NASA Designs All-Electric Personal Flight Vehicle

MikeChino writes "NASA is currently working on a personal aircraft that will put jet packs to shame. The Puffin is an all-electric one-man airplane that could be the start of some new and amazing air travel technology. With two prop electric engines, lithium phosphate batteries and a top speed of almost 300 mph, the vertical take off and landing vehicle was originally designed for covert military insertions because it has a lower heat signature than combustion engines. The Puffin would also be super quiet – 10 times quieter than current low-noise helicopters, and since the engine is electric it has no flight ceiling and can fly up to 9,150 meters high, uninhibited by thin air."

Comments

"No flight ceiling"

[JoshuaZ]

"since the engine is electric it has no flight ceiling and can fly up to 9,150 meters high, uninhibited by thin air." I presume they mean in this context no substantial flight ceiling where the engine gives out from lack of oxygen and you have a very bad day. That's backed up by the original article which says that "It has no flight ceiling--it is not air-breathing like gas engines are, and thus is not limited by thin air--so it could go up to about 9,150 meters before its energy runs low enough to drive it to descend." So in fact you could fly this much higher than 9,150 meters if you started out high up (from say a larger aircraft) or had a parachute. This leads to a question: How high up could it go before the air becomes too thin to generate enough lift to continue ascending?

Re:"No flight ceiling"

[gyrogeerloose]

I'm not an engineer so I can't comment on the operating ceiling of the the thing but speaking as a former private pilot, 9,150 meters (FL 28, roughly) is already well above the point where the pilot-in-command would be allowed to operate without supplemental oxygen.In fact, up that high you'd be messing with the three-holer transport jets and would probably need a pretty high-quality heated flight suit.

Re:"No flight ceiling"

[rockNme2349]

That was my personal favorite quote.

It has no flight ceiling... so it could go up to about 9,150 meters

Re:"No flight ceiling"

[ceoyoyo]

VTOL aircraft have to be overpowered to pull off the takeoff and landing, but with a top speed of 250 km/h (ground speed, presumably) and those little wings I wouldn't count on getting to 9000 metres, never mind higher.

Re:"No flight ceiling"

[Anonymous Coward]

Not only does it become difficult to generate lift, but to keep the electric motors cooled. You're always going to have losses in the form of heat and that's generally carried away by the air moving past the motor. An overheated motor when that's what's keeping you from plummeting isn't cool... literally.

Re:"No flight ceiling"

[Anonymous Coward]

Well Everest is just under 9km up, and people have scaled it without oxygen. However these were mountaineers, and not duty free guzzling pilots.

I also am completely unqualified in aerodynamics, but I would assume (most probably incorrectly) that the ceiling would be limited by the speed the rotors turn and also the length/surface area they have (assuming the pilot is appropriately dressed for the occasion).

I'm quite interested actually in any responses that could shed some light on this... seems pretty cool.

On a side note, we had here (in Australia) on "The New Inventors" some dudes that actually made a battery powered helicopter. It was kind of like a gyrocopter - pretty light weight 1 seater kind of thing. It had a pretty shitty filght time, on the order of minutes, but obviously they only used bog standard batteries (ie they didn't develop any special batteries or anything, "just" hooked them up to a motor and modified the gyro).

For those not familiar, the show basically has random people that have invented something come and show it to a panel, and they decide on a winner each week. It's pretty cool, you get anything from automatic sheep tilters(yes, that) to stuff that automatically re-sheaths pneumatic hoses. Riveting stuff :) .

Re:"No flight ceiling"

[spidkit]

The reference to max altitude being un-inhibited by thin air due to the powerplant not being combustion based is misleading. The term "service ceiling" is used to define the altitude at which (generally), aircraft will not climb at a rate faster than 100 feet per minute in a sustained climb attitude. This is a factor of air density (and max available power) - which affects both power output of the "engine" if this were a combustion engine, as well as the airfoil, and the lift (and drag) it produces (in a fixed wing craft). If the powerplant is electric, one still contends with air density which as a factor in the lift formula: L = (1/2) d v2 s CL, where * L = Lift, which must equal the airplane's weight (and pilot) in pounds * d = density of the air. This will change due to altitude. These values can be found in a I.C.A.O. Standard Atmosphere Table. * v = velocity of an aircraft expressed in feet per second * s = the wing area of an aircraft in square feet * CL = Coefficient of lift , which is determined by the type of airfoil and angle of attack. reference: http://www.grc.nasa.gov/WWW/K-12/WindTunnel/Activities/lift_formula.html If the air gets too thin - you're lift value will drop, and if it drops out (pilot plus craft weight) before the battery runs down, the craft will cease to climb because of the drop in air density.

Re:"No flight ceiling"

[garyebickford]

The other factor is that the typical propeller does become less efficient as the air gets thinner, so there is still a ceiling. Jets (turbofans) have less of an issue with this. From a quick Google, It appears that above Flight Level 240 (24000) the majority of the thrust of a turbofan comes from the jet exhaust, while at sea level most of it comes from the fan.

For me, the sheer fear factor of looking down from 9000 meters (30,000 feet) in not much more than my flight suit would be more than I'd be ready for.

