Wow, a perfesser. He so smart.
Flying cars fall down. And they're noisy.
Can I be a professor at KIT too? It doesn't seem to take much.
Far from being a mere staple of science fiction, plenty of flying cars really do exist, we're told. But there's one problem: hardly anyone knows how to fly them. That's according to Professor Michael Decker of MyCopter, the personal helicopter project at German university KIT. Speaking at the Hitachi EU Science & Technology …
Flying cars fall down. And they're noisy.
Can I be a professor at KIT too? It doesn't seem to take much.
A bit like helecopters. And look how popular they are up in Aberdeen at the moment after another one splashed down in the sea.
And thats choppers being serviced on a regular basis (every day) by trained mechanics.
Who knows someone who has a rusty old clunker with bits falling off it? The kind that only get to see a garage when its MOT time and half of it needs replacing. Going to be messy.
Clearly you wouldn't park on top, you'd just dock outside your office. But this whole "personal flying machine to avoid congestion" is going about things the wrong way - congestion is caused by cars being much bigger than the load they carry, so just carry the load in something more efficient than a car, e.g. effective mass transit systems.
Or a smaller vehicle.
You could even suggest one with no tailpipe emissions, or one with no emissions at all...
(Excluding the driver of course)
"Over the hedge" (great kids film) has a lovely scene where the animals are gathered round an SUV - saying "wow, how many humans fit in *this*" to which the "knowledgable" animal replies:
"normally only one"
Or just get the computer to drive the car so it doesn't need multiple car-lengths of empty space in front of it just to cope with the distance it travels before the driver even realizes something has happened.
Getting tired of all those people wanting to computerise cars so that they travel as a train, with only a few feet between them. Yes, fine, when all the systems are synchronised so that all the systems brake and accelerate in the normal course of driving. However, when an accident happens e.g. tree falls on car, if there is no braking distance for the speed the vehicles are travelling at then you are going to have the mother of all pile-ups.
Computers may help resolve some of the problems caused by the meatbags travelling in them, but physics still rules (bitch).
I was thinking of having docking ports on the side of the building, and then thought that the cars could be stacked in 'carpark' quite efficiently.
I still like that advert with the waterslide - excellent way to get to and from work :-)
Fair point - you didn't say anything about high speed. It's just that so often futurologists give the image of a "train" of vehicles travelling on motorways at high speed with practically no stopping-distance between the vehicles that I guess I jumped straight to that meme. Town-speed, less of an issue except that repair bills for any prang are huge on cars that are designed to crumple so as to protect occupants - so proper stopping-distance between vehicles would still be a good idea.
You just push a button and it folds up into an attache case.
'so proper stopping-distance between vehicles would still be a good idea.'
And there endith the dream, of using drafting, to reduce fuel consumption.
Don't try this in NYC, where many of the building have or had helipads designed into them.
See, there was this incident when a rotor blade came off a helicopter sitting on the Pan-Am (now the Met Life) building rooftop helipad, showing a bunch of people on Park Avenue why we call 'em "choppers".
After that, helicopters were not allowed to land on skyscrapers any more.
Why the dig at the SUV? Goes for most cars.
Pile ups happen on the ground as well, whatever system is in place to manage lofty traffic would manage it far better plus there's the third spatial dimension to take advantage of!
Well, how many accidents happen due to a tree falls on cars while they are driving?
I am sure it happens but it will be a very small amount compared to all other accidents that computerization will solve.
You sound like someone who always looks why things will fail rather why they will work.
So we will solve 99% of accidents and you complain that about the 1% left?!
even better, WTF is the point of CBDs in this age where most communications are electronic, not physical ? Abolish those expensive tax breaks for the rich and move office spaces to edge of cities and maintain medium site densities. No need for lots of cars, flying or not.
Given the stresses on critical parts of flying vehicles of any kind are far higher than ground vehicles one wonders if hordes of flying cars will ever be safer than trains or cars. Lose a wheel and you usually just stop. Losing a wing or rotor has less benign consequences.
Adding a ballistic recovery chute opens a whole new can of disaster worms. A large chute blasting in front of traffic is not a fun way to fly. This is why meat bomber drops are called well before the jumpers leave their perfectly good aircraft so saner aviators can be out of the area.
re: Mass transit systems...
Like the railways I guess.... Lets start from somewhere you didn't want to start from and go to somewhere you didn't want to go to... Couldn't we just drop this ancient tech and appreciate the dawn of hybrid and ultimately electric cars and put a bit more effort into developing the infrastructure. Otherwise it's a huge step backwards... and no different from the Prof commenting on eliminating the drive to and from the airport if you can't take off from home and land at work or wherever...
You miss the point, get back in your x5 and continue making a fool and / or nuscance out of yourself...
