# HoverCars are here! Don't crash! **URL:** \ **Category:** Factual Questions\ **Created:** [April 19, 2005, 5:27pm UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091 "2005-04-19T17:27:08Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![SCSimmons](https://avatars.discourse-cdn.com/v4/letter/s/e495f1/32.png) [@SCSimmons](https://boards.straightdope.com/u/SCSimmons)\ **Post date:** [April 20, 2005, 2:29am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/41 "2005-04-20T02:29:18Z")
Ooh, and I hadn’t even seen this gem: > [@Paul Moller](#): > > Moller says the ride could be described as mystical. But when is this vision going to be real? “Somewhere between 10 and 15 years, you’re going to see numbers of these vehicles out there being used,” says Moller. “First, you’re going to see them well before that in a military, paramilitary, police, **drug addiction** , border patrol type of capacity.” (As **malden** said, emphasis mine.) :dubious: Shouldn’t that be a ‘drug addiction _in_capacity’? ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [April 20, 2005, 2:41am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/42 "2005-04-20T02:41:24Z")
> [@Tuckerfan](#): > > Well, first of all, there’s a _lot_ of room in the sky, so you’re not going to have to worry about anything like gridlock, especially since there’s _not_ going to be a lot of people buying those things (not at $50K a pop, anyway). And I don’t doubt that the aircraft will use the radar with which they’re equipped to keep the pilot/driver from slamming into building or other object. Actually, there’s not a lot of room in the sky. In fact, there is very little, when we’re talking about commuting. Airports become congested when there are only a few airplanes in the sky at once. Yes, there is a lot of sky out in the boonies, but when everyone is heading for the same subdivision or downtown, it will get real crowded, real fast. The main reason the sky isn’t so big is because aircraft need a lot of separation. They wander all over the sky. Air currents rise and fall, winds gust, pilots aren’t that steady… That’s why aircraft need thousands of feet of separation between them. This is the major problem with ‘cars in the sky for everyone’. If even a tiny fraction of the population of a big city had flying cars, it would be raining metal as they run into each other. Either that, or there would be so many delays that no one would get anywhere. The road in front of my office building probably moves more cars in an hour than the entire city could move airplanes in a week. Aircraft also suffer the same problem as mass transit - you can’t pick up milk on the way home, or pick the kids up from school or drop them off at the baseball field. The thing is, ‘commuter aircraft’ are here today. Have been for decades. You could buy a personal helicopter from Rotorway in the 1970s’. There are ultralights that will take off in 100’, fly at 30mph, and land in 100ft. There’s even a sport pilot rating you can get for local flying that doesn’t take that much effort or really cost that much (compared to the cost of a ‘flying car’). The reason they aren’t in widespread use is exactly what I said: they need too much space to allow them to be packed into congested areas, so you have to drive miles out to the airport or a field. You can’t rely on them for commuting, because high winds, rain, fog, snow, and ice can ground them for days or even weeks at a time. They burn more gas than a car, they’re more dangerous, you tend to get your office clothes dirty doing a walk-around, and in general they make very little sense as commuter vehicles, except for the rare person who needs the particular qualities an airplane can give him. Adding hover capability to an airplane does nothing to relieve these liabilities. All it does is remove the need for about 1000’ of flat ground. > [@](#): > > Also, as Dean Kamen found out when he invented the Segway, there may, in fact, already be laws on the books, prohibiting the use of these vehicles in densely populated areas. There are. Every major city is sitting under a TCA, and there ain’t no way you’re going to get permission to tool around a congested area in controlled airspace in your puddle jumper. Ask all the millionaires who have multi-acre estates and would just love to land their Bell Jetrangers there, but are forced to use the airport instead. > [@](#): > > _If_ this does pan out, one thing that I hope is done with them is that they are used by police and ambulance services. Why would they want to do that? They already have helicopters. > [@](#): > > In