But I think this could be the inspiration for the long-awaited personal aerial commuter vehicle - especially if operation can be automated, and if the redundancy mentioned in TFA can achieve no-single-point-of-failure. If routing were handled by a central traffic control system, and local traffic position were handled by an agent swarm, it could work pretty well. The VTOL capabiliy means you could land in a parking space, or on the roof. And the 80 mile cruising range would be sufficient for commuting.

Re:"No flight ceiling"

[Anonymous Coward]

Well Everest is just under 9km up, and people have scaled it without oxygen.

And I assume they went from base to peak in just a few minutes, like a "duty free guzzling pilot" would?

Re:"No flight ceiling"

[dakameleon]

From TFA:

so it could go up to about 9,150 meters before its energy runs low enough to drive it to descend

i.e. not a flight ceiling, a limitation of energy capacity.

Re:"No flight ceiling"

[Suki I]

This leads to a question: How high up could it go before the air becomes too thin to generate enough lift to continue ascending? Whatever that height is would be the flight ceiling. Still sounds like whop, whop, whopor ware to me.

Re:"No flight ceiling"

[cortesoft]

At those altitudes, wouldn't the fact that the air be EXTREMELY cold? (I think -52c or so at 30k feet?)

Re:"No flight ceiling"

[Anonymous Coward]

In the US, 17,000 ft and above is restricted airspace, you'd need permission to operate above that altitude.

Re:"No flight ceiling"

[Anonymous Coward]

My point was not the time it takes to get up there, more the fact that people can actually breathe up there, but only though training and acclimatisation. I believe it only takes a few minutes for hypoxia to set in. At those altitudes, even feeling lightly unwell can have deadly repercussions.

Re:"No flight ceiling"

[Twinbee]

Or we could have flying vehicles avoiding each other by automatically 'repelling' according to a 3D sensor (whereby closer = repel harder).

Unless you want to remove the fun out of flying.

Re:"No flight ceiling"

[karlwilson]

In aviation, a service ceiling is typically defined by the altitude that the aircraft can no longer sustain a 100 fpm climb. The only "aircraft" that don't have a service ceiling are those that go into orbit.

Re:"No flight ceiling"

[nicc777]

"For me, the sheer fear factor of looking down from 9000 meters (30,000 feet) in not much more than my flight suit would be more than I'd be ready for."

As a skydiver with HALO experience I can tell you that there is nothing to fear. You do not really have depth (or is that height) perception at that altitude. Yes, everything does look tiny and as a skydiver I sometimes wonder if I will make the target (a football field looks like a tiny dot or button below). However, since this is powered flight, that's not really an issue.

Re:"No flight ceiling"

[FlyingGuy]

Your about 10,000 feet off.

Class "A" Airspace begins at FL180 (18,000 ft AMSL) and continues up to FL600 (60,000ft AMSL). AMSL = "Above Mean Sea Level"

To fly in class "A" airspace you must be following a filed IFR Flight Plan and have two way radio communication. These are the only requirements.

There is one instance where one is required to fly VFR in class "A" airspace. Look it up! I will give you a hint: FAR part 91 and AIM 6-x-x

yes I am a pilot.

Re:"No flight ceiling"

[polar red]

Well Everest is just under 9km up, and people have scaled it without oxygen.

[citation needed]

Re:"No flight ceiling"

[Anonymous Coward]

How exactly do you get 10,000 as the difference between 17,000 and 18,000?

Re:"No flight ceiling"

[gyrogeerloose]

Well Everest is just under 9km up, and people have scaled it without oxygen.

That may very well be true but, at least in the US, the pilot-in-command of an unpressurized aircraft is required by FAA regulations to use supplemental oxygen when flying at 10,000 or feet for more than a certain amount of time.

Re:"No flight ceiling"

[khallow]

At those altitudes, wouldn't the fact that the air be EXTREMELY cold? (I think -52c or so at 30k feet?)

The problem is that air is far less dense at those altitudes. There's roughly a third the air at sea level. For example, suppose you're trying to keep the engine below 80C. An air flow at sea level and 20C that barely does it, would be equivalent to a third the airflow at -100C.

Re:"No flight ceiling"

[StarsAreAlsoFire]

about 8 seconds, at 30K feet in a decompression situation.

Or so I recall hearing. I'm sure there's plenty of better sources than me, on /. ;~)

Re:"No flight ceiling"

[gyrogeerloose]

Your about 10,000 feet off.

Yeah, I accidentally left the zero off my seat of my pants meters-to-feet-to-flight-level conversion. In fact, 9,150 meters is more like FL 300.

Re:"No flight ceiling"

[Anonymous Coward]

Flight ceiling is the altitude where a climb rate of 50ft/min can no longer be maintained.

It could, but when it gets there the battery runs out. That's similar to a range limit.

Re:"No flight ceiling"

[StarsAreAlsoFire]

Speed of sound is related to temperature ONLY. It is for this reason (ultimately) that turbo-props are most efficient for short flights, and turbofan for long flights.

Most of a ~200 mile commercial flight is spent ascending and descending. Not so much time spent at cruising altitude. Props are significantly more efficient at low altitudes, compared to turbofans. Recall that we are talking about turbine engines in both cases! The 'burn fuel in air' part of the engine is *exactly* the same. The efficiency comes down to the type of blades you're spinning - a few very long unenclosed blades work great -- right up until you have to spin the blades so fast that the Mach-effects of one blade start interfering with the air around the next blade. The fan in the turbofan uses a bunch of smaller blades designed to avoid Mach-effects of this nature. So when those effects start to come into play you see the efficiency of turbofans stay the same (basically) while the efficiency (and eventually capability, if you keep climbing) of the turboprop plummets.

