• There seems to be an uptick in Political comments in recent months. Those of us who are long time members of the site know that Political and Religious content has been banned for years. Nothing has changed. Please leave all political and religious comments out of the forums.

    If you recently joined the forums you were not presented with this restriction in the terms of service. This was due to a conversion error when we went from vBulletin to Xenforo. We have updated our terms of service to reflect these corrections.

    Please note any post refering to a politician will be considered political even if it is intended to be humor. Our experience is these topics have a way of dividing the forums and causing deep resentment among members. It is a poison to the community. We appreciate compliance with the rules.

    The Staff of SOH

  • Server side Maintenance is done. We still have an update to the forum software to run but that one will have to wait for a better time.

OH_B-24J_Liberator by The B24 Guy and Allen!

Rami

Administrator
Staff member
For The B24 Guy...I hate to be the bearer of bad tidings!

The B24 Guy,

I hate to be the bearer of bad tidings, but I am having real problems using your Overhauled Liberator in formations for the 20th Fighter Group. The lead bomber had a bad habit of oscillating several hundred feet at bombing altitude, and this then gets the other bombers to follow. I've separated the bombers by 1,000 feet altitude, but this doesn't cure the problem. AI escort flights and bomber formations are ramming into these bombers at an unsustainable rate.

This was also a problem with the FDG B-17 a while back, but I believe that Captain Kurt and Pen32Win traced these problems to FS9 elements which were left in the .air file. Now she files steady as a rock.

Here are those modified B-17 files if you need something to compare it to: http://www.sim-outhouse.com/sohforums/local_links.php?action=jump&catid=47&id=2391

How can this problem be corrected?

Thanks in advance,
 
Reply...

Hey,

Oglivie suggested trying to adjust the 1101 Primary Aerodynamics section for pitch oscillation, suggesting it was set to "0." The number listed was 3,583, near the "target" Oglivie suggested of 3,800.

Interestingly, when Pen32Win did the fix for the B-17s, that number is now listed as "0." :dizzy::kilroy:
 
Oh well...Sorry for the confusion, that's my middle name most of time though, 'Confusion' .

I did change that value though in some of my air files to correct oscilation, but also just found other changes were made including Pitch Stability, Pitch Trim, and more in the pitch section.


 
Last edited:
Here's some data I have, it's for a B-24 though but same principle for all sim aircraft:

If my memory serves me the data in the lower window corrected the oscilation. However not sure now if the
Pitch Momement due to AoA rate changed had much to do with the oscilation.
 
The Pitch Stability of -52301 does not look right in your B-17 airs. Heck, the A6M2 Zero is at -39000 and the P-38 around -60000.
 
Reply...

Oglivie,

Pen32Win corrected the airfiles in the FDG B-17 mod package...they fly nice and stable. :saturn:
 
Would using the stable stock B-24's air file provide a solution? It's practically the foundation of the overhauled model, so dimensions are identical. The Malinowski/McDaniel B-24 and PB4Y models are pretty stable also.
 
Hi All,

I thought the airfile was fairley stable. I will have to check it out.
Are the bombers under attack?

Oglivie's idea is the place to look.
Or you could use the B-17 airfile that pen32win moded and see if that fixes them.

Regards,
B24Guy
 
Reply...

Hi All,

I thought the airfile was fairley stable. I will have to check it out.
Are the bombers under attack?

Oglivie's idea is the place to look.
Or you could use the B-17 airfile that pen32win moded and see if that fixes them.

Regards,
B24Guy

The B24 Guy,

No, they do it in general flight. I use diamond and box formations.
 
Rami,

Do not use the stock B-24 airfile. The stocker has the same problem.

I fixed the problem in the OH version, but I don't recall how I did it. It's likely that I substituted the KM B-24 airfile, but I'm not sure.

I do notice that I have the empty weight cg at 0,0,0 (same as KM) in the aircraft.cfg file. It's something like -6.5,0,0 in the stocker.
 
Stock B-24D has empty_weight_CG_position = 6.5, 0, 0 // (feet) longitudinal, lateral, vertical distance from specified datum
 
a word of caution when trying to correct stability issues.

If you do to much you could stop the AI from engaging targets. unless this isn't important.
 
Give this one a try.

I put the aircraft.cfg back to stock but for the empty_weight_CG_position has been set to all "0"s since with the stock settings the aircraft wants to dive down badly with a player flying. I added needed things like [exits] [flaps.0] [LIGHTS] and set the [Views] to the right spot.

In the .air under 1011 Primary Aerodynamic I changed the *Cm_adot Pitch Moment - AoA Rate from 0 to 20000, *Cm_de Pitch Moment - Elevator (Control) from -2800 to -1800 and *Cm_q Pitch Moment - Pitch Rate (Damping) from -33000 to -63000


In my quick test set up I set the B-24s to box formation. One formation of 8 B-24s at 24,000 feet and the other formation of 8 B-24s at 24,500 feet. I followed for 20 miles and saw no movement.

View attachment 1644
 
Reply...

Allen,

Thank you! I'll try to test this later tonight, but I am going to have a tough time getting to a computer today.
 
Reply...

Allen,

I'm still having the same problem. I adjusted the weight slightly to 36,500 lbs (the dry weight of the B-24 "J" model) and it's still affecting the lead aircraft. Once that aircraft starts moving, they all eventually follow in kind.
 
Hi Rami,

Finally got a chance to test the B24.

I set up a mission to attack an airfield with 48 planes.

They flew in nice and level droped there bombs made a turn.

I checked the airfile and its the same one included in the upload.

Try changing the CFG file and increase elevator_effectiveness to 1.5 or 2 and the pitch_stability to 1.5 or 2.

Regards,

B24Guy
 
Reply...

Hi Rami,

Finally got a chance to test the B24.

I set up a mission to attack an airfield with 48 planes.

They flew in nice and level droped there bombs made a turn.

I checked the airfile and its the same one included in the upload.

Try changing the CFG file and increase elevator_effectiveness to 1.5 or 2 and the pitch_stability to 1.5 or 2.

Regards,

B24Guy

The B24 Guy,

Here is a video of the B-24 in formation.


I have also attached the files I'm using. Maybe I screwed something up.

Please excuse the audio...I was listening to Bill Maher's "New Rules," and didn't realize the audio got picked up. Oops!
 
Can you attach a mission to test with (and neeed weapons)? Also maybe it has to do with the bomb load?
 
Reply...

Allen,

Here is the mission I'm testing it with...and I'm just using the standard AI bombs, which The B24 Guy used in his .dp file...payloads one and two.

http://dev.simviation.com/download-file?file=b24d_bombs.zip&fileId=32750

You don't want to use other bomb loads because the AI only drops one. That's why the AI bombs were invented in the first place...so you get the full effect of a full load drop, getting around the limitations of the sim.
 
Back
Top