Calm down dear.
People are not asking for cars to travel like a train, but just closer to each other than humans can cope with. At most speeds a significant portion of the braking distance is our reaction time.
NO ONE is advocating a system without large margins of safety. If a tree spontaneously materialised on the M25, such systems would be safer than human drivers, in part because cars a mile behind the incident will start slowing the moment it happens. You wouldn't have a huge pile up.
The nastiest crash in recent years (sudden loss of visibility due to a fireworks display) wouldn't have happened under this sort of system.
Physics do rule, but engineers have a better grasp of it than you do (twit)
"And there endith the dream, of using drafting, to reduce fuel consumption."
That one ended for me when Mythbusters proved you had to be within a metre of the vehicle in front to show a measurable advantage........and that was with a car following a truck(!)
And of course their science is unimpeachable! Ever noticed that any "myth" that would increase dangerous or illegal activity on the road is ALWAYS busted?
Anyway, doubtless they were using an American car with a massive engine that uses most of it's fuel just to keep the engine warm rather than actually moving the car so any saving was lost in the noise.
In my first car (knackered 1.1L Ford Escort Mk1) I used to tailgate lorries, it was the only way I could do 60 without having my teeth shaken out from the racket! From the reduction of throttle and engine noise it was significatly less work for the engine and I was a lot more than a meter from the lorries. Happliy my current car can do over a 100mph comfortably and other car has a V8 engine. :-)
> However, when an accident happens e.g. tree falls on car, if there is no braking distance for the
> speed the vehicles are travelling at then you are going to have the mother of all pile-ups.
Indeed. Much as you do when a train car derails. We treat that as an acceptable risk because it happens much less frequently than similar sudden-deceleration accidents happen with cars.
Cars suffer tire blowouts. They lose parts - I've seen cars in front of me on the highway lose hubcaps, mufflers, in one case a rear bumper. Have fun driving over that at 75 mph. I did some towing for a while, and once had to retrieve a Jeep that had lost an entire rear wheel - the axle was defective and had sheared. It was just luck that the driver was pulling slowly out of a parking spot and stopped as the body of the Jeep ran over its own wheel; a few inches further and he'd have been on only three wheels, which is not a tenable position for a Jeep. That would have made for a very nasty highway accident indeed.
Bumper-to-bumper travel at highway speeds has unpleasant failure modes. Anyone who's done the Route 128 commute around Boston knows that. Automating it doesn't help - not enough to be worth it.
If they are computer controlled (and frankly I'm not sure anything else is sane) then they can just fly off home until you need them in the evening - or to a local charging facility if they are electric
Totally agree, sending them back to base for recharge/checkup would not only mitigate the danger of unmaintained personal vehicles crashing through your roof but also mean all the vomit had been cleaned from your sky car when you were ready to return home.
Indeed, it seems that automatic operation is the route the US DOD are looking at for their 'flying jeep' concepts. Also, fully automatic operation means that cost of ownership can be shared amongst individuals - or the vehicle just hired by the minute. After it drops you off, it makes itself useful elsewhere.
However, if reducing congestion is the aim, car sharing would be a better first step- especially now most of us carry communication devices in our pockets that know where we are and can be used to bill us / share costs. I'm happy to share a vehicle with a couple of adults... its the hordes of sodcasting teenagers on busses that do my nut.
Also, saner legislation: A car protects you from the elements buts takes up twice the width of road required for just one person. BMW introduced a scooter with a roof and rollcage, negating the need for leathers, boots, gloves and a helmet. UK legislation insists that a helmet is still required for this machine, despite it being LESS safe than not wearing one, due to extra forces on the neck in the event of a crash.
Wrote : "they can just fly off home until you need them in the evening"
Great, you just doubled the fuel consumption.
Aren't the power requirements to fly somewhat more than they are to drive? Obviously driving has a certain amount of wastage as you can't go in a straight line to your destination (I expect this may be a slight problem in mass deployed air traffic scenarios too, particularly around cities), and you may have to queue at some point. A small single engined Cessna/Piper plane would get around 15-20 mpg while cruising (*) - no idea what it takes to get it off the ground, though - so I can possibly believe it's comparable to a "not so good" engine in a large SUV..VTOL stuff obviously use a shed load of fuel to go up/down, though.
I'm sure it'd be fun trying to fly to work at the various office/industrial estates around Heathrow, too, and you have to wonder how you manage lots of folks trying to land at around the same time at around the same place (e.g. stadium event, 9am in central London, shopping centres, etc...).
Who knows, perhaps the next phase of the Google driverless car will fix all these issues. I won't hold my breath, though.