Of course there's all sorts of craziness regarding gear ratios and a bazillion other things that I completely ignored here. But as a high level overview, it's not worthless.

If you can do VTOL, you design for sea level -- a huge portion of your fuel/energy tends to go into getting you up and down. So how high can you CRUISE on a prop designed for optimal performance at sea level? At a guess, closer to 5km/12k feet than to 10km/33K feet, driven by the weight-cost of pressurizing the beast. But there are a bunch of variables:

- What speed do you want to cruise at?
- What is your range? Is it WORTH getting to 30k (40k, 50k, 12k) feet, only to start descending as soon as you do?
- How much can you feather your prop blades? (Change their pitch, letting you spin the blade faster at high altitudes while decreasing blade turbulence)
- What is your L/D? (Lift to drag ratio) At sea-level, your optimal speed may be 200mph. At 30K feet you have to go 300mph for the same amount of lift. Lift to drag ratio tells you that the amount of energy required to overcome that induced drag is the same for 200 mph and sea level as it is for 300mph and 30K feet.
(But that doesn't take prop drag into account. If your prop flies apart because you have to turn it at 20K rpm to stay in the air at 30K feet, all bets are off.)
- more and more, and weather, and a lot about temperature, and how much does it cost to pressurize the cabin, etc).

As for ultimate limits, the difference between stalling and breaking the sound barrier was about 50 knots for the U2 flights. That may have been plus or minus 50', but I think it was actually +/-25. Memory fails. Anyway, 68K feet is a *seriously* nerve-wracking place to fly if your airplane can't do Mach.

The F-15 managed a zoom-climb 'somewhere in the region of' 70K (I've seen 80k cited) feet. That is 'go as fast as you can at the highest altitude that your engines stay lit, and then dive, to go even faster. Then, at a very exact point determined by guys with slide rules, kick on the after-burners and start climbing at a particular angle. Then your engines burn out, then you coast. If you are in the united states and flying an F15, you launch a missile that destroys a satellite. Then plummet back to earth completely out of control, because there is no air going across your control surfaces. And hope you don't enter at the wrong angle, because there are ways you can come back to earth which would preclude you re-lighting your engines in time to save the plane. Nobody WANTS to eject.'

Re:"No flight ceiling"

[timeOday]

But the aircraft weighs about the same anywhere in this altitude range. To maintain altitude, you must apply enough force to the air to equal the pull of gravity on your aircraft. So the product of airmass and downward airspeed remains constant (f=ma). So if the downward airmass is less, the downward airspeed must be greater, which would increases heat transfer to some degree. Greater downward airspeed would also increase the volume and thus the total downward airmass, so the difference in downward airmass must be less than the difference in air density.

Hmmph, let's just start flying up and see what happens to the temperature gauge!

Re:"No flight ceiling"

[Anachragnome]

Ask the fucking craziest of them all, http://en.wikipedia.org/wiki/Joseph_Kittinger .

Personal experience is as good as it gets...

"Capt. Joe W. Kittinger achieved the highest and longest (14 min) parachute jump in history on August 16, 1960 as part of a United States Air Force program testing high-altitude escape systems. Wearing a pressure suit, Capt. Kittinger ascended for an hour and a half in an open gondola attached to a balloon to an altitude of 102,800 feet (31,330 m), where he then jumped. The fall lasted 4 minutes and 36 seconds, during which Capt. Kittinger reached speeds of 1142 km/h (714 mph) [9]. The air in the upper atmosphere is less dense and thus leads to lower air-resistance and a much higher terminal velocity."

Gives the phrase "No Fear" a whole new meaning.

Re:"No flight ceiling"

[wagnerrp]

From a quick Google, It appears that above Flight Level 240 (24000) the majority of the thrust of a turbofan comes from the jet exhaust, while at sea level most of it comes from the fan.

While possibly true in practice, it has nothing to do with altitude. Thrust comes from the mass flow rate, times the change in velocity. Aside from fighter jets on afterburner, the exhaust coming out of a jet engine will be subsonic. The speed of sound is proportional to the square root of temperature, so the hot core flow will be much faster than the relatively cool bypass flow.

So what relevance is this to anything? By 'sea level' the quote you saw probably meant 'take off', or zero forward velocity. FL240 would be cruise at 500-550 knots. You have high mass flow but low velocity through the bypass fan, and high velocity but low mass flow through the core. At cruise speed, the velocity differential of the bypass flow may only be 1/4 what it was static, while the much hotter and faster core flow still has more than half its differential. Modern high bypass turbofans have ratios of 9:1 or better, so the bypass will still be producing more thrust than the core even at the reduced efficiency.

Re:"No flight ceiling"

[Avtuunaaja]

http://en.wikipedia.org/wiki/Mount_everest#Using_bottled_oxygen

Didn't bother to use half a minute to check wikipedia?

Re:"No flight ceiling"

[wagnerrp]

As for ultimate limits, the difference between stalling and breaking the sound barrier was about 50 knots for the U2 flights. That may have been plus or minus 50', but I think it was actually +/-25. Memory fails. Anyway, 68K feet is a *seriously* nerve-wracking place to fly if your airplane can't do Mach.