many cities traffic is so bad that it’s difficult for emergency vehicles to get to where they’re needed even with the lights flashing and drivers trying to get out of their way. This technology could potentially save a lot of lives (since in many places within a city, you can’t land a helicopter because of the risk of wires catching in the rotors). And flying cars don’t run into wires and light standards? If cops start landing these things like patrol cars on freeways, there will be a lot of cop funerals. Flying cars are the dream that never dies. They’ve been ‘right around the corner’ for the past 50 years. There’s even been a certified roadable airplane with removable wings (The Taylor Skycar). But the problems aren’t just technical - they’re systemic. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [April 20, 2005, 2:53am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/43 "2005-04-20T02:53:55Z")
> [@Loopydude](#): > > That certainly appears to be true of the SkyCar. > > But (maybe our doper aviators can correct me if I’m wrong), supposing the rotors on the AirScooter are massive enough, even if the engine quits, they might have enough inertia to keep spinning long enough and rapidly enough to allow a survivable descent, so long as the thing isn’t too high up. If the propellers are variable-pitch and have a clutch, and if they have enough mass, then it would theoretically be possible to auto-rotate to a safe landing from certain parts of the flight envelope, but probably not all. Don’t count on it in this thing. Very light helicopters have issues around this. The [Mini 500](http://www.aircoinc.com/mini-500-helo.html) is a death trap in part because it’s extremely difficult to land if the power fails. I believe the Robinson R-22 had some problems in this area as well. Maybe **Johnnie L.A.** will be along to add to this, since he flies fling-wings. Cheap personal rotorcraft are not new. Rotorway has been making them for a long time, and they used to be quite cheap. The **Bensen Gyrocopter** has been around since the 1950’s, and you used to be able to buy them for just a few thousand bucks. They’re not a true helicopter, but with a pre-rotator driven by the engine, they could take off in something like 25 feet and land in about the same space. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [April 20, 2005, 3:00am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/44 "2005-04-20T03:00:54Z")
> [@Loopydude](#): > > Seriously, what if this [Moller](http://www.moller.com/) guy actually produces something other than vaporcars, and he’s got a commercially-viable model for sale. It would cruise at 200-300MPH, miles overhead. It could travel hundreds of miles. It weighs over a ton. It sure doesn’t look like an ultralight to me. What is it, effectively? A plane? A miracle. Moller’s numbers don’t add up. His fuel consumption figures are nuts. His top speed estimate is crazy. The front engine nacelles are perfect for picking up FOD (crap on the ground) and blowing it through the fans in the back, taking out one whole side of the aircraft. He claims that it can fly with a nacelle failed, except he hasn’t made full-feathering fans. The thing looks unstable under power, and would probably need active computer stability. Do you know what kind of regulatory hurdles he’d have to go through to certify that thing? Porsche spent tens of millions certifying their engine alone, and it was just an evolutionary adaptation of their car engines. The Moller Skycar’s LEAST radical feature is the fact that it uses a whole array of Wankel rotary engines driving ducted fans. It’s a pipe-dream. To answer your question seriously, I think his skycar would force a new regulatory category. ---
**Author:** ![DougC](https://avatars.discourse-cdn.com/v4/letter/d/7feea3/32.png) [@DougC](https://boards.straightdope.com/u/DougC)\ **Post date:** [April 20, 2005, 3:19am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/45 "2005-04-20T03:19:27Z")
- - - (sigh) Not this again. … - The problem with the concept of selling personal flyng machines like cars is that product liability lawsuits are what killed the US light aircraft industry/market during the 1970’s and '80’s, not lack of desire. In the US, private light aircraft ownership is down to something like less than 10% of what it was in 1955. The sad fact is that as it stands, anyone who buys an airplane and then has an accident in it can drag the manufacturer into court no matter how untrained they were, how poorly or improperly the aircraft was maintained or how bad the weather was they tried to go