Baldy comes to mind as the guy who could really do this.

Norm

[Motormouse]

How about the air file from Alphasim/Virtavia Merlin as a starting point,?

S55 probably didnt work as its rotor and footprint are smaller?

Ttfn

Pete

[Bushi]

Does anyone here know anything about helicopter flight modeling?

David and I are working on a helicopter and neither of us knows anything about helicopter flight modeling.

Some years ago David made a Sikorsky R-4 and I think the flight model came from the stock Robinson R-22, which would be reasonably close for a small piston single. Now we're working on a large piston twin, a Sikorsky S-56 aka HR2S "Deuce" aka H-37 Mojave. As far as we can tell it's the first piston twin helo for FS9, so there is nothing we can borrow or steal a flight model from. Yes, we know there have been a couple FS models of piston twin helos, but under the skin they are turboshafts in disguise. We want a real piston powerplant. Anyway, it's not the powerplant we're befuddled by, it's the way the helo flies.

David started with an adaptation of the R-22 flight model. It didn't fly very well, certainly nothing like an S-56, but it allowed the model to load in FS9 so we could work on it. I adapted the AlphaSims Sikorsky S-55 (aka HRS aka H-19) but the result is no better. The helicopter flies, but not at all well. There are a couple of major issues that we haven't a clue to solve.

We have thrown up our hands and accepted the fact that this is beyond our ken. So we are desperately seeking a collaborator who knows more than we do, who might be able to get our chopper to straighten up and fly right.

Any volunteers?

I have no idea where I got this Wessex from! might have been alphasim, but it's been so long, and I don't have a read me for documentation. BUT it's a big sluggish, heavy bird that's quite stable in flight.. and responds well to the controls. YES it's turbine, but as far as airframe goes.. old, big.. heavy, tail dragger... the flight dynamics might be pleasingly similar to the machine you are creating.

Using it's air and cfg files might get you a good base to work from.
Dave

[Mick]

Well, one thing I tried was adapting the flight models from a couple different turboshaft helicopters, and with the piston engine sections patched in along with the other usual sections, they just crashed the sim. I have a couple other thoughts along those lines that I plan to try just in case they might work, but I really don't expect a better result.

The thing is, there aren't many real piston helicopter models. Most models of piston helicopters actually have turboshaft powerplant flight models, and one that I looked at actually has turbojet power. If one could successfully adapt a turbine flight model to a model of a piston helicopter, piston engine instrument gauges wouldn't work and turbine instruments wouldn't be appropriate. The few piston helo models I've checked out get around that by just not having much in the way of engine instruments. That looks OK on the tiny panel of, say, a Bell 47, where there are just a handful of instruments and only a couple engine instruments, but the big, wide S-56 panels are chock full of engine instruments that would look mighty strange if they all didn't work. All of that is moot as long as turbine flight models with this 3D model crash the sim. (I have no idea why that happens!)

With a piston flight model adapted from the AlphaSims S-55 the model has a very strong right turning tendency. The S-55'ds panel includes a rotor trim gauge that allows one to trim out a left turning tendency but sadly, not a right turning tendency. It also has an extreme forward (downward) pitch in forward flight. I've noticed that some other helicopter models (I haven't flown very many) also seem to exaggerate a helicopter's need to "lean" into the direction of flight, but in this case it's extremely exaggerated, with the nose pointed almost straight down at forward speeds well below the S-56's cruising speed.

I will continue to experiment but I am rapidly running out of ideas, as is David. Helicopters are far outside of our comfort zone and even further outside our areas of expertise. We are blundering along in the dark and we'd really like to hook up with someone who actually knows what they're doing.

[Bushi]

Well, one thing I tried was adapting the flight models from a couple different turboshaft helicopters, and with the piston engine sections patched in along with the other usual sections, they just crashed the sim. I have a couple other thoughts along those lines that I plan to try just in case they might work, but I really don't expect a better result.

The thing is, there aren't many real piston helicopter models. Most models of piston helicopters actually have turboshaft powerplant flight models, and one that I looked at actually has turbojet power. If one could successfully adapt a turbine flight model to a model of a piston helicopter, piston engine instrument gauges wouldn't work and turbine instruments wouldn't be appropriate. The few piston helo models I've checked out get around that by just not having much in the way of engine instruments. That looks OK on the tiny panel of, say, a Bell 47, where there are just a handful of instruments and only a couple engine instruments, but the big, wide S-56 panels are chock full of engine instruments that would look mighty strange if they all didn't work. All of that is moot as long as turbine flight models with this 3D model crash the sim. (I have no idea why that happens!)