It was +/- 5 knots. Luckily at that altitude, there are no gusts.

Re:"No flight ceiling"

[Khyber]

Typical /. bullshit.

Those that have scaled Everest are the people that set the standard.

If this story can't compensate for that, fuck citations - go back to school.

Re:"No flight ceiling"

[Anonymous Coward]

You do get a problem where the partial pressure of oxygen in the blood is insufficient for it to release from haemoglobin, and even pure O2 won't help you. That happens pretty close to Everest height.

Re:"No flight ceiling"

[ravenspear]

Well Everest is just under 9km up, and people have scaled it without oxygen. However these were mountaineers, and not duty free guzzling pilots.

Also that's a totally different scenario. High altitudes like that without oxygen while mountain climbing are achievable only by letting the body acclimatize for several weeks at progressively higher altitudes during the climb.

You take anyone at sea level and put them immediately at 9km up without oxygen, they will pass out within minutes.

Re:"No flight ceiling"

[Anonymous Coward]

Remember not to go too close to the sun, your wings just might melt.

Re:"No flight ceiling"

[rts008]

For those not familiar, the show basically has random people that have invented something come and show it to a panel, and they decide on a winner each week. It's pretty cool, you get anything from automatic sheep tilters(yes, that) to stuff that automatically re-sheaths pneumatic hoses. Riveting stuff :) .

Thanks for the tip...looks like an interesting show, and unlike hulu, it's available to out of country viewers!!

Going for broke:
Sheep tilter:Featherbee Shearer's Trolley
Helicopter:Co-axial Rotor Helicopter

Did I get the correct videos you referenced in your comment?

Re:"No flight ceiling"

[Fred_A]

Well Everest is just under 9km up, and people have scaled it without oxygen.

And I assume they went from base to peak in just a few minutes, like a "duty free guzzling pilot" would?

They'd better get up in less than 3.5 minutes or else the batteries will be flat and you wouldn't want that to happen at that altitude, especially when you've just passed out from lack of oxygen.

Re:"No flight ceiling"

[aug24]

For me, the sheer fear factor of looking down from 9000 meters (30,000 feet) in not much more than my flight suit would be more than I'd be ready for.

Yeah. To correct the GP:

In fact, up that high you'd be messing with the three-holer transport jets and would probably need a pretty high-quality heated flight suit with a built in diaper.

Justin.

Re:"No flight ceiling"

[rts008]

polar red [citation needed]

You have not heard of google, or wikipedia? Where have you been for the past few years, you lazy, incompetent fscker?

By your /. UID, I suspect you have been frequenting digg or 4chan for the past few years instead of /....get with the program, you lazy fsck!

Re:"No flight ceiling"

[master5o1]

Well Everest is just under 9km up...

Yeah, but this thing can apparently go over 9000 metres high! Comparison to anything under 9k up is nonsensical.

Re:"No flight ceiling"

[Anonymous Coward]

The funny thing about height is that there seems to be a peak of scariness somewhere around 300 meters / 1000 feet. At that altitude you are still low enough to see people on the ground.

Once you get up to the level where they usually turn off the seatbelt sign, you are so high up that it becomes instinctively unfathomable how high up you are. It looks more like a video game map than real life.

The captain may give some mini sightseeing tips when you are cruising at FL320, like: "...and now to our left is Mt. $FamousMountain."

No it's not. That's a brown-grey-green blob of paint with traces of white mixed in.

Re:"No flight ceiling"

[Alioth]

Actually, there is little or no fear factor when you're that high up - the ground looks so far away as to be pretty unthreatening. There's a lot more fear response from being close to the ground, but just high enough to kill you - say 30 or 40 feet.

Re:"No flight ceiling"

[L4t3r4lu5]

yes I am a pilot.

Rubbish! I refuse to believe you know anything about this topic until you have a /. ID which reflects your expertise in thi.... Oh.

Re:"No flight ceiling"

[TheRaven64]

One of the people I learned to fly with was afraid of heights. She couldn't look down from a cliff or a tall building, but had no problem flying because there is no real sense of scale after the first couple of seconds from takeoff until just before the landing, and on the landing your attention is so focussed on the approach that you don't notice the height.

Re:"No flight ceiling"

[TheRaven64]

The point from TFA is not that it doesn't have a flight ceiling, but that it runs out of 'fuel' before it reaches one. If it had some in-air recharging mechanism then it would be able to climb above this ceiling. It's a shame the range is so low (80km), but maybe it will improve over the next few years.

Re:"No flight ceiling"

[Uzik2]

I don't get fear of heights at 30000ft... At 30ft it's another story.

Re:"No flight ceiling"

[garyebickford]

Hmm. Interesting point. Also, to some extent I think it is a matter of choice. I never had issues with height when I was a kid - climbed 200 ft. fir trees like a monkey, used to hang out in the top and read books. More recently I've had issues. But then I bought a sailboat. It took me a while to get myself to start climbing the mast but once I got up there (65+feet above ground at the time) and started appreciating the view, the fear went away. I still respect the height but I don't seem to have the fear like I used to. So in part maybe it's a mental habit.