(*) lots of variability due to wind influence and a whole host of other factors
You're spot on here; the power requirements for flying are a lot more than for moving an equivalent sized vehicle on the ground, so the "emissions" argument falls down straight away (not even considering that the majority of vehicles today don't use stop/start technology which would reduce the emissions of a ground vehicle to nil when it's stopped).
The cost of buying and operating one of these things mean that they're only going to benefit the rich; so only a very small proportion of the population and no solution to urban congestion.
If the professor wants to improve life in the 21st century, he needs to look away from crap ideas from early 20th century sci-fi.
"The cost of buying and operating one of these things mean that they're only going to benefit the rich; so only a very small proportion of the population and no solution to urban congestion."
I'm sure a similar argument was made against cars in the early days. "They are too expensive, so they will only benefit the rich."
Except, as more rich people buy them, more are produced, production techniques improve and economies of scale start to have an effect. Soon (although it could be decades) people on "middle" incomes get to benefit, and eventually even the "poor" can afford a second hand one.
As for the rest of your argument, andvancement of technology would eventually improve the performance and power requirements. This is also likely to be decades away, but none of your arguments are good enough to say "Why not do something usefull" to those developing these vehicles.
> stop/start technology which would reduce the emissions of a ground vehicle to nil
even better, use intelligent traffic control so that ground vehicles don't have to stop at junctions in the first place. If you're going to implement traffic control in the skies, try it on the ground first where its cheaper and safer.
"andvancement of technology would eventually improve the performance and power requirements."
Hmm - there's not much that can be done about the energy required to shift an object of a given weight up 100m or more. Aerodynamics is well understood, so unlikely airframes will get much more efficient. The infernal combustion engine has been around for a hundred years or so and is probably nearing the plateau of efficiency. Electrickery would be a good way to go as you can budget for economies of scale in generation. But generation is getting more expensive as the Greenies convince more governments that a big windmill is a good way to go (although it looks like that fad is winding down). Nuke is a nice idea, but I've not seen a convincing cost argument either way - too many biased authors. Cold fusion would be a delightful solution, but then we wouldn't care how many cars were knocking around as it would all of a sudden be cost effective to give everyone lots of choice of personal transportation - including diddy little mono-person carriers (with add-on pods?) for their commute. In 2010 it was estimated that there were 31million cars on UK roads - so pretty much one for every person with a license (DVLA reckons there are around 36M licensed drivers in the UK).
Yes, there are probably improvements to be made in current technology, but I fear it would take a technological leap to realise the dream of global accessibility to flying cars.
Just because most A/C achieve crap MPG figures doesn't mean that flight inherently requires more power than land transport. You need to consider:
1) The car's mileage is measured at a speed of ~50mph or so, the plane's is measured at ~100kts which is ~120mph. I challenge you to get much more than 15-20MPG from a car travelling at 120mph.
2) The example aircraft in your link (Cessna 172) was designed in the 1950s. Aerodynamics have come a long way since then.
3) The engine in that aircraft (Lycoming O-360) was also designed in the 1950s. Using 1930s car engine technology. Engine technology has come a long way since then. The brake specific fuel consumption of an O-360 is .43lb/hp.hr whereas a modern diesel car engine achieves 0.32lb/hp.hr i.e a 34% improvement in fuel consumption. More modern, efficient aircraft engines are available - but they generally only get put in new design aircraft.
Take a modern aircraft with a modern engine e.g Pipistrel Virus with a Rotax 912S as a better example. That combination achieves ~40MPG at a 135kt cruise i.e ~150mph! Doubt you'll beat that with a car...
But can they land vertically ? Yeah, I didn't think so. I wonder what the mileage is on a Harrier ? (Hardly a commuter vehicle, LOL).
JetSetJim wrote :- "VTOL stuff obviously use a shed load of fuel to go up/down, though."
Dead right there. VTOL, as advocated by the professor, is massively inefficient.
Any form of flight will have vastly greater power requirements than ground travel. This is because in order to fly, you have to overcome gravity (duh!).
Now gravity is a constant downward acceleration of 9.8 m/s/s. This translates, in carspeak, to 0 - 100 km/h (62 mph) in 2.8 seconds. That's right, the acceleration imparted by gravity is greater than that of any production sports car, and greater than that of most sports motorbikes. You show me any commercially available ground vehicle capable of 0-100 km/h in 2.8 seconds! Even if there is one that I don't know about, I'd wager its fuel consumption would be a strong discouragement to commuter use!
In order to fly, any vehicle must overcome this downward acceleration with an equivalent upward acceleration. That means consuming the equivalent power required to accelerate from 0-100 in 2.8 s constantly, every second it's in the air, just to hover or maintain altitude. If it needs to climb, it has to surpass this power consumption; that is, be able to achieve the equivalent of 0-100 in less than 2.8 s!
