FS9 aircraft in need of design help

[KCD]

Hi all...

For several years now, I have flown and enjoyed Dan Cowan’s fine little Culver Cadet (FS9), but for all those years, it has not been correct. I'm hoping someone can assist me with a correction. The Cadet is a wonderful vintage bird and a joy to fly but for one thing.

The Cadet was originally delivered with throttle and mixture controls (no carb heat on the factory panel, although carb heat does seem to make sense). Cowan’s aircraft.cfg claims indicates an 85 HP engine at 2600 RPM. The closet engine I can find that actually was used in a Cadet was the Franklin 4AC-199-D, 85 hp (63 kW) at 2500 rpm, which makes the 2600 RPM called for in the cfg file incorrect. Be that as it may, the cfg file also indicates a constant speed propeller, but the Cadet was never delivered with a constant speed propeller; it was delivered with a Fixed Pitch propeller, probably of wooden construction. Propeller_type=0, "constant speed" is incorrect for the type.

I have tried everything I can think of to correct the errors and make the little beast fly as it was meant to, but have yet to solve the problem. The cadet flies at take-off power (above red line) until the throttle control is unrealistically reduced to almost 30%, then the engine begins to respond. The sound of the engine will reduce, but the RPMs remain constant. When the RPMs finally begin to respond to the power reduction, the engine is near idle.

I enjoy flying the Cadet and from previous attempts to correct the errors I know others do as well. It would be nice to have her representative of the original in all regards if possible. Does anyone who frequents this forum have any suggestions as to what I need to do in either the Aircraft.cfg file or with AirEd and the "Cadet.air" file???

The obvious answer would be to contact Dan Cowan, afterall he made the model. I've tried that with every e-mail address I have ever found for him, all with no luck. So, if this little bird gets fixed it will be because some interested folk like me grabbed picked up the challenge. I've tried everything I can think of, but I'm not an aircraft design person; I don't have the talent. Hopefully one of you will be able to help me out.

By the way, the Alpha C170 (I believe) has the same problem, can’t fix that one either.

Thanks in advance,

KCD

[StringBean]

Boy, this seems like deja vu all over again.

I can't find this bird in my hangar, so I downloaded it again and tweaked it as follows...

In the Cadet.air file I changed field 330 to =1

In the aircraft.cfg I changed in the [Propeller] section...

Propeller_type=1

...and...

gear_reduction_ratio=1.25

I also changed the tach in the VC to the C172 tach which matches the 2D panel and redlines at 2700 instead of 2400.

The good side is these changes net a plane that behaves as if it has a fixed pitch prop that redlines about 2600 RPM in level flight at sea-level.

The bad side is the plane will not idle at anything below about 1/3 throttle.

So it's better, but not yet best.

peace,
the Bean

[mgh]

Entry 330 is probably redundant because it's now in .cfg file. According to Aircraft Airfile Manger:

330h=No more used since FSX and probably FS9 too.||For prior FS versions:|Till now decoded as propeller type. |1=Fixed|2=Auto Adjust|3=Manual Adjust||This interpretation may be wrong. CFS3 and FS9 use following parameters: ||0 = all FS9 jets|1 = Cherokee|2 = Extra 300, King Air, Dash 8|3 = Cessna 172, 182 and 208, Mooney ||no record = Baron, all FS9 historic aircraft, all CFS3 aircraft 3

[KCD]

Bean...

You are getting the same performance result I have gotten, tach will not move off the red line until about i/3 throttle and at that point, the engine sounds to be at about 1200 RPM. Thank you for your respones; you responded to my earlier posts on this subject to the FS9 forum over a year ago, so it is deja vu all over again. As you can see, I am anything but inconsistant. I'll keep trying and if you come up with an idea, please pass it along. I really want to fix this problem.


MGH...

Does your comment that "entry 330 is probably redundant because it's now in .cfg file" indicate that that the .cfg file entries overide the .air file"? According to your highlighted section, what would I try for "fixed pitch", a la J-3 cub?

KCD

[StringBean]

Bean...

You are getting the same performance result I have gotten, tach will not move off the red line until about i/3 throttle

No, I am not seeing that performance.

With the mods I made at full throttle in level flight at sea level the tach reads about 2600 RPM.

Pulling the throttle back causes the tach needle to go down, as you would expect with a fixed pitch prop.

As I posted above, sitting on the ground the plane requires about 1/3 throttle to idle. Anything less and the engine dies.

peace,
the Bean

[edit]
the key is the gear reduction parameter, the original entry of 2.3 spins the prop too fast. Changing it to 1.25 helped it greatly. You may want to play with that parameter a bit.
[/edit]

[StringBean]

Entry 330 is probably redundant because it's now in .cfg file. According to Aircraft Airfile Manger:

Saw that, changed it anyway.

Belt and suspenders.

Took longer to read your post and type a reply than it took to make the edit.

peace,
the Bean

[mgh]

MGH...

Does your comment that "entry 330 is probably redundant because it's now in .cfg file" indicate that that the .cfg file entries overide the .air file"? According to your highlighted section, what would I try for "fixed pitch", a la J-3 cub?

KCD

just set

propellor_type=1

in the .cfg file.

[KCD]

Bean,

I think I may have totally corrupted the *.cfg file over the last 18 months of tinkering. If you are getting a proper throttle response in flight, that is far better than anything I have been able to achieve. I am going to start over (clean download) and make your changes and see what happens.

Thanks you both (ean & MGH) for your input and help

KCD

[crazyturbo76]

Have you tried playing around with the rpm_friction_scalar settings? That might help your Cadet achieve the high RPMs at full throttle