Re:"No flight ceiling"

[home-electro.com]

Hm... Vertical Take off on a electric motor... Minimum 400 kg lift force? I'm too lazy to convert it to required motor power but it sounds not feasible.

Re:"No flight ceiling"

[mpe]

The other factor is that the typical propeller does become less efficient as the air gets thinner, so there is still a ceiling. Jets (turbofans) have less of an issue with this.

The most obvious difference is that the blades of the fan on a turbofan cannot change their pitch, whereas this is possible with a prop.From a quick Google, It appears that above Flight Level 240 (24000) the majority of the thrust of a turbofan comes from the jet exhaust, while at sea level most of it comes from the fan.

At sea level you need more thrust to maintain speed, since the denser the air the higher the drag. The added complications are that the density of air also affects lift, such that the higher you are the faster you need to fly to generate sufficent lift. Fly too high and you will encounter what pilots call "coffin corner", since you'd need to fly faster than Vne in order to generate enough lift.
The other issue is that internal combustion engines can become limited by the amount of available oxygen. Whereas an electric motor can deliver the same amount of power at any altitude. Typically this is not an issue since a planes engines will provide sufficent thrust for it's cruise altitude. Only if an engine fails the remaining engine(s) remaining engines are unlikely to be able to provide sufficent thrust, since jet engines typically have a "relight ceiling" and the rules for a twin are "land at nearest suitable airport in the case of an engine failure" it's likely to be necessary to descend anyway.

Re:"No flight ceiling"

[mpe]

Also that's a totally different scenario. High altitudes like that without oxygen while mountain climbing are achievable only by letting the body acclimatize for several weeks at progressively higher altitudes during the climb.
You take anyone at sea level and put them immediately at 9km up without oxygen, they will pass out within minutes.

Much the same is likely to happen even starting at about 2.5km. (The typically "cabin altitude" of an airliner.)

Re:"No flight ceiling"

[khallow]

So if the downward airmass is less, the downward airspeed must be greater, which would increases heat transfer to some degree.

It'd also increase heating of your electric motors.

Re:"No flight ceiling"

[Anonymous Coward]

No, your point was to trash-talk drunken fly-boys for being wusses because they're required by law to have supplemental oxygen while "real men" mountaineers scale Everest with none.

My point was to say that you're comparing apples to pancakes.

Re:"No flight ceiling"

[tom17]

So the fast show wasn't that far off then it seems :)

That's Amazing

Tom...

Re:"No flight ceiling"

[robinstar1574]

Well Everest is just under 9km up, and people have scaled it without oxygen. However these were mountaineers, and not duty free guzzling pilots.

However, mountaineers need much more oxygen then piolets need to do the tasks they are conducting.

Re:"No flight ceiling"

[robinstar1574]

well some idiot fell from 10 km without a parachute and is in the Guiness Book of Idiots (do they get sent a bottle of finest guiness if they get in?)

Re:"No flight ceiling"

[berashith]

I hope control could be automated. It would be nearly impossible to pay attention to the other flyers while texting.

Re:"No flight ceiling"

[fifedrum]

Capt. Kittinger (still flys balloons!) wore a space suit, and has big brass bowling ball sized testicles that put the rest of us to shame.

Re:"No flight ceiling"

[Josh04]

It's a joke about them doing it with no oxygen, those of you with no humour gland.

Re:"No flight ceiling"

[idontgno]

I bet a joke going over your audience's heads makes an odd-sounding whoosh at 9km msl. Thin air and all.

Re:"No flight ceiling"

[FlyingGuy]

Doh!

Re:"No flight ceiling"

[FlyingGuy]

heheeheh Pants-O-Meter. I like it!

Re:"No flight ceiling"

[GooberToo]

Well Everest is just under 9km up

Most non-athletic, non-smokers start to get oxygen deprived at around 10,000 feet. For smokers, this can start as low as 6,000 - 8,000 feet; depending on health and consumption. The FAA officially recommends O2 if flying at or above 10,000 for longer than 30 minutes. The reason being, most people's higher faculties start to become compromised; and more so the longer they remain at such altitudes.

Furthermore, the FAA requires O2 when flying at 12,500 - 14,000 for longer than thirty minutes. All flights above 14,000 require O2 at all times.

To bring this full circle, the kicker is, many in the medical community believe oxygen deprived brains on Everest has directly caused the death of many climbers as their higher brain functions, which would otherwise tell them to retreat, has been compromised. Rather than retreat to safety, compromised brains continue forward and upward, resulting in the death of the climber.

Re:"No flight ceiling"

[nanospook]

Probably 9150 meters is the ceiling.. don't say they didn't tell you so!

Re:"No flight ceiling"

[phtpht]

Fear of heights is influenced by your cognitive process. As a kid you did not fully realize the consequences of falling down, but as your age progressed, you have learnt of them. The kid's mind is generally much more free due to lack of negative experience.

Re:"No flight ceiling"

[MrHops]

I'm not an engineer so I can't comment on the operating ceiling of the the thing but speaking as a former private pilot, 9,150 meters (FL 28, roughly) is already well above the point where the pilot-in-command would be allowed to operate without supplemental oxygen.In fact, up that high you'd be messing with the three-holer transport jets and would probably need a pretty high-quality heated flight suit.

Erm, FL 280, right?

Re:"No flight ceiling"

[gyrogeerloose]

Erm, FL 280, right?

