Caudron C.430 Rafale

[DennyA]

In addition to the Ryan today, we also got a 1930's French air racer! What a pleasant surprise!

Bluemesh (creators of the freeware Alphajet and that weird ultralight/raft combo) released a really detailed Caudron C.430 Rafale air racer today. The cockpit is beautiful, and the flight model feels good as well.









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Forgot to mention -- it's only about $10!

[YoYo]

Denny, not 10$ but 10€ what its a very nice price for sure.
I saw this Today, very nice model, agree! I think it was in FS2004 Century of flight.
On my list from now.

[K5083]

It is a lovely looking plane. Props to the devs for their courage in doing such a cool but specialized subject, and for the nice pricing.

It is fun to fly with the stock flight model, but it seems inaccurate and unfinished in some respects. I have tuned it a bit, as follows.

First, performance is a bit anemic and I see in the engines.cfg that the max rated hp is set to 120 hp and the per-cylinder displacement to 137.5 cc, whereas on the real plane these would be 150 hp and 158.2 cc. I corrected these and it seems to help a little.

Next, although the visual animation correctly shows the prop turning counter-clockwise as viewed from the cockpit, the torque and p-factor effects pull it to the left, rather than the right as it should. There is no rotation= line in its engines.cfg, so I assume that aerodynamically, the plane defaults to clockwise engine effects, even though the visual model shows the opposite. I tried adding a rotation=-1 line, and this produced the correct flight handling, but screwed up the visuals -- the prop now rotated clockwise, and the animation was screwed up. So, I deleted that line, went into the flight_model.cfg, and added a minus sign in front of all the engine-direction-related values in the [FLIGHT_TUNING] section (torque, p_factor, gyro_precession, engine_wash). Now it looks right and also veers right, and I'm quite happy with it.

A couple more things might still be fixed. The prop pitch is currently continuously variable rather than 2-position as original. It has a parking brake which I don't think it should, and ground handling seems a little too easy for a tail skid airplane. But I can work around all that, it's easy enough to just use two prop positions and to leave the parking brake off.

I have picked out my parking spot on the addon La Ferte Alais airport, where it is quite at home, as shown in this pic. A fun flight is from Angers, where the static replica of this plane is displayed, to La Ferte Alais to participate in the fly-in.

August

[Tom Clayton]

For the tail contact, look in the flight model file for the contact points. The first variable in each line defines what it is - wheel, scrape, etc. If MSFS still supports legacy systems like when it first came out, you should be able to use a "3" to make a skid point. The next three entries in each line are longitudinal, lateral, and vertical. The two main gear points should have matching x and -x numbers for the lateral, and the tail will be zero. If the first parameter is a "1," then there's your flaw - the sim thinks it's a wheel. Change that to a three. While you're there, if it is a wheel to start with, the 7th parameter will be the wheel's radius. Make that a zero.

If your brain is now mush, copy and paste the contact points into a PM and I'll have a look.

[K5083]

Thank you Tom, you're quite right; I've edited those parameters before. I think it is safer to just put in a very small value for the "diameter" of the skid, say 0.1 feet, rather than 0, but I have seen it done both ways.

August

[DennyA]

Any chance you can share the lines that need to be changed to address the performance?

As for the prop, the author addressed that on the official MSFS forum:

This is what I will explain in the Caudron 430 user manual. It is because of this pneumatic system that Helene Boucher died, on a go-around, the pitch of the propeller did not allow the plane to regain speed, the plane crashed. If we simulate this in flight simulator most of the simmers would complain. Because it would only allow one takeoff and one landing. Without this pneumatic system the piloting is easier and allows to make several stopovers. But there was no lever for the propeller pitch either.

It would be nice if there was an option, like with the Bleriot that has "flyable" and "you're crazy to get into this thing" versions.

[K5083]

Sure. These are just my tweaks, your mileage may vary, but:

In engines.cfg, [PISTON_ENGINE] section:
cylinder_displacement=158.2 ; was 137.5
max_rated_hp=150 ; was 120

In flight_model.cfg, [FLIGHT_TUNING] section:
p_factor_on_yaw = -3 ; was 3
torque_on_roll = -1 ; was 1
gyro_precession_on_roll = -1 ; was 1
gyro_precession_on_yaw = -3 ; was 1
engine_wash_on_roll = -1 ; was 1
gyro_precession_on_pitch= -1 ; was 1

Note, you can't just add these lines, you have to find the existing ones and change them.

Second note: I'm not sure that last one, gyro_precession_on_pitch, was a good idea to change. That is, I'm not sure whether the effect of gyroscopic precession on the pitch axis depends on direction of prop rotation. Maybe someone here knows.

Another edit that I found worth making is to go into each [FLTSIM.x] section of aircraft.cfg and change isAirTraffic from 1 to 0. If you don't do this, any random airport ramp that you visit is likely to contain more C-430s than were ever built in total!

That is very interesting about the prop pitch. It makes sense, but I agree with you that an accurate option would be nice. If we want to pretend that we are flying a restored airplane or a replica in today's world, I'm sure most of us would install a constant speed prop, and probably a tailwheel, too. So the plane as set up by bluemesh reflects that scenario pretty well.

August

[K5083]

Just quickly following up on my own prior post, I did a little reading and i think I was right to reverse the sign on gyro_precession_on_pitch. That does depend on prop rotation direction. What doesn't - in fact, what shouldn't exist at all, on a conventional single engine prop plane, is gyro_precession_on_roll. The roll axis shouldn't be implicated in GP because GP essentially just couples the 2 forces with axes perpendicular to the prop axis of rotation, i.e. yaw and pitch, and not roll, which is the same axis as the prop rotation. Still, to the extent that gyro_precession_on_roll isn't even a thing, it should do no harm to change the sign.

August

[Tom Clayton]

Second note: I'm not sure that last one, gyro_precession_on_pitch, was a good idea to change. That is, I'm not sure whether the effect of gyroscopic precession on the pitch axis depends on direction of prop rotation. Maybe someone here knows.

It was definitely prop-related in FS9 (I still have the Container docs for that one). In the current documentation, the line is listed in the table, but the sections that would explain it are blank.

If anyone is interested...
https://docs.flightsimulator.com/html/index.htm

You'll find the cfg docs under Content Configuration > Sim Objects > Aircraft.

[YoYo]

FYI. Good info for VR users and this Caudron 430.
Its an issue here of scale size cockpit in VR (you feel like a giant in the land of the lilliputs). I contacted with develper about this issue and... he will do patch for this so it's a great news.
The add-on is very nice, but this strange view makes it hard to fly.

[Snurdley]

This is a wonderful piece of work for a great price. I haven't seen a whole lot lately that I would buy, but this and the Ryan gives me hope.