With a piston flight model adapted from the AlphaSims S-55 the model has a very strong right turning tendency. The S-55'ds panel includes a rotor trim gauge that allows one to trim out a left turning tendency but sadly, not a right turning tendency. It also has an extreme forward (downward) pitch in forward flight. I've noticed that some other helicopter models (I haven't flown very many) also seem to exaggerate a helicopter's need to "lean" into the direction of flight, but in this case it's extremely exaggerated, with the nose pointed almost straight down at forward speeds well below the S-56's cruising speed.

I will continue to experiment but I am rapidly running out of ideas, as is David. Helicopters are far outside of our comfort zone and even further outside our areas of expertise. We are blundering along in the dark and we'd really like to hook up with someone who actually knows what they're doing.

I have no idea which 'David' you are talking about, but as far as tweaking flight models (AIR files) David Gibson in Australia did a very nice job on the one for Owen Hewitt's Jet Ranger. YES, you have to have hands on the cyclic at all times, but then.. same for the real 206!

And yes.. frustration attempting to get reciprocal engines in the cfg. to display properly, perform properly, and look right on gauges. FS9 has never been Heli-friendly! And as far as I know, all heli's in flightsim incorporates some sort of 'work around' to get them to fly somewhat correctly! SOME better than others!
good luck,
cheers,
Dave

[Mick]

I have no idea which 'David' you are talking about, but as far as tweaking flight models (AIR files) David Gibson in Australia did a very nice job on the one for Owen Hewitt's Jet Ranger. YES, you have to have hands on the cyclic at all times, but then.. same for the real 206!

And yes.. frustration attempting to get reciprocal engines in the cfg. to display properly, perform properly, and look right on gauges. FS9 has never been Heli-friendly! And as far as I know, all heli's in flightsim incorporates some sort of 'work around' to get them to fly somewhat correctly! SOME better than others!
good luck,
cheers,
Dave

The David I referred to is David Wooster, who I have been painting planes for since many years ago, and for a couple years now since the end of a hiatus in our partnership.

We've noticed how FS is heli-unfriendly! And every FS helicopter I've looked at has had some sort of workaround that even a flight model novice like me could recognize as being rather odd . At first we thought it was just that FS didn't like twin piston helos, but it soon became apparent that it just doesn't like any helicopters very much, especially those with more than one engine, piston or turbine. Small piston singles can adapt the flight model from the stock R-22, and small turboshaft singles can start with the stock Bell Jet Ranger. The further they get from those two starting pints, the more difficult it gets.

We seem to have the twin recip powerplant working fairly well, other than an apparently uncorrectable glitch that causes both of the paired engine gauges reporting on only the first engine. That's OK once you get both engines running. The big problem is getting the bird to straighten up (literally) and fly right. It takes off and lands pretty well, but once in the air it wants to turn right all the time and it drops its nose radically with any forward speed.

[Motormouse]

I have no idea where I got this Wessex from! might have been alphasim, but it's been so long, and I don't have a read me for documentation.
Dave

That's the Simshed Wessex ; available at Simviation as Simshed is now gone.

ttfn

Pete

[Bushi]

That's the Simshed Wessex ; available at Simviation as Simshed is now gone.

ttfn

Pete

ah yes! thanks for helping clear away the cobwebs! I hadn't pulled that beast out of the hangar for a few years.. till today!!

[Bushi]

The David I referred to is David Wooster, who I have been painting planes for since many years ago, and for a couple years now since the end of a hiatus in our partnership.

We've noticed how FS is heli-unfriendly! And every FS helicopter I've looked at has had some sort of workaround that even a flight model novice like me could recognize as being rather odd . At first we thought it was just that FS didn't like twin piston helos, but it soon became apparent that it just doesn't like any helicopters very much, especially those with more than one engine, piston or turbine. Small piston singles can adapt the flight model from the stock R-22, and small turboshaft singles can start with the stock Bell Jet Ranger. The further they get from those two starting pints, the more difficult it gets.

We seem to have the twin recip powerplant working fairly well, other than an apparently uncorrectable glitch that causes both of the paired engine gauges reporting on only the first engine. That's OK once you get both engines running. The big problem is getting the bird to straighten up (literally) and fly right. It takes off and lands pretty well, but once in the air it wants to turn right all the time and it drops its nose radically with any forward speed.