Right. Forgot the zero, but it's actually closer to FL 300. See below.

Re:"No flight ceiling"

[Anonymous Coward]

I watched a program about him..It showed the film he captured on the way down.AMAZING.I seem to remember that it was totally quiet when he stepped off and his suit wasn't getting whipped about by the wind for the first minute...Has anybody ever repeated his jump yet?

CG concept only

[QuantumG]

By March, the researchers plan on finishing a one third-size, hover-capable Puffin demonstrator, and in the three months following that they will begin investigating how well it transitions from cruise to hover flight. They are already looking past the Puffin, however.

And that's why we'll never see a full sized vehicle.

The next-generation of this design might incorporate more than just two pairs of prop rotors, so that if one was struck by, say, a bird or gunfire, the aircraft could survive on redundant systems. "We could make it so there's no single point of failure--that's the cool next step," Moore says.

Ya know what a cool next step would be? Actually making the vehicle.

Re:CG concept only

[Ethanol-fueled]

And that's why we'll never see a full sized vehicle.

Wrong. In fact, it reeks of the spectacular(yet somehow still operational) failure known as the V-22 Osprey.
Here's an obligatory video which showcases the V-22's stability ~ .

Note that the video in TFA is a cutesy CGI video and not actual footage of the flight of a prototype. In actuality, the vehicle won't be as efficient as a suicide booth, but it'll will be much more fun.

Re:CG concept only

[scdeimos]

Your V-22 video was an unfortunate example. The V-22/XV-15/BA-609 tilt rotor platform is generally stable and easily controlled, ala this video.

Re:CG concept only

[ZosX]

4 crashes since its inception? That really isn't so bad. You should compare with other military planes. Also at least half of those crashes were due to maintenance, parts failure issues and really have nothing to do with the actual design of the craft. I would say the press did a pretty good job of convincing everyone that the V-22 was a flying deathtrap.....

Re:CG concept only

[jcr]

4 crashes since its inception? That really isn't so bad. You should compare with other military planes.

Hell, just compare it to the early helicopters. The tilt-rotor concept is a major advancement. The accidents are regrettable, but not at all surprising.

-jcr

Re:CG concept only

[Required Snark]

Why is there a requirement that NASA build a full scale version? Because you said so? They are building and flying a 1/3 scale version to test the design. It will be used to test the transition between vertical take off, horizontal flight, and vertical landing. If they were to go further with this design it is a reasonable step to take. So how is this not real?

You want a full scale version, how about you fund it yourself. NASA has procedures for working with outside organizations. You could do it out of your vast personal fortune, or raise the venture funding.

The last I heard NASA did research, not making production prototypes. I would say this is in their charter. Why are you bitching?

Re:CG concept only

[Anonymous Coward]

the reason you'll *never* see personal transport aircraft is why they've been nothing but a pipe dream anyway...if you can't have trouble free traffic on the ground, would you want the idiot next door flying over your house during rush hour???

Re:CG concept only

[zippthorne]

The people that tend to get all vitriolic about the Osprey are generally the people who don't like any spending on military hardware ever. There tend to be a lot of tin-foil hats (where to they even find it. All I can find is lousy aluminum foil..) and eisenhower quotes. Actually, just one eisenhower quote, but repeated, a lot.

Re:CG concept only

[timeOday]

By that logic rocketry is also infeasible. (Gotta love the choice of soundtrack on that video!)

That Osprey crash is pretty horrendous, but it was also 20 years ago.

Re:CG concept only

[timeOday]

The people that tend to get all vitriolic about the Osprey are generally the people who don't like any spending on military hardware ever.

To be fair, it has a body count of 30 people in 3 separate incidents, even before it reached operational status. Very few defense programs must own up to that kind of numbers.

That said, I now see them flying around most days of the week and they are sure cool!

Re:CG concept only

[vtcodger]

***the reason you'll *never* see personal transport aircraft is why they've been nothing but a pipe dream anyway...if you can't have trouble free traffic on the ground, would you want the idiot next door flying over your house during rush hour???***

That's one reason. Insurance costs for personal aircraft are likely to be prohibitive.

Other reasons:

    Maintenance: Broken cars stop. Broken aircraft drop. Personal air vehicles are surely going to need much more, and much better, maintenance, than cars.

    Control: Keeping a car under control and pointed where it belongs is near the limits of many people's abilities. Are they going to be able to handle navigation in three dimensions?

    Security: Car bombs are an ongoing problem in the Middle East. How are you going to secure any facility if the air is full of potential DIY cruise missiles?

Re:CG concept only

[jcr]

I'm no fan of military spending myself, but the osprey was considerably cheaper than the F22, which is exactly what we need to fight the Soviets! Oh, wait.

Anyhow, I'd like to see the tilt-rotor concept applied to civilian uses. Speeding up city-center to city-center trips would be pretty handy.

-jcr

Re:CG concept only

[teh kurisu]

Broken cars stop. Broken aircraft drop.

The maintenance problem is lessened in comparison to normal cars by the use of an all-electric drivetrain, where there is much less that can go wrong. Really the problem I'd be more worried about is running out of electricity. People still run out of petrol on the roads, and have to call the AA (or equivalent) to get them moving again. How many people will try to push it that extra couple of miles only to discover that they don't have enough energy left for a controlled landing?

