Hi.I'm new to this so please be gentle.I've built somebody a trike flight sim using fsx. This has gone pretty well. I've got a control bar hanging off an upside down joystick and it has 3 42" monitors running on an ati eyefinity card. The amd 1100t keeps things running smoothly. It really is quite cool.The problem that we are now having is how the air creation trike actually flies. It reacts really well to all the control inputs until you drop the power and put it into a glide. It effectively drops like a stone with a desent rate of over 1000ft per minute. This is not how the trike that I'm modelling behaves. It's a mainair flash 2 alpha which has a glide of about 700ft per minute. I've tried altering the weights and balance with the payload and fuel but it still shows the plane nose heavy whatever I do. What I'm hoping is that somebody out there knows how to tweak some of the files to change the characteristics of the plane. Namely extend the glide.Any help would be much appreciated.Dave

How did you create the air file, Dave?.. and "Welcome" to the Avsim forums!

Hi,thanks, nice to be here.I'm using the trike that comes with fsx with no modifications. It's the air creation ultralight trike. I realise that the .air file is associated with the planes' geometry and physics but have no idea of how to edit this file.Is this where I need to start to extend the glide? I would buy a flexwing addon plane if there was such a thing.

You need both the .air file and the aircraft.cfg in the new Trike's folder, plus you will need to rename the Aircreation.air to something else, say -'MainairFlash2a.air', and then in the aircraft.cfg it needs to be:[fltsim.0]title= MainairFlash2a Blue <---- This must be a unique name.sim=MainairFlash2a <----- this is the pointer to the .air file.model= <--- ignorepanel= <--- ignoresound= <--- ignoretexture=1 <-----Needs to match the name of the texture folder it refers to.kb_checklists=Aircreation582SL_check....... <--- Just copy these from the AirCreation folder without changing kb_reference=Aircreation582SL_ref..........<---- them (if you don't need them just delete these two linesui_manufacturer="Mainair"ui_type= "Trike Ultralight"ui_variation="Yellow"atc_parking_types=RAMP <--- the rest of these lines can remain the same.That's about it, DaveWhen you've got that sorted out - post back here, or send me a pm, and we can talk about keeping the nose up. I'm online much of the day.If anyone else spots something I've missed - feel free to jump in and correct or add.

Ok. I've copied it over.

I've sent a pm, Dave. Respond to that.

I've sent a pm, Dave. Respond to that.

 

Well that's no fun. How are the rest of us suppose to learn if we wish to do this? Isn't that what forums are for?

I need to ask him a bunch of questions, try a few things out, get some answers. I've flown this 'thing' once a long time ago, VB, and I need to play with it, as well as fixing the problem once, first time. I can't do that with ten other folks muddying what he needs to do. My preferred method for fixing a pc issue, FSX, OS or whatever - is to use TeamViewer7, as it puts you right on the pc.

Sorry, VB - I didn't mean to sound brusque in any way - and I was, so my appologies.

Modifying an airfile is not a quick and easy job - I have a very, very basic idea of what needs to be fixed in parts of the airfile from working with Bernt Stolle and Alex Metzger, but that's the most that I've been involved with, and they've taken weeks to sort out. It seems that what Dave needs is someone who know airfiles, and it's just not something that can be done through a forum - particularly when it's a dummy like me.

I didn't hear back from Dave and I've spent enough time on it to know I can't fix it, and now have given up on it. Changing the CoG helped, but I can't make it not shake/stall at around 24mph. It doesn't drop like a brick anymore, but altering a dozen of the drag-AoA-pitch-elevator-angles parameters didn't do much of anything for it. It doesn't appear to respond like a normal aircraft, and I think I would probably spend another fruitless five hours looking for the right combination. I made a mistake in thinking that it might be easier than an aircraft and it's not.

I guess a 'sorry' is due to Dave as well.

Scroll down on this link and you will learn what tweak does what in the config file:

 

http://msdn.microsof...y/cc526949.aspx

 

Just save a duplicate of the config file on your desktop as a back up, and then you will be able to revert things if it all goes awry. Resetting the flight in FSX will let you test cfg changes quickly if you keep the config file open in notepad and then make a change and save it, since FS reloads the cfg file upon reset, so, no need to restart FS when testing a tweak to the flight model. Have fun!

 

Al

No worries. Interesting and shame that it can't be adjusted like the OP wants. Maybe FSX just doesn't handle low speed air dynamics well. <shrug>

Don't know, VB. There's just too many places to adjust in FSX!

Thanks for all your responses. Especially Paul who has spent some time on this.

 

I'll have a big play with the cfg and report back if I have any success. It's a shame that there isn't a decent trike model on the market as I would certainly buy it.

You might gain some clues from some of the decent ultralights that are kicking about, for example the Drifter Ultralight, and the default glider's flight model may also offer some pointers if you compare parameters, since it is possesses what is not a bad go at a flight model for one.

 

Al

It's been painful but I think I've done it.

 

As you say the air creation trike isn't too bad. What I didn't realise is just how nose heavy it is. To fix the plummeting glide I added another fuel tank in the aircraft's config file like thus :-

 

 

[fuel]

Center1= -2.70, 0.00, -10.80, 10.00, 0.00

fuel_type=1.000000

number_of_tank_selectors=1

electric_pump=0

engine_driven_pump=0

Center2= -2.70, 0.00, -10.80, 10.00, 0.00

fuel_type=1.000000

number_of_tank_selectors=1

electric_pump=0

engine_driven_pump=0

 

Then in the payload I subtracted the extra fuel from the pilot weight (-60 lbs) and voila the trike handles a lot more realistically. glide in hands off trim 450ft per min. Much better.

 

Thanks again to everybody who made suggestions.

 

Dave.