flying in. I recall an article that said one major company got sued 204 times between 1982 and 1986–and in _every case_ either they won or it was dismissed–but each case cost the company an average of $550,000. As aircraft companies closed down, parts for their existing planes couldn’t be obtained, and those planes had to be junked because they couldn’t be maintained properly. Consumer advocates please take note: the US light aircraft industry has almost been sued totally out of existence. - The products of what few light-aircraft companies are now left are ALL fantastically overpriced, in order for companies to budget for huge liability warchests and still turn a profit. At $50K, is the Aircar cheap? No. It is about equivalent in engine type and weight to a motorcycle, and motorcycles sell for a lot less than $50,000. - And finally, **Moller hasn’t produced anything**. He has been “seeking investors” and selling “information packets” for literally decades now, at least since the 1960’s. He does not sell aircraft, he sells “information packets”. ~ ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [April 20, 2005, 3:43am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/46 "2005-04-20T03:43:26Z")
Does anyone remember the [SoloTrek](http://www.solotrek.com/devhistory.html)? This thing generated just tons of breathless hype a couple of years ago. The guy who operates the company, one Moshier, has been creating great looking graphics and models of futuristic vehicles that were in ‘final development’ for decades now. And you too can buy the info-kit for $30, the video of the ‘flying prototype’ for $50, the T-shirt for $20, reserve a spot on the waiting list for $100, etc. ad nauseum. As soon as the hype dies down, the vehicle runs into ‘unanticipated delays’, and nothing more is heard until everyone forgets about it. Soon enough, another new miracle vehicle appears… People never learn. The sad thing is that there are a lot of great companies out there like [Van’s Aircraft](http://www.vansaircraft.com/) making affordable aircraft with spectacular performance, but the mainstream media doesn’t care about guys like that because the aircraft isn’t futuristic enough. Never mind that he’s sold thousands of his kits, and they could easily become one of the most numerous aircraft in the sky over time. But most people have never heard of them. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [April 20, 2005, 3:58am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/47 "2005-04-20T03:58:50Z")
> [@DougC](#): > > - > - > - (sigh) Not this again. > … > > - And finally, **Moller hasn’t produced anything**. He has been “seeking investors” and selling “information packets” for literally decades now, at least since the 1960’s. He does not sell aircraft, he sells “information packets”. > ~ To be fair to Moller, he does do real engineering. He has built hovering aircraft that do fly, he builds engines, and there’s some good engineering in some of his stuff from what I can tell. I believe he’s a professor of engineering, and does know his stuff. I think he’s also sincere about wanting to get the Skycar flying. That’s what makes it doubly difficult to figure him out. I put him in the ‘crazy inventor’ category, like those guys who spend their entire lives working on exotic, rube-goldberg cars, strange houses, etc. He’s so close to the hardware that he’s lost the ability to step back and see the big picture or something. But you know, a lot of the pioneers in various fields are slightly batty, and a lot of them work on things that are horribly impractical in their time. ---
**Author:** ![abby](https://avatars.discourse-cdn.com/v4/letter/a/48db29/32.png) [@abby](https://boards.straightdope.com/u/abby)\ **Post date:** [April 20, 2005, 6:26am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/48 "2005-04-20T06:26:12Z")
> [@Sam Stone](#): > > … a death trap in part because it’s extremely difficult to land if the power fails. I believe the Robinson R-22 had some problems in this area as well. Nah. I fly Robi-22’s, and they autorotate to landing just fine. Maybe back in the 80’s when they were first made? Don’t think so tho. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [April 20, 2005, 6:32am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/49 "2005-04-20T06:32:43Z")
> [@abby](#): > > Nah. I fly Robi-22’s, and they autorotate to landing just fine. Maybe back in the 80’s when they were first made? Don’t think so tho. Wasn’t there a handling issue with R-22’s not that long ago? I seem to recall the FAA looking at them because of high fatality rates. What was that about? ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [April 20, 2005, 10:40am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/50 "2005-04-20T10:40:15Z")