Autogyros don't suffer from the falling out of the sky problem; they're able to descend safely in the event of engine failure.

Re:CG concept only

[Chelloveck]

Yeah, at this point it seems to be just another one of the "Flying cars! Personal jet packs! Real Soon Now!" announcements we've been seeing for the past 50 or 60 years. Let me know when they're in production. I'm not going to hold my breath.

thin air?

[SuperBanana]

since the engine is electric it has no flight ceiling and can fly up to 9,150 meters high, uninhibited by thin air

Seriously, who who wrote this? Thin air = less air for the props to bite, and less air to provide lift for the wings.

And who calls an electric motor an "engine"? Gaaaah. If this were Wired, I'd be more forgiving on both counts- but this is Scientific American!

Re:thin air?

[AJWM]

Seriously, who who wrote this? Thin air = less air for the props to bite, and less air to provide lift for the wings.

While you're right about this, of course, the problem is compounded with combustion engines because with altitude the thinner air means less oxygen to burn fuel with. Just when you need more power to turn the prop faster (or at higher pitch)*, you have less power because of relative oxygen starvation. Electrics avoid that problem, but yes ultimately you reach an altitude where you can't get any more lift at the airspeed you can reach with maximum power to the props.

(*And of course that's not straightforward either because it's easier to turn a prop in thinner air -- just not as effective. Flight controls include a mixture setting so that the engine doesn't run over-rich at altitude, and even some single-engine planes have constant-speed props whose pitch is variable.)

Re:thin air?

[MichaelSmith]

I thought NASA had solved our orbital launch problems for ever.

Re:thin air?

[Thagg]

Note well that the highest flying prop plane ever, the Aerovironment Helios, flew to 96,000 ft -- far higher than almost any other plane (probably the only one that could sustain that altitude was the SR-71). The Helios was powered completely by solar cells and electric motors.

Re:thin air?

[Dr_Terminus]

Considering the Grob Egrett (http://en.wikipedia.org/wiki/Grob/E-Systems/AlliedSignal_Egrett) has a ceiling of 13 km and is driven by a turboprop, I dont see any reason why the Puffin shouldnt be able to go to 9km.

psst, NASA, just one little thing.

[140Mandak262Jamuna]

Those little bars on the display that shows the charge remaining? Don't trust it. It does not work.

Re:psst, NASA, just one little thing.

[Anonymous Coward]

that's why you grab batmon.deb

Re:psst, NASA, just one little thing.

[Anonymous Coward]

It would if the charge logic had additional data lines to communicate if some of the lithium cells had been disabled.

This is the current problem with consumer electronics, is that the charge logic does not convey to the device that it has disabled some of the cells for safety reasons, and that thus, your 5000mAh battery is really only a 3200mAh battery. Thus, the device presumes it has more power remaining than it actually has.

If the charge logic properly reported what kind of cell it was attached to, how many cells were functional, and what the charge states were of those cells, it would result in a more or less accurate (to within a minute or so) of the actual charge time remaining.

The problem is that charge logic of that kind would increase the weight of the battery, increase the complexity of the battery, and increase the cost of the battery. All three things are subjects that consumer electronics bean counters dont want to even consider doing unless absolutely necessary.

Considering that this is being engineered for military purposes, I'd expect much better charge logic to be installed, and for the battery meter to be more accurate than the one for your 3oz cellphone.

My question is..

[cyberzephyr]

How long will this stay in the air?

Jet packs last about 90 seconds? Hmmm

Re:My question is..

[R3d M3rcury]

Well, let's see...

FTFA:

[...] the Puffin can cruise at 240 kilometers per hour [...] With current state-of-the-art batteries, it has a range of just 80 kilometers if cruising [...]

So it can stay up about 20 minutes.

It would work for me. I could get to work in about 15 minutes and plug it in. At the end of the day, it's all charged up and I take it home.

So, yes. I want one.

Re:My question is..

[ZosX]

Seeing as how they are now making R/C planes with electric motors (the jet models come to mind) I think this could have some sort of reasonable range. Even a couple of hundred miles would be plenty. Remember that airplanes can be more efficient than cars because there is actually much less resistance.

Re:My question is..

[Idiomatick]

Work.... :/ I think if I had a personal flying machine like this I think it'd be my personal duty to watch over the city and fight crime from the skies.

Re:My question is..

[rockNme2349]

Becoming airborne is not a requisite of a body with a lower coefficient of drag.

Design a car with a body of an airplane and you will get great fuel efficiency, the only problem is convincing people to drive it.

Re:My question is..

[Sulphur]

If I were flying this, I could jump 3m up.

Re:My question is..

[nicc777]

Will work for me too! Where do we place orders?

Re:My question is..

[jamesh]

"Puffin Man" doesn't have quite the same ring to it though, compared to the names of other super hero's...

Re:My question is..

[TapeCutter]

"Design a car with a body of an airplane and you will get great fuel efficiency, the only problem is convincing people to drive it"

....and finding a very long car park.

Re:My question is..

[wagnerrp]

Design a car with a body of an airplane and you will get great fuel efficiency, the only problem is convincing people to drive it.

See... http://en.wikipedia.org/wiki/Aptera_2_Series

Re:My question is..