When I started with my current repaints of Owen Hewitts Bell 206, there were some issues with handling. Some because it was originally modeled after the default 206. I found a replacement cfg. and tweaked it a bit myself, mostly contact points, but I was making so many little changes.. I honestly don't know what bits I've changed anymore!

And I grabbed David Gibsons replacement AIR file. At one point in the process, I was mixing stuff around, and was distressed to find that my jet range now had an insanely nose down attitude in level flight at cruise speed.. then realized I wasn't using the correct air file with the cfg! THAT was all it took to screw things up.
And even now, the heli flight dynamics in FS seem to give a more prominent nose down attitude than I would like. I had put it down to the fact that Owen had modeled the mast to be perpendicular to the datum line, as in, ensuring the rotor disc was level with the horizon with the heli on the tall skids, rather than having a 4* forward tilt to the disc, (which is annoying with the low skid model as you have to 'rock' her up on to the front of the skids with some forward cyclic before attempting to hover.. or she back up!) So.. when modeling your new heli, if there was some way to angle the rotor disc forward, or make FS think that rotor was tilted forward, you might be able to get the nose down issue rectified.

Those were just some thoughts I had while mucking about with the Jet Ranger...

I've attached a few screenshots of my MD500E by Peter Nemeth. They show how he has tilted the rotor disc forward in relation to the fuselage, and the resulting attitudes parked, rotated up on the skids to get the fuselage level, and in cruise level flight. I'm hoping I'm giving you some constructive ideas on handling a few of the issues you are having.



I'm confident that given the correct parameters in the AIR and cfg files, working in concert, one CAN get a heli to fly in a suitable fashion in FS. As you say... all you need is someone that understands the heli flight model to throw in with you guys!

And yes.. you are not the first to notice that the engine instruments, even though for separate engines... act as one.



cheers
Dave

[Mick]

Thanks Dave!

That's helpful and encouraging.

I don't recall the details after weeks or months, but some of my early troubles might be due to not using paired aircraft.cfg and air files. I will remember that in further experiments.

When I get a little time I will try adapting the Merlin flight model as was suggested above, one that I didn't try previously. And if need be I'll see if David can angle the rotor disc forward on the model. That should help with the nose-down angle if it persists with an otherwise useful pair of flight files.

While I experiment, David still has a lot to do on his end, and both of us are in periods when life isn't leaving either of us a whole lot of hobby time. But we will continue the struggle. There is far too much done to consider abandoning the project at this point.

[Bushi]

Thanks Dave!

That's helpful and encouraging.

I don't recall the details after weeks or months, but some of my early troubles might be due to not using paired aircraft.cfg and air files. I will remember that in further experiments.

When I get a little time I will try adapting the Merlin flight model as was suggested above, one that I didn't try previously. And if need be I'll see if David can angle the rotor disc forward on the model. That should help with the nose-down angle if it persists with an otherwise useful pair of flight files.

While I experiment, David still has a lot to do on his end, and both of us are in periods when life isn't leaving either of us a whole lot of hobby time. But we will continue the struggle. There is far too much done to consider abandoning the project at this point.

Happy I could hopefully shed some light on the project, even with my limited understanding!

Further to the point concerning rotor disc / mast angle parameters and their association with the fuselage "deck angle", I took the big old Chinook up for a hop, to illustrate it as best I could. as they say, a picture is worth a thousand words!

When you apply power to lift off, you need to pull the collective back to arrest forward movement, and although a tricky balancing act (like the real deal) once established, she will lift off vertically into a nice stable hover...with.. as you can see, the nose quite high. (rotor disc level with horizon)

Then, once in a nice high speed cruise, the difference in angle of the disc to the fuselage 'deck' results in a VERY level attitude...just like the real thing!

This is about as visual an example of this correlation I can think of..at least in MY helo collection! :-)

Again, hoping this sheds some light on one aspect of the design of helicopters in FS.
Cheers
Dave

Chinook in hover

Chinook in cruise

[fnkybnch]

Mick--

Try contacting euroastar350 here at SOH. I have George's Bell 210 and 212 and they're great! He should be able to help you.


Mark

[Mick]

Mick--
Try contacting euroastar350 here at SOH. I have George's Bell 210 and 212 and they're great! He should be able to help you.
Mark

Thanks Mark,

I'm reluctant to track down someone who hasn't come forward to volunteer, but I will do that if necessary. Meanwhile, I still have a couple ideas of my own to try, plus a couple that were shared with me via PM. Right now both David and I have just been hit with things that leave us with very little hobby time right now.

