Flying Cars Get OK From Department of Transportation

It may be one of those plastics that grow opaque as they age. It may not be strong enough. It may have worse glare problems. It may not resist chips and scratches as well.

Or it may simply not have been fully tested for the job.

Polycarbonate is not used widely because is VERY expensive to fit and replace. My glider canopy is $5000 replaced: http://www.mikeash.com/my_glider.html (ask me how I know).

Note even the canopy for the ancient but popular ASK-13 is over $2000 on this site: http://www.wingsandwheels.com/glider_canopies.htm

Installing these babies is really tricky. Nothing ever fits quite right from the factory. Worth another $3000 easy in labor; after all it is an aircraft.

It appears that there is no specific prohibition against polycarbonate windshields for cars. The exemption in this case is required because the polycarbonate windshields that Terrafugia currently uses do not pass the required abrasion tests: basically, they scratch too easily and are too prone to reduced visibility.

Terrafugia requested the exemption because it is still searching for a vendor that passes the compliance tests and meets the vehicle's unique requirements. Apparently, vehicles with the current windshields will be required to undergo regular and frequent inspection and repair.

See the page numbered 38273 in the PDF:

http://www.terrafugia.com/pdf/2011-16222_NHTSA_EXEMPTION_GRA...

CDs are polycarbonate and shatter sharp. Maybe there is polycarbonate that doesn't. Autoglass is required to shatter into slightly dull bits.

Pitting would likely also be a problem causing reduced visibility. Aircraft stay above most land blown grit.

"Why is polycarbonate not allowed for ordinary cars?"

Go to a parking lot and look at the plastic headlight covers on high-mileage cars. Many are frosted to opaqueness because of impact with grit.

(pilot) Probably wouldn't be significant. If you go walk around at an airfield you'll notice all types of similar imperfections on airplanes and they still fly perfectly fine and are classified as airworthy.

There are a few exceptions (propeller, cracks, etc...) but planes are a lot more forgiving to surface deformities than you would imagine.

...build cages instead of fences.

Cameras. Defensive tools (ie, guns) where it matters. Etc.

I doubt it'll be an issue for the same reason I doubt it's been a major issue that bolt / wire cutters are available in any hardware store. The physical barrier isn't the only thing that prevents people from crossing it and causing havoc.

I'm pretty sure the average person can easily rent a helicopter for a few hours. A Greek prisoner escaped that way, with a bit of help from his friends.

Never say never but, WRT nuclear power plants...

http://en.wikipedia.org/wiki/Containment_building

"In 1988, Sandia National Laboratories conducted a test of slamming a jet fighter into a large concrete block at 481 miles per hour (775 km/h). The airplane left only a 2.5-inch-deep (64 mm) gouge in the concrete. Although the block was not constructed like a containment building missile shield, it was not anchored, etc., the results were considered indicative. A subsequent study by EPRI, the Electric Power Research Institute, concluded that commercial airliners did not pose a danger."

WRT prisons, landing with an airplane is going to be challenging (minimum landing distance is 500m) and taking off is likely impossible (minimum take-off distance is 520m[1]). Given the improbability of leaving the prison, it will be a self-correcting issue. ;-)

[1] http://www.aircraftcompare.com/helicopter-airplane/Terrafugi...

The thing still needs a runway...

In order to use the Vehicle as a plane you still need to have at least a sport pilot license - which is kind of like a restricted pilots license. In order to get your sport license you need to learn, and are tested on, the airspace limitations that apply to all pilots. Those rules effectively stipulate* that you can't fly over a large portion of DC, including the White House, and should not fly or loiter anywhere near power plants, prisons, etc...

If you break those rules, even innocently, the FAA can come down hard on you by revoking your license and fining you thousands of dollars. Depending on how sensitive the area is and how suspicious you appear they can send other aircraft to your location and (in the case of the DC FRZ) potentially shoot you down. Once you've been indoctrinated into the system you learn to be extremely aware of where you are, what is nearby, and to stay away from sensitive areas.

*There are ways, at least for private pilots, to legally fly over a lot of restricted areas but it's much easier to just fly around them or not bother.

You might enjoy this: http://en.wikipedia.org/wiki/List_of_helicopter_prison_escap...

Especially this guy, who did it twice: http://en.wikipedia.org/wiki/Vassilis_Paleokostas

Have you seen http://www.popularmechanics.com/cars/news/vintage-speed/mave...? I think it is feasible.

...what? Moller got sued halfway to China, is bankrupt, and never shipped, and this is not Moller's car, nor does it use anything approaching the same design, nor does it share the same goal.

Moller's car was about making flying as easy as driving; this is about having a car that can turn into a convention aircraft. Or, more specifically:

Moller's car was based on duct fans; this is a traditional propeller aircraft.

Moller's car couldn't drive on roads; this is explicitly designed to (and is the aspect that was just approved, if you read the article).

Moller's car was designed to eschew traditional flight controls in favor of a do-what-I-mean approach; this aircraft has a completely normal yoke/rudder/throttle setup, where the yoke doubles as a steering-wheel in car mode.

Maybe this is the idea of Moller, in some very abstract sense, but I think you could make an equally strong claim that it was Jules Verne's ideas realized--and he never pretended to be trying to ship something.

Actually, this isn't really related. This is an exemption for the Terrafugia vehicles to use different materials than those required for standard cars and still remain "street legal." The Moller Skycar has never been planned to be a street vehicle, it is strictly an air vehicle.

Moller is an investment scam. The Moller skycar is a pretty fiberglass shell he's been hawking to magazines and television news programs for forty years. I'm amazed anyone still falls for it.