Maybe the flight modelling isn't that good after all?

[GoranM 3,762]

I lost a long post on I typed on my phone earlier. I try again.

 

After toying around in plane maker for a few weeks I do like the results. I was able to do a lot of tweaking to the default C172S, a type that I have about 80 hours in. I compared the data in plane maker to information in my POH, maintenance manuals and the table of equipment to get proper weight and balance, CG, and moment data.

 

I did run into a lot of difficulty trying to get specifications for a 7660 prop, so I left that alone. The various wing airfoil data needed a small amount of tweaking, but in all probably could have been left alone. I did make sure I matched up Reynolds number.

 

It now behaves fairly well by the numbers and allows me to perform most maneuvers using the same techniques I use in RL. It is evidence that the X Plane software does a fairly good job at flight modeling when presented with good data. Once you are up in the air and flying, the sim shines.

 

The plane would experience a dramatic improvement in realism if the default was replaced with one that had custom ROG. Most of the other tweaks could be made in about 5 minutes for a little better behavior during soft field takeoffs, slow flight and slips. I found the elevator was a little too large and therefore too effective.

 

Now here is where I get frustrated. No matter what I do, the airplane can't takeoff or land in a crosswind in a realistic fashion. no one has been able to come up for a solution to this as far as I can tell and it is a shame.

 

A 5 knot crosswind without shear from the right will readily weathervane the aircraft as soon as the brakes are released with the engine at idle. I have to use a lot of left rudder to stop the plane from turning right. taxiing is a real chore. during takeoff I have to hold just as much left rudder and then abruptly change to neutral rudder as the Mains come off the ground. I'll excuse the lack of P Factor for more, though I would like to know if there is a way to influence P Factor.

 

I haven't figured out a way to address this weathervaning by tweaking the plane in plane maker even by making unrealistic adjustments to the ROG, fuselage CoD, etc. it really hurts the sim, but out would be a really big deal (for me at least) if a default aircraft addressed this.

 

this does put the wrong foot forward and I believe that it has to turn people off, even those that are willing to spend several weeks of evenings playing around with the program.

 

You must be missing something. I've made a single engine GA, a twin engine GA, twin engine turboprop and a DC-3 and they don't experience excessive weather vaning at all.

If you're getting too much weather vaning, check if your rudder ROG is too high. I'll be willing to take a look at the acf file if you want to send it to me.

[GoranM 3,762]

Numerous times on an RV builders forum, someone has asked about a desktop sim for a Van's RV. Someone will say that X-Plane is suppose to have the best flight dynamics, and will go on to say that the sim includes some RVs with the program. I always have to step in at this point! The default unpainted simplistic RV's are not only ugly, but fly like crap. I can't believe they're still included (note: I think they're in XP10, but haven't looked lately). If someone really wants to see a good flying representation of an RV, then the Baytower RV7 for FSX fits the bill perfectly. Looks and flies just great!

 

So..........that's the point isn't it? I've already mentioned that a good portion of pilots are not really that familiar with desktop flight sims. And when someone asks on a pilot forum.........and is then directed to something like the included RVs with X-Plane.........because of what they've heard

 

Then, it isn't good for X-Plane, or Van's

 

L.Adamson

 

Did you tell your friends to look at Tom Kylers Falco. I remember you mentioned that it flies remarkably close to a Vans and is VERY accurate.

[LAdamson 240]

Did you tell your friends to look at Tom Kylers Falco. I remember you mentioned that it flies remarkably close to a Vans and is VERY accurate.

 

I've mentioned it numerous times.

[WarpD 824]

Not to detract or anything... but I saw "look at Tom Kylers Falco" and thought about when you go to buy a car... "Did you look at the Chevette? It's remarkably close to the Jetta in gas mileage and the body assembly is VERY accurate".

 

Just was amusing to me... that's all.

 

And yes.. I really had something that absurd happen to me when looking for a new car once.