> [@FlightlessBird](#): > > [First off, How cool is this?!](http://www.cbsnews.com/stories/2005/04/15/60minutes/main688454.shtml) And the best part, is that it’s affordable and available within the year. Affordable is $50,000 and for a _FLYING MACHINE_, I’d say it’s affordable. I almost bought a Piper Warrior last year for $41,000. It’s a flying machine. Better yet, it’s a flying machine that actually _flies_, right now. Piper Warriors and C-172’s - basic, four-seat airplanes - can both be obtained for under $50,000. C-150’s - a two-seater - for under $30,000. Granted, those are the prices of used aircraft but I’m talking about aircraft that have been adequately maintained and are in good condition, aircraft that you could safely fly home in after handing over your money and being given the keys. Financing is obtainable from any number of places. Of course, you can pay _more_ than that for a newer one, or one with the latest panel-mounted GPS units (those can cost tens of thousands of dollars in and of themselves). But you can get a flying machine _right now_ for your $50,000 or under. > [@](#): > > And available within the year is according to the inventor on the radio this morning. \>sigh\< So many people have made statements like this for so long that my only reply is now “Uh, yeah - I’ll believe it when I see it” > [@](#): > > NASA has developed “The Highway in the Sky” system to allow everyone to fly their personal flyers in the sky without crashing. According to the 60 Minutes piece, and again the radio interview this morning, He equates the system to a video game and all you have to do is avoid the other cars on your screen. > > Um, does this concern anyone else? Assuming all hovercars equipped with this technology will show up on your screen, and it’s a clear day anyway, wouldn’t there be a number of vehicles where we will need something more? (maybe an infra-structure of where you can and can’t fly,like streets in the sky.) > > Am I missing something? Yes, but it’s probably because you’re not a pilot. Frankly, the whole tone of the article you linked to was a tad insulting to those of us who are _already_ flying and somehow, even without the gee-whiz technology, manage to avoid banging into each other. This isn’t rocket science. Oh, wait, maybe jets _are_… well, I fly piston-powered craft and those _definitely_ aren’t rocket science. Learning how to fly safely is what ground school and flight training are for. Now, the dirty little secret is that MOST humans beings are _capable_ of learning to do this… but most are not motivated to do so. The whole “highway in the sky” concept has been in development for a few years. And it holds great promise. It is also an example of technology-worship of the worst sort. As an example, last Sunday I rode shotgun in a Mooney airplane equipped with a Garmin 400 panel display with GPS and all sorts of other pretty technology. If you saw the X-man movie with their airplane and the neat-o color panel display… THAT’s more or less what I’m talking about. Very, very nice. Draws a line in the sky and you follow it. Only one problem: our GPS failed. Yes, they DO fail sometimes. In this case, it didn’t fail _entirely_, just in a couple features, but think about that – if the panel goes dark you KNOW there’s a problem. If only one or two things are wrong… would you know? WE knew because, out of long habit, we double-check everything and noticed the discrepancy. If our hypothetical Joe Six-Pack was in the same situation, _would_ he notice, and if he did, would he have the capability to determine what is right and what is wrong with this picture? To add further insult to injury, we were very close to a TFR (temporary flight restriction) zone. The US government accepts no excuse for trespass in these cases, they WILL send a “sky cop” after you. Which isn’t that different from being pulled over by a state trooper, except state troopers don’t have a machine gun mounted on their cars, nor to they carry heat-seeking missiles. Sky cops do. Now, being fully competant citizens of the air, we were able to revert to paper maps and the old Mark I eyeball to prevent infractions of the law and safely reach our destination. If we had not, however, our GPS would have carried us right across the heart of the Forbidden Zone. The moral here? _Technology doesn’t alway work._ No matter how modern and up-to-date. Why do accidents happen? Three reasons: 1. Things break 2. People make mistakes 3. Only God controls the weather In pilot training you are taught to avoid bad situations, and compensate (when possible) when they happen anyway. Even if the government didn’t require “full” private pilot licenses to operate a “flying car”, if they come into mass use there will HAVE TO be some sort of licensing, just as we have with cars and motorcycles to keep the carnage anywhere near acceptable. I’d like to go through the linked article, but that may have to wait since I do have to show up to work today - something about them paying me to be there on time and on a regular basis. 