[PhantomTweak]

If I may make few suggestions...

First and foremost read through http://www.hovercontrol.com/artman/p...ticle_67.shtml and http://www.hovercontrol.com/artman/p...ticle_88.shtml . Great information on helicopter FD's.

What I use for the HC H412...

[WEIGHT_AND_BALANCE]max_gross_weight=11900                         // (pounds)
empty_weight=6959                             // (pounds)


reference_datum_position     =  0.0000, 0.0000, 0.0000       // (feet) distance from FlightSim Reference position: (1/4 chord, centerline, waterline)
empty_weight_CG_position=0.0, 0.0, -0.2   // (feet) longitudinal, lateral, vertical distance from specified datum


max_number_of_stations=10


station_load.0="250,  6.0, 1.17, 0.0, Pilot"               //     Weight (lbs), longitudinal, lateral, vertical positions from datum (feet)
station_load.1="250,  6.0,  -1.17, 0.0, Co-Pilot"                  //     Weight (lbs), longitudinal, lateral, vertical positions from datum (feet)
station_load.2="240,  0.0,  0.00, -0.2, PassengerArea"                //     Weight (lbs), longitudinal, lateral, vertical positions from datum (feet)
station_load.3="100,  0.0,  0.00, 0.0, RearCargo"                //     Weight (lbs), longitudinal, lateral, vertical positions from datum (feet)
station_load.4="0,  0.0,  25.00, 4.0, Hoist"                //     Weight (lbs), longitudinal, lateral, vertical positions from datum (feet)
station_load.5="0,  0.0,  0.00, -2.85, ExtCargo-Hook"                //     Weight (lbs), longitudinal, lateral, vertical positions from datum (feet)


;Moments of Inertia
empty_weight_pitch_MOI=10000
empty_weight_roll_MOI=9500
empty_weight_yaw_MOI=23000
empty_weight_coupled_MOI=0


//---------------------------------------------------------------------------------------------
[Helicopter]
low_realism_stability_scale=.40, .35, .80             //Pitch , Bank, Yaw Scalars on Stability in Low Realism Settings
reference_length           =42.40
reference_frontal_area     =134.1
reference_side_area        =208.6
side_aero_center           =0.00
lift_aero_center           =-0.1
cyclic_roll_control_scalar = 1.5   //2.0
cyclic_pitch_control_scalar= 2.0      //2.9
rotor_brake_scalar         =1.0
tail_rotor_translating_scalar =1.80
correlator_available       =1
collective_on_rotor_torque_scalar =1.25
pedal_control_scalar       =1.30
torque_scalar              =1.25
right_trim_scalar          =1.15


[fuselage_aerodynamics]
drag_force_cf      = 0.095
side_drag_force_cf = 18.0
pitch_damp_cf      =-2.00
roll_damp_cf       =-1.00
yaw_damp_cf        =-0.35
yaw_stability_cf   = 0.285


[MainRotor]
Position               = 0.95, 0, 6.90                     
Radius                 = 24.2 
static_pitch_angle     = -3.25                          
max_disc_angle         = 3.14
RatedRpm               = 324
Number_of_blades       = 4
Weight_per_blade       = 106.0
Weight_to_moi_factor   = 0.75
inflow_vel_reference   = 65.0


[SecondaryRotor]
Position               =-28.90, 1.28, 8.218                    
TailRotor              = 1
Radius                 = 5.2                                 
Weight_per_blade       = 24.2
Number_of_blades       = 2


//---------------------------------------------------------------------------

and the .air file: Hovercontrol_412_PersonalEdition.zip

Look at records 1400 through 1404 in particular, although the Record 1100 entries are important too.

I hope these help a little.

Good luck. My wrist is still in a cast or I would volunteer more FDE assistance. It just hurts too much to type too much ATM. Makes such work very difficult, and flight tests impossible. With any luck, only 10 days left in this bloody thing, though.

I wish you the very best with your project...
Pat☺

[Mick]

If I may make few suggestions... I hope these help a little.

Good luck. My wrist is still in a cast or I would volunteer more FDE assistance. It just hurts too much to type too much ATM. Makes such work very difficult, and flight tests impossible. With any luck, only 10 days left in this bloody thing, though.

I wish you the very best with your project...

Pat☺

Wow, thanks Pat!