This is why even little Cessnas have the equivalent of a Dodge Viper motor under the bonnet. It's the reason why aircraft get such shitty per-litre mileage. It's why flying is such a major cause of emissions. And it's why flying vehicles en masse is completely impractical - because it will, no matter how efficient we make such vehicles, always consume much more power than ground travel, just to stay in the air.
I will wager that the modern diesel car engine weighs over 34% more than the O-360.
Sorry, you are wrong. Gliders do not fall out of the sky in the same way as a lead weight.
The maths behind it is vector based, taking into account weight, lift, drag and thrust. Paramotors (large parachute, pilot and a propeller) fly through the sky using a 50cc motor.
Sorry, I am right. You said it yourself: the lift <-> weight part of that formula is exactly what I'm talking about. The weight is the downward acceleration of 9.8 m/s/s imparted by gravity; the lift is the 9.8 m/s/s upward acceleration imparted by whatever means the aircraft is using to generate it, be that means air pressure along a wing surface, the displacement of a column of air by a rotor, the counterpressure of a jet engine, or the Newtonian thrust of a rocket.
A glider with zero forward velocity will fall out of the sky like a lead weight until it gains enough momentum to allow its wing surface to generate the equivalent lift required to counter the weight acceleration of gravity. However the craft does it, that 9.8 m/s/s downward acceleration has to be countered. That's basic high-school physics.
"This is why even little Cessnas have the equivalent of a Dodge Viper motor under the bonnet."
I think you'll find some small hatchbacks have more power than a lot of little Cessnas and the like.
The plane I learned to fly in had an almighty 145bhp and that was a lot more nippy than some of the others at the club. Stick that in a Viper, and it works out at bang on 100bhp/tonne, which is not exactly supercar territory. It's not even hot hatch territory.
Paris, because I'm sure she has a hot hatch with a few spurious fluid leaks.
I assumed the math was for VTOL hence lead weight. Gliders and normal A/C do not fit the bill of "flying car" in this concept - I assumed we were looking at helicopter equivalents (witha car component bolted on). Otherwise we are simply talking about helicopters.
"Take a modern aircraft with a modern engine e.g Pipistrel Virus with a Rotax 912S as a better example. That combination achieves ~40MPG at a 135kt cruise i.e ~150mph! Doubt you'll beat that with a car..."
I take your point about the fuel efficiency of an aircraft optimised for cruise efficiency; your example is a small 2 seater with a relatively long wingspan and good gliding performance. But a flying car will have to be optimised for STOL or VTOL and compact(ish) dimensions for parking, so a lot of the fuel-efficiency will be thrown out of the window.
"Now gravity is a constant downward acceleration of 9.8 m/s/s. This translates, in carspeak, to 0 - 100 km/h (62 mph) in 2.8 seconds. That's right, the acceleration imparted by gravity is greater than that of any production sports car, and greater than that of most sports motorbikes"
You've got the physics wrong here; when forces are in equilibrium there is no energy used, so the ground doesn't require any power to overcome the force of gravity when you stand on the ground.
An aircraft doesn't use engine power to defy gravity, it uses aerodynamic lift created by the small(ish) pressure difference between two sides of a large(ish) aerofoil (wing). The energy is used to push the aerofoil forwards against air friction, but that can be pretty efficient (gliders can use the movement of warm air to climb). conventional aeroplanes are pretty efficient, but "flying cars" have a lot of conflicting requirements (VTOL, compact footprint) that mean that fuel efficiency is not top priority.
Gravity is why a plummeting VW Beetle can beat a twin-turbo Porsche 911 over a mile.
In the words of Wolfgang Pauli, Das ist nicht nur nicht richtig, es ist nicht einmal falsch!
Imagine if the autopilot was designed by MS. The BSOD would take on a more literal meaning.
God these BSOD jokes never get old...oh wait. They do.
"This will actually fall down and you will fall and probably die"
Such a shame that this ringing endorsement of the flying car's safety credentials arrives just too late for Quote of the Week...
"Yes dear I'll drop your mother off on my way over."
"Honestly Persephone; you're six years old and you still can't pack a parachute properly."
"Probably just a piton tube, mate. I'll see if I've got an old one out the back."
"No officer the gates were locked. I've no idea how they got into the yard."
"Well have you tried scraping a Canada Goose off the windscreen?"
"Well the satnav said it was a field, not a reservoir."
"No sir, that bridge is 13 foot six, when you're on the ground."
"I don't care if there is a 747 coming. It's my right of way."
<-- "Good evening oshifer. Why are you standing upside down?"
That's "Pitot tube". And yes, the final t is mute.
And the oshifer one is pretty good. :-)
Does anyone believe that ?
For a helicopter !
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