New FSXBA Hornet

[hd764jvgd843]

Hi Jimi,

the trim works as you described, and the flaps automatically lower with increasing AoA as described.

Had to take my hands off the stick in order to take the screenshot!

[jp]

Heya Peter,
It'll be VRS Superbug level in detail and functionality.
Here's my Flickr photostream with some older pics of the Hornet that I'm working on:
https://www.flickr.com/photos/27277424@N04/


Jamal

Hello Jamal,

I would like to ask if these models that you're working on will be released as freeware or payware?

[jimi08]

I can tell you that they will be released as payware under the VRS title.

[hd764jvgd843]

Hi everyone,

as I was trying to create a gauge for changing wing_dihedral under different g loads, I stumbled upon some very interesting insights: wing_dihedral (aircraft.cfg) value has no effect on airplane's performance, "as these properties are included in the stability and control derivatives which are located in the .air file."
https://social.msdn.microsoft.com/Forums/en-US/afea7f8d-7dba-494e-ae81-79b1e5c19648/flight-model-effect-of-variables-in-the-aircraft-configuration-file?forum=ESP

As far as I understand, this means in our case, that if the actual wireframe model is slightly off (anhedral wise) so will be the stability and control derivatives and as a result our flight dynamics. Meaning, without changing the model file no chance of improvement in this sector - so we have to make due with what we got, which is not so bad after all.

Last night I had a detailed look at the model and imported it through various channels into various tools. As Jimi has already stated, you only get the bare wireframe model without any reference points or control surfaces and animations, so changing even simple angels here and there in order to make small adjustments is out of the question.

In my effort to dig deeper into the .air file and flight dynamics, I found some very interesting links and tools which might me of interest, or you may already know:

- FS Thrust vs Altitude calculation method:
http://www.fsdeveloper.com/forum/threads/fs-thrust-vs-altitude-calculation-method.327725/#post-519944

- Aircraft dynamics pages, documents and utilities:
http://www.aero.sors.fr/fsairfile.html

- Designer and pilot utilities:
http://www.aero.sors.fr/designer_pilot_utilities.html

Peter

[Jamal]

As far as I understand, this means in our case, that if the actual wireframe model is slightly off (anhedral wise) so will be the stability and control derivatives and as a result our flight dynamics. Meaning, without changing the model file no chance of improvement in this sector - so we have to make due with what we got, which is not so bad after all.

3D models have zero impact on flight dynamics in FSX. You could take a square and it'll perform the exact same way. Try substituting another aircraft, like a Cessna, in the model folder.

Jamal

[strikeeagle345]

As far as I understand, this means in our case, that if the actual wireframe model is slightly off (anhedral wise) so will be the stability and control derivatives and as a result our flight dynamics. Meaning, without changing the model file no chance of improvement in this sector - so we have to make due with what we got, which is not so bad after all.

3D models have zero impact on flight dynamics in FSX. You could take a square and it'll perform the exact same way. Try substituting another aircraft, like a Cessna, in the model folder.

Jamal

That would be entertaining

[jimi08]

All of the aircraft's flight characteristics are controlled by the aircraft.cfg and .air file.  In terms of fly characteristics (lifties, draggies, stability, control authority, etc), the .air file defines EVERYTHING.  There are a few scalars in the aircraft config file that allow for quick adjustments, but they still talk back to the .air file for their initial values.

I personally use a program called "aired" to make my adjustments.  I must warn you though, using this program becomes addictive.  Expect complaints from family and loved ones...

Most non-flight essential characteristics (i.e. lights, smoke, engines, etc) can be adjusted in the aircraft.cfg file.

[hd764jvgd843]

All of the aircraft's flight characteristics are controlled by the aircraft.cfg and .air file.  In terms of fly characteristics (lifties, draggies, stability, control authority, etc), the .air file defines EVERYTHING.  There are a few scalars in the aircraft config file that allow for quick adjustments, but they still talk back to the .air file for their initial values.

I personally use a program called "aired" to make my adjustments.  I must warn you though, using this program becomes addictive.  Expect complaints from family and loved ones...

Most non-flight essential characteristics (i.e. lights, smoke, engines, etc) can be adjusted in the aircraft.cfg file.

As always, you are completely right, Jamal and Jimi!

I gave it several tries with different models. The most funny ones were flying in helicopter models with a Hornet under the hood - at least from a tower perspective.

Peter

[sonofabeech]

Hi Jimi

Firstly thanks for all the work you have put in to this project I have avidly downloaded and flown just about all the versions and have loved flying all of them.... However  ..I have a question with regards to the latest version of the jet. Is it just me or is anyone else experiencing this issue. In the pattern turning down wind at 600 feet with the jet rolled to 30 degrees AOB at about 150knots the rate of turn is different (a lot less than the previous versions) In fact it requires a little bit of back pressure on the stick at about 45 degrees to arrive at the correct distance abeam. Rolling to 30 degrees with enough stick back pressure to maintain altitude puts me at about 2.4m abeam. It has only been version xxx.15 that has done this all the previous versions have behaved as expected. Starting to think its just me as nobody else has commented on this problem. Is this a known issue?