Some of this looks to be a bit over my head, but I think David will understand all of it. (I hope so!)

Right now we're both rather pressed for time, but we're getting some work done. The VC and the flight model are both in rather preliminary form and the 2D panels need more work, so we're a long way from being finished.

We might have to ask for more help when your wrist is better. I hope it will feel fine when that cast comes off! Maybe by then we'll feel compelled to ask for more help, but with luck we might get it done with the information you've provided.

I really appreciate this and I'm sure David will too.

[PhantomTweak]

It's my pleasure

I have done a number of other helicopters as well, but the one I showed, I feel, is my best so far. I didn't have very much in the way of raw data from the real-life bird, but given the superb work Hovercontrol put into it, I think I got it pretty close. I don't know if the Hovercontrol 412 Personal Edition is still available to download from anywhere, but if it is, you should look at it for hints as to the two engine stuff, electrical systems, and so on. The cockpit XML files are really remarkable.
Of course, knowing helo's, I'm probably somewhere off in left field, but heck, I did my best...

I've done quite a few other helicopters as well. If there's another version, or an entirely different bird, that might be better, I can see if I worked on a bird I have that comes closer. Once I get free of the medical torture device(s) I'm in (cracked my kneecap too), I can try to help a little, should you desire. Any data from the real bird, top speed, power curves vs altitude and so on, would make a huge difference.

BTW: I'm not too bad on making HTR cfg files for different helicopters, too, should y'all want one for yours.

Anywho, I wish you all the best. I'll get back once I'm free from the arm guard.
Have fun!
Pat☺

[Mick]

It's my pleasure

I have done a number of other helicopters as well, but the one I showed, I feel, is my best so far. I didn't have very much in the way of raw data from the real-life bird, but given the superb work Hovercontrol put into it, I think I got it pretty close. I don't know if the Hovercontrol 412 Personal Edition is still available to download from anywhere, but if it is, you should look at it for hints as to the two engine stuff, electrical systems, and so on. The cockpit XML files are really remarkable.
Of course, knowing helo's, I'm probably somewhere off in left field, but heck, I did my best...

I've done quite a few other helicopters as well. If there's another version, or an entirely different bird, that might be better, I can see if I worked on a bird I have that comes closer. Once I get free of the medical torture device(s) I'm in (cracked my kneecap too), I can try to help a little, should you desire. Any data from the real bird, top speed, power curves vs altitude and so on, would make a huge difference.

BTW: I'm not too bad on making HTR cfg files for different helicopters, too, should y'all want one for yours.

Anywho, I wish you all the best. I'll get back once I'm free from the arm guard.
Have fun!
Pat☺

Again, Wow and Thanks!

I have suddenly become pressed for time. I perused your information and it seems a bit over my head, but maybe not once I get a chance to really delve into it. I've also called it to David's attention. He at least knows the basics of flight models, which is a lot more than I know. Alas, he has also rather suddenly become rather pressed for time. Hopefully both of us will be less swamped with real llife pressures pretty soon.

We have plenty of information about the real helicopter; power, weight, speeds, that sort of thing. We just don't know how to use it to make the model fly right.

In fact, since we know that helicopters are hard, maybe we don't really want it to fly quite right as would a real S-56; we want it to fly pretty well but also reasonably easily in FS, with performance not too radically different from what the real helo had but maybe a little easier to fly. It comforts me some that the real HR2S had an automated control system that made the helicopter handle like an airplane. The Army left it off it's H-37A initially, but soon changed its mind and added a similar system to upgrade the H-37A to H-37B standards. So our model doesn't have to be as hard to fly as a real helicopter.

I have a feeling that we will still be struggling when you get healed up, especially since we have so much else to work on along with the flight files, and we're presently getting so little hobby tome to work on it all. So if you are interested in joining our project when you're able to work a keyboard in comfort, we will almost certainly still need your help.

I don't mean to pry (OK, maybe a little) but I can't help asking how you injured your knee and wrist. And I wish you quick and effective healing.

[PhantomTweak]

So if you are interested in joining our project when you're able to work a keyboard in comfort, we will almost certainly still need your help.

I'm still waiting to get healed to where I can work a kb decently. I need to try to finish up adding HARM missiles to the latest TackPac version of the FSDT F/A-18C. But I will be happy to help you all the best I can as soon as I am able.
It's vital to work the FDE that there is a relatively flyable bird, btw. Like a complete model, pretty decent panel, like that. Gotta fly it to test it Textures, sound, the little details, not really important, you know? just so long as there are usable gauges, and i'm not sitting on nothing, I'm good. It kinda messes with my pea-brain to fly around sitting on air, you know?