😉 Anyhow, I’d also like to address a few other points brought up, which I’ll probably do in bits and pieces, so bear with me. My life interferring with my hobbies again and all that 😃 ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [April 20, 2005, 10:49am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/51 "2005-04-20T10:49:07Z")
> [@Tuckerfan](#): > > Well, first of all, there’s a _lot_ of room in the sky, so you’re not going to have to worry about anything like gridlock Oh, Tuck, do please come flying with me in my neighborhood on some sunny summer Sunday… there is not so much room as you think. The skies over Chicago can look like the freeway at rush hour - except everything is moving faster and _can’t_ slow down. Airplanes require greater separation space than cars do. > [@](#): > > especially since there’s _not_ going to be a lot of people buying those things (not at $50K a pop, anyway). Uh, yeah - that explains the very few SUV’s you see on the road… hey, wait – Nope - there’s a market for $50,000 vehicles. Definitely. Which is why you see 'em on the road frequently. > [@](#): > > And I don’t doubt that the aircraft will use the radar with which they’re equipped to keep the pilot/driver from slamming into building or other object. Airplanes have radar? OK, _some_ do - but not the ones I fly, and probably not these “flying cars” either. There are also issues with use and maintenance of radar, which can (and sometimes have) caused injury to ground personnel when activated during maintenance. Which can add a whole new wrinkle. That said - someone IS working on a system to provide affordable terrain warnings to small aircraft, and even provide a mechanism to turn the aircraft away from obstacles. Of course, an override is necessary so you can land the aircraft at the end of the trip. > [@](#): > > Also, as Dean Kamen found out when he invented the Segway, there may, in fact, already be laws on the books, prohibiting the use of these vehicles in densely populated areas. Indeed. When I get to dissecting the article I’ll even mention some of the existing rules and how I think they’d apply to the various aircraft. ---
**Author:** ![Pushkin](https://avatars.discourse-cdn.com/v4/letter/p/ee59a6/32.png) [@Pushkin](https://boards.straightdope.com/u/Pushkin)\ **Post date:** [April 20, 2005, 11:43am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/52 "2005-04-20T11:43:36Z")
> [@Broomstick](#): > > There are also issues with use and maintenance of radar, which can (and sometimes have) caused injury to ground personnel when activated during maintenance. Which can add a whole new wrinkle Like [this?](http://hps.org/publicinformation/ate/q3472.html) When we have massed flying banks of x-ray guns in the sky, think of the road rage! ---
**Author:** ![vetbridge](https://avatars.discourse-cdn.com/v4/letter/v/b5e925/32.png) [@vetbridge](https://boards.straightdope.com/u/vetbridge)\ **Post date:** [April 20, 2005, 12:03pm UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/53 "2005-04-20T12:03:13Z")
I would be in line to buy a flying car, as long as Mr Spacely agreed to give me a raise. 😃 ---
**Author:** ![av8rmike](https://avatars.discourse-cdn.com/v4/letter/a/edb3f5/32.png) [@av8rmike](https://boards.straightdope.com/u/av8rmike)\ **Post date:** [April 20, 2005, 5:34pm UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/54 "2005-04-20T17:34:16Z")
> [@SCSimmons](#): > > Shouldn’t that be a ‘drug addiction _in_capacity’? Probably meant, “drug _inter_diction” Honestly, **Broomstick** , I wouldn’t waste your time doing a line-by-line dissection of the article or anything. You and I have been around here long enough to know how many times this topic has come up that you could probably just link to one of the earlier threads. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [April 21, 2005, 12:40am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/55 "2005-04-21T00:40:40Z")