[GoranM 3,762]

Not to detract or anything... but I saw "look at Tom Kylers Falco" and thought about when you go to buy a car... "Did you look at the Chevette? It's remarkably close to the Jetta in gas mileage and the body assembly is VERY accurate".

 

Just was amusing to me... that's all.

 

And yes.. I really had something that absurd happen to me when looking for a new car once.

 

Words cannot describe you, Ed.

[Alec 370]

I lost a long post on I typed on my phone earlier. I try again.

 

After toying around in plane maker for a few weeks I do like the results. I was able to do a lot of tweaking to the default C172S, a type that I have about 80 hours in. I compared the data in plane maker to information in my POH, maintenance manuals and the table of equipment to get proper weight and balance, CG, and moment data.

 

I did run into a lot of difficulty trying to get specifications for a 7660 prop, so I left that alone. The various wing airfoil data needed a small amount of tweaking, but in all probably could have been left alone. I did make sure I matched up Reynolds number.

 

It now behaves fairly well by the numbers and allows me to perform most maneuvers using the same techniques I use in RL. It is evidence that the X Plane software does a fairly good job at flight modeling when presented with good data. Once you are up in the air and flying, the sim shines.

 

The plane would experience a dramatic improvement in realism if the default was replaced with one that had custom ROG. Most of the other tweaks could be made in about 5 minutes for a little better behavior during soft field takeoffs, slow flight and slips. I found the elevator was a little too large and therefore too effective.

 

Now here is where I get frustrated. No matter what I do, the airplane can't takeoff or land in a crosswind in a realistic fashion. no one has been able to come up for a solution to this as far as I can tell and it is a shame.

 

A 5 knot crosswind without shear from the right will readily weathervane the aircraft as soon as the brakes are released with the engine at idle. I have to use a lot of left rudder to stop the plane from turning right. taxiing is a real chore. during takeoff I have to hold just as much left rudder and then abruptly change to neutral rudder as the Mains come off the ground. I'll excuse the lack of P Factor for more, though I would like to know if there is a way to influence P Factor.

 

I haven't figured out a way to address this weathervaning by tweaking the plane in plane maker even by making unrealistic adjustments to the ROG, fuselage CoD, etc. it really hurts the sim, but out would be a really big deal (for me at least) if a default aircraft addressed this.

 

this does put the wrong foot forward and I believe that it has to turn people off, even those that are willing to spend several weeks of evenings playing around with the program.

 

That great that you're trying to make X-Plane better as well! Hope you can soon make that file available for us to try the improved C172. Maybe even I will start messing with X-Plane a little bit, already did with scenery, but Aircraft is where I really want to try now. Just have to find some tuturials

[Oracle427 45]

I'm getting pretty comfortable with the modifications I've made. I must admit that I decided to work off of someone else's C172 as my starting point.

 

http://cbpowell.wordpress.com/2010/09/04/modified-cessna-172-model-for-x-plane/

 

So I must give credit to Chris Powell as this started as out with his aircraft. I have not annotated my "version" so I wouldn't want to have this one floating around the net and giving him bad credit. :)

 

What is the best way to send you the .acf and .afl files GoranM?

[MdMax 233]

I'm getting pretty comfortable with the modifications I've made.

 

Great news ! :good:

[Oracle427 45]

I didn't say this in my last post, so let me be clear in saying, that I have still been unable to do anything about the weathervaning and I still find it very annoying. Planemaker is fun to use.

[GoranM 3,762]

I'm getting pretty comfortable with the modifications I've made. I must admit that I decided to work off of someone else's C172 as my starting point.

 

http://cbpowell.word...el-for-x-plane/

 

So I must give credit to Chris Powell as this started as out with his aircraft. I have not annotated my "version" so I wouldn't want to have this one floating around the net and giving him bad credit. :)

 

What is the best way to send you the .acf and .afl files GoranM?

 

Check your inbox.

[Oracle427 45]

You have the controls...