HALO Approved for 2018

[Just_a_fan]

@jjn9128

As for debry being dangerous, the indy aero screen will stop all body parts, the only unknown is the wheel which like i said is very uncommon.

How can you assert that? We know nothing about the aero screen's mechanical properties. Will it stop a wheel? We don't know. Will it stop a front wing / or even just an endplate? We don't know. Will it stop a heave spring? Guess what - we don't know.

We don't know anything about the screen other than it looks good. That's it.

[NathanOlder]

Will the halo stop another car slicing a drivers head off ? Guess what....

[Just_a_fan]

The halo has a much better chance of keeping a driver alive in that situation than the aero screen will, yes. In every such situation? No, probably not.

[djos]

@jjn9128

As for debry being dangerous, the indy aero screen will stop all body parts, the only unknown is the wheel which like i said is very uncommon.

How can you assert that? We know nothing about the aero screen's mechanical properties. Will it stop a wheel? We don't know. Will it stop a front wing / or even just an endplate? We don't know. Will it stop a heave spring? Guess what - we don't know.

We don't know anything about the screen other than it looks good. That's it.

We know a lot about it actually, it's the same material used in the F16 cockpit which can handle bird strikes at 1,000 kph and not shatter. The FiA even fired a wheel at an F16 cockpit and it absorbed the energy and deflected the wheel without any issues at all.

[Just_a_fan]

We know a lot about it actually, it's the same material used in the F16 cockpit which can handle bird strikes at 1,000 kph and not shatter. The FiA even fired a wheel at an F16 cockpit and it absorbed the energy and deflected the wheel without any issues at all.

The aero screen is not the same as a full canopy. The big hole cut in the top to let the driver get in totally changes the way the screen can handle applied loads. I'm struggling to see why people on a technical forum don't understand this.

[Just_a_fan]

As for an "F16 canopy", this from a paper looking at ejection systems for F16s:

The F-16 canopy, as shown in figure 1, reference 2, is drape-molded to produce a
single piece, compound curvature shape. It is a three-layer laminate. The inboard, half-inch
thick layer is polycarbonate, created from military grade flat stock. The 0.050-inch thick inner
layer is polyurethane, which is used to bond the polycarbonate to an outer 1/8-inch thick layer of
acrylic. The canopy is bolted to a metal frame for the aircraft assembly. The U.S. Air Force
supplied 10 scrap canopies that were rejected following flight service. These canopies were
manufactured by TEXSTAR PLASTICS of Grand Prairie, TX, and by Sierracin Corporation of
Sylmar, CA. Surprisingly different properties were observed between the two manufacturing
sources; the TEXSTAR canopy could be easily cut with a saber saw, while the Sierracin unit
could not. The Sierracin material softened around the saw and "gummed" it up, which indicated
that softening occurred at a significantly lower temperature. The final full-scale canopy fracture
demonstrations were conducted with TEXSTAR units.

https://ntrs.nasa.gov/archive/nasa/casi ... 109968.pdf

So 10 canopies that had been in service with the US Air Force, originally sourced from two different manufacturers, exhibited "surprisingly different properties". Which type did the FIA use? Do they know? Would a different supplier make a difference in the tyre test?

[Jolle]

We know a lot about it actually, it's the same material used in the F16 cockpit which can handle bird strikes at 1,000 kph and not shatter. The FiA even fired a wheel at an F16 cockpit and it absorbed the energy and deflected the wheel without any issues at all.

The aero screen is not the same as a full canopy. The big hole cut in the top to let the driver get in totally changes the way the screen can handle applied loads. I'm struggling to see why people on a technical forum don't understand this.

from www.f22fighter.com/cockpit.htm :

"The F-22's canopy is approximately 140 inches long, 45 inches wide, 27 inches tall, and weighs approximately 360 pounds. It is a rotate/translate design, which means that it comes down, slides forward, and locks in place with pins. It is a much more complex piece of equipment than it would appear to be. The F-22 canopy's transparency (made by Sierracin) features the largest piece of monolithic polycarbonate material being formed today. It has no canopy bow and offers the pilot superior optics (Zone 1 quality) throughout (not just in the area near the HUD) and it offers the requisite stealth features. The canopy is resistant to chemical/biological and environmental agents, and has been successfully tested to withstand the impact of a four-pound bird at 350 knots. It also protects the pilot from lightning strikes. The 3/4" polycarbonate transparency is actually made of two 3/8" thick sheets that are heated and fusion bonded (the sheets actually meld to become a single-piece article) and then drape forged. The F-16's canopy, for comparison, is made up of laminated sheets. A laminated canopy generally offers better bird strike protection, and because of the lower altitude where the F-16 operates, this is an advantage. However, lamination also adds weight as well as reduced optics. There is no chance of a post-ejection canopy-seat-pilot collision as the canopy (with frame) weighs slightly more on one side than the other. When the canopy is jettisoned, the weight differential is enough to make it slice nearly ninety degrees to the right as it clears the aircraft."