We have plenty of information about the real helicopter; power, weight, speeds, that sort of thing. We just don't know how to use it to make the model fly right.

In fact, since we know that helicopters are hard, maybe we don't really want it to fly quite right as would a real S-56; we want it to fly pretty well but also reasonably easily in FS, with performance not too radically different from what the real helo had but maybe a little easier to fly. It comforts me some that the real HR2S had an automated control system that made the helicopter handle like an airplane. The Army left it off it's H-37A initially, but soon changed its mind and added a similar system to upgrade the H-37A to H-37B standards. So our model doesn't have to be as hard to fly as a real helicopter.

Not all that hard to make something easier
The more info, the easier it is to get a good, pardon the pun, take-off point. Once there, that's when the hard work starts. But it can be made realistic, but still easier to fly than the real. As far as I know, however, programming an AFCS, or even a control assist type system is a real adventure, and I am pretty much a tyro at HTML. Best I can offer is to make the FDE as though the controls are assisted by making it fly like there is. Does that make sense?
There IS an excellent Autopilot just for helo's, btw. I don't know it'll work in FS9, but can test it out.

I don't mean to pry (OK, maybe a little) but I can't help asking how you injured your knee and wrist. And I wish you quick and effective healing.

Promise not to laugh!
I was on the bottom step of a low, two step, step-stool. 6" at most. Working on opening a Tupperware container. It opened, suddenly, and I fell off backward. Tried to take a step back to stay vertical, caught my heel on the floor (great traction on my shoes, darn it), and went down. Landed on my left knee, butt, and threw my right right hand out to break my fall, not my skull. My left kneecap cracked right across it's entire width. My right arm's radius bone tip, where it meets the wrist broke off. 4th break for my right arm, btw.
Naturally, the doctors mis-read the wrist x-rays, saying it was just a sprain.
No walking for me yet, either. Wheel chair just to go potty. Hard to move around using a broken wrist, too, btw.
I finally, 1.5 months later, convinced the doctors to look at my wrist again. By now, it had a nice drop down between arm and hand. NOW they could see the bone had broken off and drifted. Sheesh. In for surgery to rebreak it, as it had begun to knit already, and put in a plate and screw it down to hold it all together. A lot of screws...
So that's still healing, and will most likely pain me somewhat the rest of my life. Just like the plate and screws on the other bone, the ulna, in the same arm. Motorcycle accident shattered the whole thing. Little Old Lady pulled out in front of me. Anywho, that's a whole nother adventure, like the wild horse that took my left eye...
I can, though, detect weather for a treat, as well as active radar systems. Weird, I know. Nearby lightning hurts like heck, too.
I,m probably the only guy that knows intimately how to do a good PLF, and didn't when he should have most. Thank goodness for a wonderful...beyond wonderful!...wife to help me, and real good Medicare supplemental insurance.

This all took me about 3 hours to type out. Now you see my conundrum. No flying, though. Can't hold the joystick with the cast in the way...

Try not to laugh too hard, please. Makes liquids shoot out your nose unexpectedly...
Pat

[huub vink]

That's the Simshed Wessex ; available at Simviation as Simshed is now gone.

ttfn

Pete

And one of the best helicopters around in my opinion, including its flight model. But that's of course based on personal presence.

Cheers,
Huub

[Mick]

... It's vital to work the FDE that there is a relatively flyable bird, btw. Like a complete model, pretty decent panel, like that. Gotta fly it to test it Textures, sound, the little details, not really important, you know? just so long as there are usable gauges, and I'm not sitting on nothing, I'm good. It kinda messes with my pea-brain to fly around sitting on air, you know? Pat

The bird is flyable now, at least for test purposes. The present flight model is adapted (without great success) from the AlphaSims Sikorsky S-55/H-19/HRS with only a near-minimum of changes: contact points, second engine installed, UI sections, lights, not much else. The performance is like the S-55, which was about half as fast as the S-56.

The worst problems are a strong right turn tendency and an extreme nose-down attitude in forward flight at even fairly low speeds. David followed the earlier suggestion to angle the rotor shaft four degrees back, but that's a tiny fraction of the excessive pitch angle. Alpha provides a rotor trim gauge for the S-55 that allows trimming out a left turning tendency but it doesn't work in the direction we need.

