Fairchild C-119

[PeteHam]

In the past there's been some discussion regarding the Fairchild C119 by Daisuke Yamamoto.

Todate I still haven't found a good flight cfg for this classic.

One version has it tied to the Beech Baron air file, and in several other downloads I've tried have a modified cfg , but it still flies like a dog.

I'm sure there's enough interest and tallented guys here to do justice to this fine aircraft.

Please ........

Thanks guys,

Pete.

[A26]

I second that!

a26

[Milton Shupe]

In the past there's been some discussion regarding the Fairchild C119 by Daisuke Yamamoto.

Todate I still haven't found a good flight cfg for this classic.

One version has it tied to the Beech Baron air file, and in several other downloads I've tried have a modified cfg , but it still flies like a dog.

I'm sure there's enough interest and tallented guys here to do justice to this fine aircraft.

Please ........

Thanks guys,

Pete.

I flew this years ago in FS9, maybe FS8. If you wish to encourage someone to do the flight model, why not do the research for the performance data, and maybe come up with some load out configs. I.E. do you want it loaded, half loaded, or empty? Maybe even come up with a POH or other helpful data.

That might encourage someone to jump on it.

EDIT: Here is a nice info link about history: http://www.ruudleeuw.com/c119-info.htm

[Willy]

I've known of a few people who have tweaked it, but I'm not sure how far along they got with it. Milton makes an excellant suggestion.

[OBIO]

Once upon a time, before my last major HD crash...or maybe the HD crash before that...I had the C-82 and C-119 installed. I had a FDE set sent to me that was really nice....now I have no idea how close it was to the real thing as I have never seen a real C-119, let alone fly one...but the plane handled great in all areas of flight. Was a real joy to fly. I even tweaked that FDE a bit to include the jet pack thingie up on top and did up a sound pack to go along with it. I have the sound pack, and the paint template...but not the FDE. Let me shoot a PM to the guy who sent me the FDE for the C-119 and see if he would be kind enough to shoot me another copy of it.

OBIO

[Brian_Gladden]

The Baron tweaked flight dynamics were done by me and Lizardo.

The main problem is that it was one of the authors first projects and when he built the model. the "zero" reference point was not near the center of the 3D model (optimal is the approximate COG of the real deal) and instead, was located in the rear of the flight deck.

This makes it nearly impossible to get a good flying flight model. It always needs wayyyyy to much pitch trim and weight an balance is nearly impossible to get right. When the model was generated, it also screwed up the values in the air file, hence the use of the Baron's (FS 2002) air file. Perhaps the FS 2004 DC-3 would be more appropriate now...

It's really too bad since I love the VC in the bird. The only other choice is Mike Stone's C-119. Which hasn't got a VC.

If anyone has Daisuke's e-mail address, perhaps he could be persuaded to either redoing the model with the COG relocated or releasing the source files for re-work.

[Milton Shupe]

... snipped ...

... perhaps he could be persuaded to either redoing the model with the COG relocated or releasing the source files for re-work.

Brian, just to be clear, the model's location in the design program sets only the FS Reference Point. The CoG can be moved to anywhere from there using the aircraft.cfg statement:

reference_datum_position = 0, 0, 0 //this is the center of mass set from the design program
empty_weight_CG_position = 0, 0, 0 // You can move the CoG with this statement giving offset from the reference datum (fore/aft-left/right-up/down)

[PeteHam]

I've got a copy of the Fairchild C119B & C Flight Manual for a start.

Pete.

[Brian_Gladden]

Brian, just to be clear, the model's location in the design program sets only the FS Reference Point. The CoG can be moved to anywhere from there using the aircraft.cfg statement:

reference_datum_position = 0, 0, 0 //this is the center of mass set from the design program
empty_weight_CG_position = 0, 0, 0 // You can move the CoG with this statement giving offset from the reference datum (fore/aft-left/right-up/down)

Correct. However , even with tweaking the COG in the cfg, if the model's reference point is in a weird place, it becomes very difficult to get the plane to fly right.

[Milton Shupe]

I downloaded the aircraft and his fix from Flightsim. Took her for a spin. The CoG was at 10% MAC and a lot of trim was required to get her up, and a lot of negative trim required to fly level.

So, I corrected the CoG and adjusted the air file for proper trim at level flight. She now lifts off with less than 2 degrees positive trim and one notch of flaps easily without getting vertical, also lifts off by herself with 2 degrees positive trim and no flaps at about 118kias.

Landing is gentle and graceful with just a few degrees of up trim. She's a pussycat.

Now with all that, the performance numbers are not accurate, stall speeds are likely too slow, and cruise and top speeds are slow. But she flys through all phases nicely. It is a starting point.

[PeteHam]

That's great news Milton

I'm pleased there's those like you who are knowlegable in these mods.

I've tried fiddling the numbers ( might add here that I haven't got a clue as to what I'm doing ) and the whole thing turns into a can of worms.

From flipping over and over on starting the sim to massive amounts of trim to try and maintain control , to going ballistic when I lower flaps ...........