The costs for a whole unit are 10X more then a halo, they are very very heavy and need additional air and safety measures (because of fumes), heat prevention and fragile for scratches etc. Plus, 4 pounds (around 2kg) at 350 knots is not a lot compared with the loads that the halo will be able to have.

Lets see what happens when Indy will crash test their solution.

[djos]

We know a lot about it actually, it's the same material used in the F16 cockpit which can handle bird strikes at 1,000 kph and not shatter. The FiA even fired a wheel at an F16 cockpit and it absorbed the energy and deflected the wheel without any issues at all.

The aero screen is not the same as a full canopy. The big hole cut in the top to let the driver get in totally changes the way the screen can handle applied loads. I'm struggling to see why people on a technical forum don't understand this.

True, however you questioned the capabilities of the material, I just provided an example of its capabilities in a properly engineered solution.

[Just_a_fan]

The aero screen is not the same as a full canopy. The big hole cut in the top to let the driver get in totally changes the way the screen can handle applied loads. I'm struggling to see why people on a technical forum don't understand this.

True, however you questioned the capabilities of the material, I just provided an example of its capabilities in a properly engineered solution.

Indeed so. The key phrase there being "properly engineered solution". I, along with others I'm sure, don't believe the Indy aero screen has been engineered to provide the levels of protection that the halo has been engineered to provide. Certainly, I don't believe the Indy-screen is intended to deal with anything more than bits of carbon bodywork flying about c.f. Justin Wilson's accident. I'm sure it will do an excellent job of that. Stopping a wheel at 150mph? No.

[djos]

The aero screen is not the same as a full canopy. The big hole cut in the top to let the driver get in totally changes the way the screen can handle applied loads. I'm struggling to see why people on a technical forum don't understand this.

True, however you questioned the capabilities of the material, I just provided an example of its capabilities in a properly engineered solution.

Indeed so. The key phrase there being "properly engineered solution". I, along with others I'm sure, don't believe the Indy aero screen has been engineered to provide the levels of protection that the halo has been engineered to provide. Certainly, I don't believe the Indy-screen is intended to deal with anything more than bits of carbon bodywork flying about c.f. Justin Wilson's accident. I'm sure it will do an excellent job of that. Stopping a wheel at 150mph? No.

That remains to be seen I guess, personally I think it'll perform much better than the FiA engineered to fail screen.

[Just_a_fan]

Why do think the FIA engineered their screen to fail?

[djos]

Why do think the FIA engineered their screen to fail?

Just look how thin the material is, looks more like thin plexiglass.

[NathanOlder]

The aero screen is not the same as a full canopy. The big hole cut in the top to let the driver get in totally changes the way the screen can handle applied loads. I'm struggling to see why people on a technical forum don't understand this.

True, however you questioned the capabilities of the material, I just provided an example of its capabilities in a properly engineered solution.

Indeed so. The key phrase there being "properly engineered solution". I, along with others I'm sure, don't believe the Indy aero screen has been engineered to provide the levels of protection that the halo has been engineered to provide. Certainly, I don't believe the Indy-screen is intended to deal with anything more than bits of carbon bodywork flying about c.f. Justin Wilson's accident. I'm sure it will do an excellent job of that. Stopping a wheel at 150mph? No.

But why does it need to stop a wheel at 150mph ? Its never happened. It could happen, but I've never known it to. This is an extreme example but, why not build the cars to withstand a helicopter crash, or an RPG round or hitting a tractor all are very unlikely, but all are possible. If you plan for something very unlikely, why not plan for all possibilities?

[Just_a_fan]

Why bother with an aero screen either then?

[NathanOlder]

exactly, I wouldnt bother at all. but if we MUST have something, then the Aero Screen all day long for me.