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The primary problem with flying things is that they currently rely on atmospheric lift. Loss of lift equals death of occupants and vehicle.

It's only when we transition to alternate means of lift that flying will be "safe" for public consumption and operation.



Lots of people fly currently and there is seldom fatal loss of lift.


There are safety measures such as autorotation and airframe parachutes that can safely land the aircraft after an engine failure.


And what happens when a Cessna parachutes onto the roof of your house? Onto the middle of a busy street? etc. If we were all using flying cars, this would become a regular occurrence. It's just not practical at that scale.


What happens when a car veers off the road into your living room?


Most roads don't point at people's living rooms. Now and then I see a house at the top of a T intersection, and I can't imagine living there. I used to drive down a country road that had nice houses a few feet from a curve in the road, so any car that didn't make the turn would hit the house. I would never live there, either.

But imagine hundreds or thousands of small aircraft flying over your house every day, driven by non-pilots, maintained like automobiles. I wouldn't want to live there, either.


The basic design of roads and their surroundings mean that an out-of-control car is relatively unlikely to collide with a building, as opposed to another car, a utility pole, a divider/barrier, etc. Conversely, an aircraft falling over a built-up area is very likely to encounter a building, and even if it lands in a road, it's going to be harder for moving cars to spot and avoid than an out-of-control car would be.


Probably much less damage, because a typical car in the city is going much slower than a typical plane falling from the sky, and kinetic energy goes with square of velocity...


A plane (with BRS parachute) falls at 10-20mph, according to BRS's website. Typically a small plane will weigh about 2000-3000lb.

A car in the city will be going at about 30mph, and will weigh about 4000lb.

There are news stories here regularly of cars driving into storefronts. Generally when I hear a story about a Cirrus activating their parachute, it lands on empty space and doesn't do any damage.


Any reason you couldn't add steering controls to an emergency parachute, just like skydivers use? Not manually pulled, but with some small emergency actuators? Basically you'd just need the ability to pull down corners of the parachute, right?


If the engine is still operating, you might be able to steer:

https://www.cirruspilots.org/copa/safety_programs/b/pull_ear...

(although obviously most of the times you would want to use the chute is because the engine has died!)


Maybe. But if you're making an emergency landing in a populated area, there is generally no safe place to land. Parachute or not, you're probably going to land on or in the middle of something, and injury or property damage is almost certain.

Whereas, if my car breaks down on the street...


Drop a 3,000 lb aircraft on a roof at 20 mph, and I think it will break through the roof.


Maybe not:

https://en.wikipedia.org/wiki/MythBusters_(2014_season)#Pian...

a 1400lb piano dropped from 50ft (40mph at impact) won't break through a roof.


Uh, yes it did. Did you read what you cited?

> A baby grand piano weighing 1,400 pounds (640 kg) pierced its legs through the roof but was unable to fully break through.

I consider the legs breaking through to be "breaking through the roof."

Then:

> Calling the myth busted, the team loaded another upright piano with enough sand to reach a total weight of 2,600 pounds (1,200 kg), much more than a full-size grand piano, then dropped it from 75 feet (23 m) above the roof. This time, the piano did smash a hole in the roof and landed on the floor.

Since we've been talking about a heavier aircraft, anyway, I hardly think this Mythbusters experiment proves anything here. As much as I enjoy watching the show, it's not a scientific study of how roofs are affected by heavy objects falling on them. There are a variety of factors to consider, including design, materials, condition, etc.

And finally, even if it didn't pierce the roof in any way, when it slid off the roof, it would land on something, damaging or injuring it.

The bottom line is that you don't want aircraft falling on your house.




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