Two 3D models are finished and the other needs some final work. The 2D panels are almost finished except for a couple items that should be added to the panel background that are giving me fits. The VC is built but not yet painted. The H-37 VC panel needs tweakage and the HR2S VC panel isn't started yet. The sounds, a mash-up of the AlphaSims S-55 rotor sounds and Nigel's twin R-2800 sounds from Milton's Ventura are finished and sound great. Almost twenty skins are painted.

So that's where we are now. With work to be done on the HR2S 3D model, the 2D panel needing final tweaks, VCs to be finished and painted, we have plenty to do before we have to dive into the flight model. You will almost certainly be all healed up by the time we have to stop procrastinating on it, especially since both David and I have been hit with true life issues that are seriously impacting out hobby time. I think it's a corolary of Murphy's Law of FS Modeling that any time you post a public request for help, something will happen that keeps you from paying as much time and attention as they deserve to the answers you get.

... it can be made realistic, but still easier to fly than the real. As far as I know, however, programming an AFCS, or even a control assist type system is a real adventure, and I am pretty much a tyro at HTML. Best I can offer is to make the FDE as though the controls are assisted by making it fly like there is. Does that make sense? Pat

Yes, it makes sense! We don't need, or even want, an actual, functional Automatic Stability Equipment (HR2S) or Lear Autostabilization System (H-37B). We're just happy to have an excuse if our helicopter isn't as hard to fly as some might think it should be.

Promise not to laugh! I was on the bottom step of a low, two step, step-stool... Pat

No laughter! My sincere sympathy for your injuries and the prolonged recovery period. I've known of other folks who got seriously mangled in home accidents. I chuckled at your mention of how long it takes you to type in your present condition because I'm typing this one click at a time with the mouse on the on-screen keyboard, necessary because a certain cat, after performing an elegant full body keyboard flop, is laying against the keyboard with his head on my mouse hand. But you're stuck with your situation for now, while I could escape mine if I were to risk moving the cat. That would involve a certain amount of ripped, torn flesh and flowing blood, but at least I have the option.

[PhantomTweak]

The worst problems are a strong right turn tendency and an extreme nose-down attitude in forward flight at even fairly low speeds. David followed the earlier suggestion to angle the rotor shaft four degrees back, but that's a tiny fraction of the excessive pitch angle. Alpha provides a rotor trim gauge for the S-55 that allows trimming out a left turning tendency but it doesn't work in the direction we need.

Actually, there are ways to fix these sorts of troubles, as well as the top speed. A mix of .air file and aircraft.cfg entries. One thing David should have done is set the static angle of the main rotor forward, not aft, and then adjust the .air file settings to match. See my examples to find the setting I mention. The left turn tendency can be adjusted with the tail rotor settings in the .air file. The ease or difficulty to fly has to do with the low realism settings, placement and weight of the station loads, and MOi values. The station weight values and placement can affect the attitude as well.
All this "stuff" is complexly interrelated and one small detail can affect something that doesn't seem at all related to it in any way. Be cautious about what you adjust, how much, and in which numeric direction.

I chuckled at your mention of how long it takes you to type in your present condition because I'm typing this one click at a time with the mouse on the on-screen keyboard, necessary because a certain cat, after performing an elegant full body keyboard flop, is laying against the keyboard with his head on my mouse hand. But you're stuck with your situation for now, while I could escape mine if I were to risk moving the cat. That would involve a certain amount of ripped, torn flesh and flowing blood, but at least I have the option.

I can relate!
We have 3. Was 4, but one of the two brothers we had passed on recently. He had a good long life. And they are all experts at the flop.
All we can do is love them, and, of course, care for their house

I'll really get helping as soon as possible
Pat










i

[Mick]

Actually, there are ways to fix these sorts of troubles, as well as the top speed. A mix of .air file and aircraft.cfg entries.

Well, that's pretty much what we figured, but neither of us knows how! We're just full of vague generalities but rather empty of specific knowledge. I've learned more than I ever knew before just from your posts. David knows a lot more than I do from his experience building models, but he's almost a novice with helicopters.

One thing David should have done is set the static angle of the main rotor forward, not aft, and then adjust the .air file settings to match...

I will let him know if he hasn't read it here already (Maybe he hasn't - life is pressing him for time even more than me these days.)

I can relate! We have 3. Was 4, but one of the two brothers we had passed on recently. He had a good long life. And they are all experts at the flop.