> [@Hampshire](#): > > I don’t think people could afford the costs of professional maintenance and check-ups these things would need like actual aircraft do. It’s been awhile since I looked into the annual costs of maintenance, fees, etc. for the sort of airplanes I fly (as a renter I don’t pay these directly) but last I checked, assuming no _major_ problems, you’re looking at, very roughly 3,000 a year. Some years, of course, the cost will be greater but other years are lower (when you have almost no problems). Keep in mind that I fly airplanes 20-40 years old - presumably a newer machine would require fewer replacement parts and less maintenance for the same reliability. Many maintenance items can be done by the pilot/owner and don’t require a professional mechanic, such as oil changes. The new Sport Pilot category will offer the opportunity for the pilot/owner to become certified to make his/her own repairs on an aircraft. If you build an airplane under the Experimental category you can likewise make your own repairs and conduct your own inspections as well on the aircraft you’ve built. So there are opportunities for the do-it-yourself types to get properly educated on the skills needed and reduce their costs that way. Although the cost will remain higher than a car it will most likely be within the range of someone who can afford to plunk down $50,000 for a vehicle. We’re not discussing multi-million dollar jets here. > [@](#): > > If you get a flat, run out of gas, electrical problem, engine overheats, etc. in a car you steer to the side of the road and call for a jump or tow. > Something like that happens in your flying car and you can kiss your ass goodbye. Well… not really. I once had a major electrical failure in an airplane and barely noticed (I did notice the drained battery when I tried to start it again). Even if the engine quits, if you keep your head there is a high probability of making a safe landing. Things _do_ go wrong on aircraft and _usually_, after a few very tense minutes, everyone walks away intact. That’s with the aircraft we currently have - airplanes and helicopter pilots are both trained in emergency procedures including emergency landings (I even had to make use of those skills once). One of the problems, as I (and many other pilots) see it is that these are aimed at people who have NOT received such training. Another problem - arguably even more serious) - is that not all of these aircraft are _capable_ of making a power-out landing. The Moeller Skycar, for instance, is going to glide just about as well as a brick. Sure, sure, he says there’s redundancy and you’ll never have _total_ failure… well, no one ever thought a Boeing 757 would run completely out of gas mid-flight until the Gimli Glider incident. Oops. (By the way - in the Gimli incident the pilots managed to land without injury to anyone and only minor damage to the airplane despite a complete lack of engine power). It happened to an Airbus over the Atlantic a few years later, although for different reasons. (They landed safely in the Canary Islands). Now, neither of those two occurances were a good thing, but they illustrate a certain _safety_ that exists when you match well trained pilots and well designed aircraft. With some of these flying cars the intention seems to be an _un_trained non-pilot and… well, how well designed _are_ these things? What sort of backup systems do they have? ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [April 21, 2005, 12:44am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/56 "2005-04-21T00:44:58Z")
> [@Loopydude](#): > > Airbags. Big, biiiiig airbags. They are actually developing those. In airplanes and helicopters the airbag is actually mounted in the shoulder strap of the restraint harness rather than the control yoke (the thing in front of the pilot that looks like a steering wheel). Still rather new in this application, they are quite rare at this point but they are available for those who wish to install such systems. And, just because somebody is going to bring it up at some point, yes, we have parachutes for small airplanes, too. One company - Cirrus - actually installs them as standard equipment on all new planes they produce. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [April 21, 2005, 1:08am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/57 "2005-04-21T01:08:45Z")
