Apr 3, 2006, 6:21 AM
Post #1 of 37
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Mylar ribs good/bad
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Both the Firebird and Phantom now give the option for mylar ribs. I honestly don't understand why you should want them.
They should prevent flapping but aren't you flying the suit incorrectly if you experience flapping?
With the S3S it helps with backflying but both suits can have/have back inlets, so that shouldn't matter that much.
The mylar ribs help inflate the wing for the first few seconds at a base jump, however I don't see why you want a wing profile when there is no wind to use it.
My experience(S3S) is that the ribs limit your movability and your range, they are also in the way when you pull.
So, if you buy a Firebird or Phantom, don't spend the extra cash when you're not sure you want them!
Both the Firebird and Phantom now give the option for mylar ribs. I honestly don't understand why you should want them.
They should prevent flapping but aren't you flying the suit incorrectly if you experience flapping?
With the S3S it helps with backflying but both suits can have/have back inlets, so that shouldn't matter that much.
The mylar ribs help inflate the wing for the first few seconds at a base jump, however I don't see why you want a wing profile when there is no wind to use it.
My experience(S3S) is that the ribs limit your movability and your range, they are also in the way when you pull.
So, if you buy a Firebird or Phantom, don't spend the extra cash when you're not sure you want them!
The only time they get in the way is when I put my rig in my gearbag and I have to actually "pack" the suit to ensure the ribs are not being bent out of shape.
As for functionality, I like the fact that when you pull the wing taut you get a nice and very strong airfoil shape. It almost feels like the fabric of an oldtime airplane wing. But, I'm no expert, and I'm interested to hear from people who actually know what they're talking about.
And while we're talking about design stuff that doesn't make sense, I don't get the wing deflectors... I've never seen any wing design with these types of deflectors. They puzzle me. What exactly are they for? To make the suit less prone to stalling by deflecting the airflow over the wing?
My experience(S3S) is that the ribs limit your movability and your range, they are also in the way when you pull.
With one whole jump, on a weekend where jumped about every suit that was available on the market and flew pretty shoddy in all of them because it was your 1st jump on them I wouldnt expect otherwise...
In no way were the ribs in my way when I pulled. Haven't heard from anyone else that there are either. Maybe you need to learn to fly the big wings first without adding ribs
With one whole jump, on a weekend where jumped about every suit that was available on the market and flew pretty shoddy in all of them because it was your 1st jump on them I wouldnt expect otherwise...
For your information I was flying "shoddy" because the suit was crap And I had 3(three) jumps on the S3S!!!
LouDiamond (D 25931)
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Apr 3, 2006, 7:35 AM
Post #6 of 37
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the option for mylar ribs. I honestly don't understand why you should want them.
Mylar inserts work in the same way crossbracing works in canopies, it creates a more rigid and effcient airfoil shape. This in turn relates to increased and better performance from the airfoil.
Quote:
I don't get the wing deflectors
These are quite simply known as vortex generators in the aviation industry, Google it and you will see many aircraft use them. In very simple terms, the longer you can keep the flow of air along the wing before it seperates(flow seperation), the more effcient it is in producing lift. Idealy you want this seperation to be as close to the trailing edge of the wing as possible. In order to facilitate that, the use of vortice generators literaly stirs the air up to keep the energy of the air moving along the wing and prevents it from stalling at high angles of attack.The vortices created by the deflectors interact with the rest of the air moving over the wing to speed it up and help reduce the possibility of separation. The deflectors you see on the S3S and S6 are and improvement on the older design of Skyflyer deflector based on the information gained from the wind tunnel testing Birdman did awhile back.
Mylar inserts work in the same way crossbracing works in canopies, it creates a more rigid and effcient airfoil shape. This in turn relates to increased and better performance from the airfoil.
I do not agree. Cross-braced technology is very different. The ribs are there to keep the topskin from a certain distance to the bottom skin. a non rigid rib will do the same job as a rigid rib and generate the same airfoil shape.
These are quite simply known as vortex generators in the aviation industry, Google it and you will see many aircraft use them. In very simple terms, the longer you can keep the flow of air along the wing before it seperates(flow seperation), the more effcient it is in producing lift. Idealy you want this seperation to be as close to the trailing edge of the wing as possible. In order to facilitate that, the use of vortice generators literaly stirs the air up to keep the energy of the air moving along the wing and prevents it from stalling at high angles of attack.The vortices created by the deflectors interact with the rest of the air moving over the wing to speed it up and help reduce the possibility of separation. The deflectors you see on the S3S and S6 are and improvement on the older design of Skyflyer deflector based on the information gained from the wind tunnel testing Birdman did awhile back.
