[dave hopkins]

[AIRTHUG]

[dave hopkins]

[danmoser]

[AIRTHUG]

In a nutshell, fairings need a few things to work effectively. For example, the fairing needs to be longer than the width of the item it is fairing. Also, fairings tend to be very angle-of-attack dependent.

Look at streamlined down tubes. Look at the length vs the width. They also have turbulator strips to ease some of the angle-of-attack issues.

Now, look at a cross bar- look at the diameter of that tubing. Extrapolate how long an effective fairing would need to be. Are the cross-bar fairings in use today long enough? Not nearly. In fact, they add to the diameter of the cross-bar, requiring the fairing to be even longer to be effective! Talk about counter-productive!

Then there's the angle-of-attack thing. They don't have turbulators, so it is very important that the AofA is right now. The current x-bar fairings are "free floating" and are supposed to adjust to the proper angle in flight. First, since they don't hang down when there's no airflow, there is obviously some friction in the system. Second, if they really are adjusting in-flight, that means they needed to be off, and creating a force to realign them. That doesn't sound very aerodynamic to me.

Last- and this is most important because it's not theory or speculation- if they are so effective, it should be pretty easy to prove. I don't mean fly one, then fly the other, and speak to your perceptions. I mean side-by-side testing. Morningside would be a fun place to see this test.

If you've been reading the magazine, Wills Wing actually used the test vehicle to measure drag at various pitch angles and airspeeds... and they did this with and without cross-bar fairings. The fairings produced more drag at higher speeds, exactly the opposite of what is desired.

Please don't respond unless you can address the shape, angle, and/or proven effectiveness of North Wing's fairings.

I will say they LOOK pretty sweet... anyone that knows me knows I sometimes by things for that reason alone. I have no problem with people that have or want x-bar fairings... but I don't see how the current fairings out there could possibly be effective. Science and physics say they're not.

To be clear- I'm not saying FAIRINGS don't work... I'm saying the currently available cross-bar fairings don't work. It's a good idea, but it just hasn't been implemented well yet.

The UP Comet wasn't the first double surface glider... but it was the first to implement the idea in an effective way, and it changed how gliders look today.

[rallyant]

[jj colorado]

What I found regarding the fairings.

I have a F3-195 with the aero control frame. Enjoy flying it a lot on lighter wind days, and having a U2 & F3 is a great quiver.

As I fly in the rockies the option of a little better wind penetration sounded good so I bought some Northwing fairings and cut them down for the Falcon 3. They seemed to be good design with relatively free floating attachment. There is still some drag to allow them to move. They don't just flop and float in the airstream.

At first I thought they might have made an improvement as they seemed to be a little quieter when pulling in strong and diving the glider, but did not have any measureable data on it. The glider flew fine with them, but they were one more thing to check before hook in and they were more material to pack up in the glider bag. After reading the testing report in the magazine I decided to remove them and see if I noticed any difference.

I did. It is a little quicker to set up the wing and to get it packed into glider bag when done flying without the fairings.

Did not notice any noticeable difference in flying and didn't notice the glider being any louder when pulling in. So unless there is some data to induce me to try them again I'll likely keep the wing in current configuration and enjoy the looser fit in the glider bag and one less thing to mess with setting up or packing the wing. If someone wants a good deal on a set of fairings cut to fit a F3-195, PM me.

Very interested in a side by side F3 - F4 comparison, but IMO the F3 is a great handling wing that is a blast to fly on low to moderate wind days. With the streamline control frame option my F3 has pretty good penetration and provides great feedback. Enjoy the low rib count, light weight, and the ease to bank it up on a tip fast in a narrow thermal. When I want a wing with better wind penetration and glide the U2 is sweet in just about any conditions.

So I'm glad that the F4 is more focused on extending capabilities on slow speed performance, but it is not like the F3 had any issues.

[rallyant]

What's the reduction in drag for these smaller of x-bars?
What's the mathematical formulae for calculating the drag of a round object?

Just interested to see In numbers the improvement

[jj colorado]

Try this.

http://www.unicopter.com/1021.html

Other than a flat plate or a square tube a round object has the worst aerodynamics.

"Flat plate CD =1.28
Rectangle CD = 0.75
Round tube/wire CD = 0.5
Ellipse CD = down to 0.25 (varies depending on ratio of thickness to length)
Airfoil section CD = 0.10 to 0.04 (varies depending on section)
It appears that a streamlined shape having a 3/1 fineness ratio (NACA 0033) gives the best value of CD , namely 0.045"

I believe Wills or some other company put up some figures on the coefficient of drag for a round tube and compare it to various shapes for control bars to show how much difference that makes in terms of drag. Of course that all is based on perfect alignment with the relative wind.

You can spend a lot of time talking about what the optimal shape is, but in brief, anything is an improvement on a round tube. The question is how much of an improvement, at what speeds, and is it worth it in terms of cost/benefit. The downside is that having it mis-aligned can cause other problems, and you need to set it up just right every time you fly.

[TomGalvin]

[blindrodie]

[zamuro]

[Bateleur]

Maybe its too early for someone to compare yet but im really interested to hear what people have to say between the Falcon 4 195 and the new Airborne Fun 2 190?

One of these gliders will be on my buying list within the next year!!

[AIRTHUG]

Both are great. Your smartest choice will probably be which will you get better dealer support for where you live? I know we don't ever PLAN on needing parts... but when you need something and have to wait a week or more for the manufacturer to ship it to you, it sucks. If you have a Wills Wing or Airborne dealer in that area, that would make the choice a no brainer...

[Bateleur]

[AIRTHUG]

Is price a factor? How much is a US vs Ausie imported hang glider?

[Bateleur]

[Bondy]

That's surprising there would only be a 100 to 200 dollar difference for both imported gliders to SA. Here in Oz you'ld expect the local Fun would be substantially cheaper than the imported Falcon but they are both the same price, around $5200. If it costs over $1200 to send a Falcon over here does that mean a Fun would cost $6400 in the US, and why do I feel we're getting ripped off here

[Ed061]

[danmoser]

The shipping cost isn't the biggest factor.. the currency exchange rates have a much greater effect.
Aus dollar was trading at 0.65 US dollars just a few years ago... now it's about 1:1 with the Aus dollar trending slightly stronger over the last few months.
According to a quote I got, it's about $400 for shipping F2 from Oz to US.
Total cost to get a new F2 in US is approx. $5,100.
Similarly equipped Falcon 4 195 total cost would be just under $4,000.
NOTE: These numbers were based on ACTUAL DEALER QUOTES.. with all shipping, insurance, taxes, fees, etc... not just figures pulled from websites..
The market is dynamic .. things are bound to change.. no tellin' which way or when.