> [@FlightlessBird](#): > > I remember in the interview this morning that the inventor said, although designed to go 300 feet up, it would be used mostly at a much lower height, thereby minimizing danger from crashes (at least from deaths) An uncontrolled crash from 20 feet up is more than enough to kill you. You wouldn’t be flying it at 20 feet anyway - too much stuff to run into. Buildings, bridges, freeway overpasses… You wouldn’t fly it at 50 feet - even if you didn’t have local skyscrapers, trees grow that high and running into them will do more than ruin the paint job. At 100 feet you’re still worrying about powerlines. Cellphone towers - which are proliferating like mushrooms on manure - are built up to 200 feet. Um… under 300 is safer? In flying, as a general rule the _higher_ you are the safer you are. For one thing, there’s a whole lot less stuff to run into. Also, if something does go wrong altitude gives you more time to fix the problem before you’re slapped by a planet. > [@](#): > > It runs on normal unleaded gas, and weighs only 250lbs qualifying it as some sort of ‘light-craft’ (I forget the actual term) which is already regulated. “Ultralight” Other regulations pertaining to ultralights (to be found under Federal Aviation Regulation Part 103) include no more than one seat, no more than five gallons of fuel, no faster than 55kts/63 mph (I may be slightly off on that), and no more than 254 lbs (minus pilot). Most do, indeed, run on unleaded _premium_ auto gas, frequently mixed with two-stroke oil for lubrication. Avoid gasahol, it does Bad Things to various bits of the engine/fuel system. Ultralights in the US actually (if you can believe this) require NO licensing and NO training to operate legally (provided you follow rules like staying away from cities). I must point out, however, that the accident/fatality rate is considerably higher among those who fly without training than among those who have enrolled in a training program (available from three different organizations) and successfully completed it. The utility of a 254 lbs flying machine is quite limited. In a legal ultralight weight is enormously important and all excess parts must be eliminated - excess parts like windshields, doors, and floors. Not many people want to sit perched on a lawnchair at 5,000 feet (I do - but then, you already knew I was strange). In many areas, such as the upper Midwest, it’s too damn cold to fly those things much of the year - not because the machine cares but because a hypothermic pilot and flying is a bad combination. The machines are lightweight and thus are tossed about by very light breezes - I never liked flying ultralights in anything over about a 10 mph wind, and 15 mph can be downright frightening. At that weight they just don’t have a lot of power - I’m only 145 lbs and on a hot summer day I could barely get off the ground. A 200 lbs man will _not_ be able to leave the runway when it’s 90 degrees and 100% humidity out in a legal ultralight. Which brings me to a point about flying in general - the weather is a much greater factor than it ever is in driving a car. As a general rule, once it’s warmed up my car will accelerate just as fast in January as in June, and go as fast regardless of the season. It’s not like that with aircraft. Air temperature and humidity can have an enormous effect. In January in Chicago a Cessna 150 carrying full fuel, me, and a passenger can climb at 800 feet per minute, maybe even more (that would probably require sub-zero temperatures). I flew one on a hot July day in the Tennessee mountains, just me and only half a tank of fuel, and barely rose at 200 feet per minute despite being significantly lighter. In winter, I can cruise in a C150 around 100 mph. In summer in the mountains it’s more like 80-90 mph _EVERY_ aircraft is affected by these sorts of factors, no matter how big or how small. Sure, a bigger engine will mitigate this to some extent - but increase the engine size and most likely you won’t have an ultralight anymore. At which I’m going to mention that there are damn few genuine legal ultralights out there anymore. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [April 21, 2005, 1:18am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/58 "2005-04-21T01:18:20Z")