Sonofabeech

[jimi08]

Sonofabeech,

Although no one else has chimed in on it, it makes sense now that I think about it.  Although I did not change any of the coding for the rudder logic in the Powered Approach configuration, I did have to lower the overall effectiveness of the rudder trim in order for the rudder trim to work correctly in Up & Away mode.  This translates to rudder effectiveness being to low during pattern ops.  Once I get home, I'll dig in and try to fix.  Good catch!

-Jimi

[sonofabeech]

Hi Jimi

Great to know its not just my imagination ..was about to swear off drinking beer while virtual flying 
Thanks for taking the time to fix it you're a legend..looking forward to the next update ..

Sonofa

[hd764jvgd843]

Hi everybody,

currently I am messing around with the datum reference point, station_load points, etc. In order to check them for consistency and trying to better understand their impact on flight dynamics, I have created an excel spreadsheet for easier visual comparison, and if necessary values can be linked via formulas, later. Some of them seem off, one way or the other.

Maybe someone has had this idea or done some calculations before. Awaiting your comments.

Peter

(see excel sheet below)

[Jamal]

All the reference datum does is set a zero position relative to the model mesh. For example, reference datum is set to x=0, y=0, z=0, and in the 3D workspace, the center of the model project is placed at this coordinate. Using made up numbers, this means the distance of the nose from center point will be a positive number forward (y=16ft), and the distance of the nozzles will be negative aft (y=-16ft).

Let's say then you change the reference datum to y=16. Your new coordinates for the nose will be y=0 and the nozzles y=-32ft. Of course with this, you'll have to adjust every other coordinate including contact points, stab and wings, eyepoint, etc etc.

Jamal

[jimi08]

Hey Gents,

I'm currently underway, so I will not be able to post updates until I get back home (sometime later this week).

Hi Jimi

Great to know its not just my imagination ..was about to swear off drinking beer while virtual flying  
Thanks for taking the time to fix it you're a legend..looking forward to the next update ..

Sonofa

-Sonofa, No problem and thanks.  Appreciate the kind words.

Hi everybody,

currently I am messing around with the datum reference point, station_load points, etc. In order to check them for consistency and trying to better understand their impact on flight dynamics, I have created an excel spreadsheet for easier visual comparison, and if necessary values can be linked via formulas, later. Some of them seem off, one way or the other.

Maybe someone has had this idea or done some calculations before. Awaiting your comments.

Peter

(see excel sheet below)

-Hey Peter, be careful with those numbers.... The datum reference point has become crucial in adjusting the aircraft's pitch stability , which is used to assist the FCS Auto Pitch Trim to quickly trim out the aircraft once controls are released.  Other things you will notice, are where the powerplants, payloads, and fuel tanks are situated on the aircraft.  They all are pretty much placed on the same longitudinal reference point also in an effort to keep pitch stability high to allow the pitch auto trim gauge to quickly trim the aircraft.

[hd764jvgd843]

Thanks for your feedback, I will take all of that into consideration.

Here is what I have done so far, what I intend to do, and some questions that came to my mind:
- You can now compare the following FA-18 versions: FSX, CS and New Hornet.
- I intend to make an outline/silhouette for the three side views in the spreadsheet for better visual localization of the contact points.
- So far, it seems that the values for the New Hornet seem closer to RL than the FSX or CS version ones.
- wing_pos_apex_lon and wing_pos_apex_vert seem to be merely cosmetic values. I adjusted them so the plane is positioned correctly to match wingtip vortices effects - which seemed slightly off before.
- Why are there more values present for the New Hornet under the sections wingtips, bottom and top?
- Do the sections engines, gear, wingtips, bottom and top have an impact on flight dynamics or FCS?

Some general thoughts concerning how Jimi's FCS works and how contact points could be adjusted accordingly - as I do not really understand how it works. Some explanations needed...
- Scenario A) FCS works static, like a multiplicator and/or offset to certain flight dynamic parameters. Values inside FCS gauge and 'flight_tuning' (aircraft.cfg) are tweaked to be compliant with NATOPS as best as possible.
- Scenario B) FCS works dynamically, like a program/feedback loop (like a real FCS does), ensuring that a certain end result/behavior, within NATOPS, is met.

Implications on contact points: If a dynamic mass, like a fuel tank is added - that is getting lighter gradually, in RL the FCS would compensate by decreasing elevator/aileron movement, because there is less mass to be moved over time - all other things being equal. If we move such a changing contact point further away from the cg the more has the FCS to compensate for.
- If our FCS is 'static' the best approach would be to place all changing contact points, like tanks, directly to the cg, so their impact through a change of mass is limited on the FCS.
- If our FCS is 'dynamic' the best approach would be to place all changing contact points, like tanks, to their RL positions and adjust FCS behavior accordingly, if necessary, to be NATOPS compliant.


Peter

(most current spreadsheet attached below)