Ah, ok... so I *have* seen them on aircraft. It's just that they're a *lot* smaller on aircraft, probably due to the higher speed of airflow over aircraft wings, right? Thanks for the explanation, Scott.
Well many in the aviation and canopy mfgring industry would say otherwise. The key here is DEFORMATION. Simply put, a rigid airfoil is more effcient than a non rigid airfoil and thus performs better.
Leading edge deflectors are derived from the (fixed) slots seen on some fixed-wing airplanes. Their function is to re-attach the airflow to the top skin. Most airplanes only need (have airflow through) their slots at high angles of attack. That is why many airliners only deploy their (movable) slats for landings (high angle of attack, low airspeed).
The most popular vortex generators are small blades (look at the vertical fin on a Twin Otter) or triangles (look at the leading edge of a Glastar or Soloy Turbine Cessna 207).
Slats and slots perform the same functions as vortex generators, but are built differently.
1. It does not improve pressurization 2. It does not help unless you are flying the suit efficiently, meaning you only see the benefit of mylar ribs when you flying the suit towards maximum performance. 3. It does not have the same purpose as the ribs on cross braced canopies. Mylar does not make the profile more rigid (in terms of the connection of top & bottom surfaces like the cross braced rib system does)
The advantages of mylar are: 1. It helps to keep the right profile of the wing on the first few seconds on BASE exits 2. It reduces the vibration of the trailing edge of the wings, which directly affects the flight characteristics. This is the primary reason of having the mylar.
If it does break, how long does it take to get it fixed?
I am waiting on a Firebird-R that I was able to get upgraded for free from the standard Firebird. I'm hoping it doesn't break after a few jumps. Anybody with any stories or comments on this?
Your post, and another before yours seem to assume that the ribs have a "time limit" before they break. That's not true. Having ribs just means you have to be more careful with your suit, particularly when packing your rig, storing the suit, and even sitting on the plane in some cases. I am not a big fan of ribs and wouldn't want them in my suit because I don't want to have to worry about breaking them all the time. When I pack the suit gets squashed all up under my rig, and at the end of the day I squash it all up in my gearbag. But that's just my preference.
Plastic is plastic. It will break if you deform it past a certain point, not after a certain # of jumps.
TomAiello (D 22400)
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Apr 5, 2006, 6:01 PM
Post #24 of 37
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It helps to keep the right profile of the wing on the first few seconds on BASE exits
But you don't have any wind the first few seconds that might use the wingprofile to generate lift. right?/reply]
On a BASE flight, it is possible for small fractions of seconds to be critical. By holding the wing profile, lift generation starts sooner (since the wing doesn't have to fully inflate and take shape before it can start generating lift).
The difference between starting to fly at 2 seconds and starting to fly at 5 seconds can be astronomical.
These are quite simply known as vortex generators in the aviation industry, Google it and you will see many aircraft use them. In very simple terms, the longer you can keep the flow of air along the wing before it seperates(flow seperation), the more effcient it is in producing lift. Idealy you want this seperation to be as close to the trailing edge of the wing as possible. In order to facilitate that, the use of vortice generators literaly stirs the air up to keep the energy of the air moving along the wing and prevents it from stalling at high angles of attack.The vortices created by the deflectors interact with the rest of the air moving over the wing to speed it up and help reduce the possibility of separation. The deflectors you see on the S3S and S6 are and improvement on the older design of Skyflyer deflector based on the information gained from the wind tunnel testing Birdman did awhile back.
First of all, sorry for the threadjack, but this thread seems to be somewhat resolved concerning mylar inserts. I still have a question about deflectors/vortex generators, though.
As you can see in this picture (photograph by Saskia Zegswaard), the 2 innermost deflectors seem to be inflated somewhat, but the rest are just sorta scrunched up and not really doing anything except creating drag, just like they are when I'm standing on the ground.
I'm wondering if my deflectors are doing me any good at all. The wingsuit is an early production model (I bought it off of Jussi of Bird-Man), and perhaps they hadn't finalized the deflectors, because these are made of very tough plastic, very different from the ones that Jarno has on his suit, for example. I was thinking perhaps the suit would be better off without the deflectors, and I could take them off.
What do you guys think?
Cheers,
Costyn.
Another cool picture from that jump here. Thanks Saskia, you rock!
It's just that they're a *lot* smaller on aircraft, probably due to the higher speed of airflow over aircraft wings, right? Thanks for the explanation, Scott. 
deform.JPG
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