> [@Loopydude](#): > > Seriously, what if this [Moller](http://www.moller.com/) guy actually produces something other than vaporcars, and he’s got a commercially-viable model for sale. It would cruise at 200-300MPH, miles overhead. It could travel hundreds of miles. It weighs over a ton. It sure doesn’t look like an ultralight to me. What is it, effectively? A plane? Yep. Under current regs a Moeller Skycar would be an _airplane_. There is no way it could qualify as either an ultralight or a sport aircraft. Why? Too heavy, too fast, and too many engines - although there are no limts on the number of engines for an ultralight (and there were a few multi-engine experiments) sport aircraft are explicitly limited to one and only one engine. And why is that? Paradoxically, the casualty rates for lightweight multi-engine aircraft are significantly higher (once you adjust for different numbers of aircraft of each type) than for single engine light aircraft. Multiple engines theoretically offer more safety, but it’s offset by a greater complexity that can and does kill people in some circumstances. In large passenger jets a combination of training and technology makes flight minus one (or sometimes more than one) engine a reasonably safe endeavor. But small aircraft pilots typically do not have as extensive training, and even when they do, many light twins can not maintain altitude on just one engine, it merely slows the inevitable descent to landing. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [April 21, 2005, 1:32am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/59 "2005-04-21T01:32:57Z")
> [@Scarface Z](#): > > Actually 10,000 feet above sea level. So you people in Colorado would be getting the short end of the stick, so to speak. That actually sounds like the Sport Pilot ceiling - so it might be a regulatory limit and not a matter of physical limits. If he’s talking about ultralights - they are allowed flight above 10,000 feet when, if I recall correctly (I never flew 'em in the Rockies so it wasn’t much of a concern to me) you are within 2,000 feet of the ground. So you could hug mountain terrain while flying over it. Mainly, the intention was to keep ultralights out of commercial flight lanes. Although at a certain point the air does thin out so much that the aircraft can no longer generate sufficient lift to gain altitude. Where, exactly, that point occurs various from aircraft to aircraft. This physical limitation kicks in sooner for rotorcraft than fixed wing, though (all other things being equal) > [@](#): > > Also: No one’s caught this yet? What kind of miracle transportation only goes 55 mph and only gives you 2 hours of flight time? I also noticed that nowhere in the article does it mention what kind of milage this flying “car” gets. And good luck pulling into a gas station. Assuming we’re still talking potential ultralights, assuming a maximum legal fuel load of 5 gallons you’re looking at a fuel burn of 2 to 2.5 gallons per hour (I don’t know if he’s considering an emergency reserve or not - he’s not required to do so in an ultralgiht) or, under ideal conditions, 22 miles per gallon. However, your fuel efficiency will decrease markedly while in a climb, and you must climb to an adequate altitude for safety. Unless you have the skill to catch and ride a thermal up into the sky (which is possible to do) if you climb to 10,000 you’re going to get really lousy mileage. And no, you can’t really pull a small aircraft - even an ultralight - into a gas station. Particulary not a gas station with an awning over it, the wings/rotors are too wide to fit underneath, or rather, between the supports. You fill gas cans (“approved fuel containers”) and haul the gas out to the aircraft. Some ultralights have fuel tanks you can easily pull off the aircraft, take directly to the pump, and fill there. Back when I was doing this, however, a lot of gas stations wouldn’t sell to you if they knew you were going to put the gas into anything like a flying machine - liability concerns, you know? So yes, fueling these things can be a pain in the butt. I should also point out the _true_ ultralight helicopters have an evil reputation among both ultralighters and homebuilders. They have killed a significant number of people. I am not a rotorcraft expert, but I gather that it is _extremely_ difficult to build an ultralight helicopter that meets the weight limits under the regulations. Ultralight _gyrocopters_ are a different matter - those do exist. ---
**Author:** ![mike1dog](https://avatars.discourse-cdn.com/v4/letter/m/ba9def/32.png) [@mike1dog](https://boards.straightdope.com/u/mike1dog)\ **Post date:** [April 21, 2005, 1:49am UTC](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091/60 "2005-04-21T01:49:22Z")
Let’s see, the prototype goes fifty miles an hour, uses four rotary engines (not noted for their fuel efficiency), and can fly for two hours. Color me underwhelmed. [Previous page](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091.md?page=2) [Next page](https://boards.straightdope.com/t/hovercars-are-here-dont-crash/300091.md?page=4)