You have my sympathy for your loss. I'm down to my last cat now. We lost Rowdy's co-kitty a couple years ago to cancer. I'd love to adopt more but I'm in my seventies and lack suitable godparents, so I don't feel right about adopting a pet that I would almost certainly leave an orphan.[/QUOTE]

All we can do is love them, and, of course, care for their house

Yep. As for caring for their house, Rowdy is a firm believer in the old adage, "Dogs have masters; cats have staff."

I'll really get helping as soon as possible

I really appreciate that and I'm sure David does too, or will when he sees your comment. There is absolutely no rush. We have a lot to do before we can seriously delve into the flight model. The H-37 VC is just started, the VC panel isn't finished and the VC isn't painted. The HR2S VC isn't even started yet. The 2D panels still need work. We still need a few slightly different versions of both the H-37 and HR2S 3D models.And work is barely moving along on these things because both of us have come into times when real life matters have reduced out hobby time to almost nothing for at least a little while yet. So we appreciate your willingness to help and we gratefully accept, but there is absolutely no rush. If you were ready to jump in right now, we'd probably have to keep you waiting around.

[Bushi]

Okay, first, I agree with Huub that the simviation Wessex is a very nice helicopter to fly. Stable, no funky issues, even when flying with a rather well used twist grip joystick that sometimes gets squirrelly with the rotation axis!

I would download it, fly it a bit, see what you think of it's dynamics, and what you could do to adapt some of these to your project as far as flying stability is concerned.

As for the rotor mast angle. Now.. I could be so far off here in my thinking, but it seems to me that FS doesn't actually care WHAT angle the fuselage is modeled at when it comes to flight characteristics. It seems to be HEAVILY if not solely reliant on what that rotor disc angle is. In the hover.. it wants that disc LEVEL, and in forward flight, it want's it canted forward.. the more it is canted.. the faster you are going. Just like the real aircraft. Hence why you see all these canted forward rotors in real life.. and why they all are tail down in the hover as a result.

My Jet Ranger unfortunately has a mast that is vertical to the fuselage, meaning that in the hover, the fuse is level, as is the rotor disc. so.. in forward flight, with the rotor canted forward.. so is the fuselage. The air file and dfg I'm now using has taken a bit of that nose down attitude out of it, to the point I can live with it... but I'm still convinced that the difference in angle between the rotor disc and the fuselage centerline in the model is a big factor in the heli's attitude in flight. Based on my Nemeth MD 500E wih a distinctly forward cant to the disc, and the Alphasim Chinook as well.

I've attached a couple of screenshots of my Jet Ranger on floats (so I could use the upper float structure to better illustrate the centerline of the heli) .. one showing an unedited forward cruise flight Jet Ranger, and the other in which I put the bird into a hover, (level fuselage) and added the forward tilted main rotor to the image.
The related angles to rotor disc (red), fuselage (green), and horizon (yellow), angles with and without that disc (mast to fuselage) being angled is quite apparent.

I think that playing with the rotor disc to fuselage angle will still yield a more 'livable' nose down attitude for your heli.

It's too bad there isn't a way to actually adjust this while in flight!!!!!

But hey.. I'm no modeler by far!!! I'm just basing my thoughts here on observations from flying several heli's in the sim.

And hoping that with enough input from members here, you guys can put something together that you will be VERY proud of!

Cheers
Dave

[Mick]

Thanks for your comments.

We've set the flight model aside for a bit. David is busy dealing with a serious illness in his family and I've been battered with demands on my time and attention, not to mention that flight modeling is far from my areas of expertise.

For the tie being we're back to a flight model that David apparently derived from the stock Robinson. With it the S-56 flies like an R-22, which is not bad but probably not much like an S-56. The turning tendency I grumbled about with the modified S-55 flight model is gone, and adjusting the rotor seems to have helped quite a bit (but still not enough) with the excessive forward pitch attitude in forward flight. Aside from that, the most obvious thing is that it has the top speed of an R-22, which is about half the speed of the S-56, which was a helicopter world speed record holder.

Anyway, for now, as time allows (not much these days) we will work on finishing up the VCs and the variants of the visual models. We have a LOT of work to do in those areas and not much hobby time to do it, so it will keep us plenty busy until Pat is healed up and able to help with the flight model.

We have learned a lot from the comments you and others have made here and we really appreciate them, but we are still novices with helicopters and especially with their flight models.