Eventually the aircraft crashes .... wonder why I can't find anymore test pilots

Pete.

[OBIO]

Pete

It sounds like you and I flunked out of the same Aeronautics class LOL! I can't do diddly squat with flight dynamics unless a mountain size lump of luck happens to fall into the mix.

Tim

[PeteHam]

Pete

It sounds like you and I flunked out of the same Aeronautics class LOL!

Tim

Yeah , maybe we should have paid more attention to the tutor instead of daydreaming

Pete.

[aeromed202]

Just glancing at it I started messing with the FDs at some point on this one. I have a day off coming up so I'll see if my humble hacks show any promise. The points Milton identified are usually not too hard to resolve.

Pete, if you could digest that manual a bit and post some data I could use them as a start. Airspeeds and settings for takeoff, cruise, landings and so forth. Even a handful would help. Thanks.




Just noticed that Robert Coady did updated dynamics for the aircraft c119bxcr.zip at Flightsim. I presume this the same base model but I have not tried out his mods. Would be worth a look.

[Milton Shupe]

Here are the tweaks I did just to get her more flyable. She is not accurate but at least easily flyable.

For a more accurate FM, I would start from scratch because the air file tables need to match up better with this aircraft but this is useable.

Thanks for taking on the task aeromed202.

[Z-claudius24]

Hi,

Thank you..

[PeteHam]

Just glancing at it I started messing with the FDs at some point on this one. I have a day off coming up so I'll see if my humble hacks show any promise. The points Milton identified are usually not too hard to resolve.

Pete, if you could digest that manual a bit and post some data I could use them as a start. Airspeeds and settings for takeoff, cruise, landings and so forth. Even a handful would help. Thanks.

Aeromed202 , I've sent you a pm.

Thanks,

Pete.

[PeteHam]

Here are the tweaks I did just to get her more flyable. She is not accurate but at least easily flyable.

For a more accurate FM, I would start from scratch because the air file tables need to match up better with this aircraft but this is useable.

Thanks for taking on the task aeromed202.

Thanks Milton

I'll give these a try out.

Pete.

[PeteHam]

Here's some figures from the Flight Manual .............

Take Off;

50,000 lbs = 82 kts
60,000 lbs = 89 kts
64,000 lbs = 92 kts
74,000 lbs = 99 kts

Approach;

40-50,000 lbs = 82-90 kts
50-60,000 lbs = 90-100 kts
60-70,000 lbs = 100-110 kts

Max Flap speed = 140 kts

Stall Speed;
Dirty ( gear & flap down ) varies from 68 kts @ 40,000 lbs to 92 kts @ 74,000 lbs.

Hope this helps.

Pete.

[aeromed202]

Thanks all for the encouragement. I'll block out time tomorrow for this if I don't get a start tonight.

[PeteHam]

Aeromed202 , you should have a package in your mailbox
Good luck and we all look forward to the end result

No pressure
:ernae:

Pete.

[aeromed202]

Got it, thanks. As I was reading it over I was wondering about the weight and balance section of the CFG

[WEIGHT_AND_BALANCE]
max_gross_weight = 26200 // (pounds)
empty_weight = 16145 // (pounds)

The lit refers to a max of about 60000 lbs. Do the numbers in this balance section really show FS simulated weight? Did the author mean that his 26200=60000 in FS? Is FS architecture set up to understand pounds, square feet of wing area and the like realistically or is it up to the aircraft modeller? Before I get into it I need to have the right starting points. I can just use what is there but if I'd rather use real-world numbers if possible.

[PeteHam]

In Section 2 ( in the red box ) it lists the normal t/o wgt as 64,000 lbs and landing gross wgt as 60,000 lbs.

But then the charts at the rear of the manual have the t/o wgts as 54, 64 & 74,000 lbs.

Max ldg wgt is 60,000 lbs.

Hope this helps,

Pete.

[aeromed202]

Not quite. I have always wondered if those values entered as max_gross_weight and empty_weight in the CFG are true pounds in the creation of the model. If they are then I should change them to reflect reality. If they are not and do not try to relate to real weight, like a value for roll stability has no meaning other than a scalar effect value, then I can just alter them as needed to produce a result. Does that make sense?


So far I've loaded Miltons update then started making adjustments to make performance follow the manuals information. I am at the point where I try to simulate 60000 to 70000lbs of weight and need to know if those CFG weights are trying to be real or not. I think I can pretty much have it fly well no matter which way I go but for those who want to play with payloads I would prefer do it the right way.

[Milton Shupe]

Use all real world numbers. The SDK says this:

max_gross_weight = nnnnnn pounds: Maximum design gross weight of the aircraft. This parameter is used solely in FSEDIT to help determine the aerodynamic coefficients.

empty_weight = nnnnnn pounds: Total weight (in pounds) of the aircraft minus usable fuel, passengers, cargo, and expendable armament (Combat Flight Simulator aircraft). If not specified, the value previously set in the .air file will be used.

Also, recompute the MOIs