[Calinous]

Cruise uses less power than ascending (take off) - so you'd need to reduce your estimate. As for the 15 minutes, I wouldn't much trust batteries to not lose performance over time (looking at my mobile phones).

Re:My question is..

[rts008]

Puffin Man, what does your costume look like?
I think your crime fighting would devolve into gathering up those criminals that would collapse into laughter at your costume.

Re:My question is..

[mcgrew]

I'm walking distance to work, so it would do no good for me there; If it rains or is cold I drive, and I would even if I had one of those. I'll want one if it get to about 120 miles, though, as I frequently travel to St Louis, 100 miles away. I could get there in 20-30 minutes as opposed to the hour and a half the drive takes.

Yet, if it were cold or raining I'd still drive there.

Go the "Green Spin"

[scdeimos]

Moore and his colleagues ... named their craft the Puffin because "if you've ever seen a puffin on the ground, it looks very awkward, with wings too small to fly, and that's exactly what our vehicle looks like," he explains. "But it's also apparently called the most environmentally friendly bird, because it hides its poop, and we're environmentally friendly because we have essentially no emissions.

Yeah, environmentally friendly except for that nasty lithium stuff in the lithium phosphate batteries.

I can't help but wonder what the glide slope on this thing is like - with those small wings, how quickly will it hit the ground if it runs out of power.

Re:Go the "Green Spin"

[jcr]

how quickly will it hit the ground if it runs out of power.

You should be able to auto-rotate like you can with a helicopter. Also, there's always the parachute option.

Re:Go the "Green Spin"

[im_thatoneguy]

Could always install one of those light aircraft parachutes they've got now a days. Trick would be finding a place to set it down in an urban setting.

Re:Go the "Green Spin"

[John Hasler]

> ...that nasty lithium stuff...

There is nothing particularly nasty about lithium.

Re:Go the "Green Spin"

[Idiomatick]

Lithium batteries are recyclable.... Also I imagine it'll force you to land before it runs out, unless you mean the batteries falling out of the vehicle or something.... Then yeah that'd be a problem.

Re:Go the "Green Spin"

[Ihmhi]

Oh great, so not only would you break both of your legs but you would have a wicked case of motion sickness to boot.

*spinspinspin* *thud* *crack* *BLEEEEEEEEEEGH* *whimper*

Re:Go the "Green Spin"

[TapeCutter]

Pot meets kettle, environmentally_friendly != environmentally_perfect.

Re:Go the "Green Spin"

[kievit]

Another "green" issue is that while a puffin may consume less power than a propellor plane powered by a combustion engine, flight is still less energy-efficient than transport by wheels (train, car, bike). As far as I know currently only a tiny fraction of electric power worldwide is generated with environmentally friendly techniques. So I'd like to see the kWh scores compared between a puffin and an electric car.

when i can buy one at walmart

[timmarhy]

that's the acid test. until then, i refuse to believe it exists.

Re:when i can buy one at walmart

[Anonymous Coward]

that's the acid test. until then, i refuse to believe it exists.

If WalMart starts selling them, that's it. I will never. fly. again. Have you seen the people who shop at Walmart?

And don't get me started on the people who own and run it.

Re:when i can buy one at walmart

[Anonymous Coward]

Then cars and planes don't exist. I don't see them at Walmart either :/

Re:when i can buy one at walmart

[tibman]

What? Likes cars, porn, and a decent video card?

Cool toy, but we can't have it.

[zeugma-amp]

The U.S. government will never allow widespread use of such a craft. The FAA is trying to essentially eliminate community airfields with their regulations and "anti-terrorist" programs. While I'd love to be able to fly to work, it's just not.going.to.happen.

Re:Cool toy, but we can't have it.

[mcgrew]

The FAA is trying to essentially eliminate community airfields with their regulations and "anti-terrorist" programs. While I'd love to be able to fly to work, it's just not.going.to.happen.

Never say never. Things change, sometimes quickly. I never thought I'd see the US using torture, or denying Habeus Corpus, or imprisoning people without trial, but it happened. And the pendulum always swings back.

In 57 years you see a lot of shit happen.

Re:Cool toy, but we can't have it.

[Beezlebub33]

This seems to be offset by the new category of light sport aircraft and the sport pilot certification. How are they simultaneously trying to expand flying and reduce flying?

Meh...

[Anonymous Coward]

The Mythbusters already built one. Nothing to see here, move along.

Been there, done that

[arcsimm]

Somewhere in Switzerland, Yves Rossy is wondering what took NASA so long.

Is Elmer Gantry Available?

[b4upoo]

I will believe it when I see it. Batteries that good are a dream. And as far as the nearly 30,000 foot ceiling of this device cold and thin air might be a serious issue. Pilots generally like to breath and being turned into a frozen, air starved corpse is not a goal for most of us. Or are we supposed to think this thing with have a closed cabin with oxygen and heat available? Jesus, we can't even get good batteries for electric bicycles yet.

Re: Is Elmer Gantry Available?

[Tablizer]

being turned into a frozen, air starved corpse is not a goal for most of us.

Exceptions for lawyers, politicians, and SCO employees.
   

Re: Is Elmer Gantry Available?

[Sir_Lewk]

Three words: Heated pressure suits.

Re: Is Elmer Gantry Available?

[FooAtWFU]

Pilots? Pffffft. Think of the drones!

Re: Is Elmer Gantry Available?

[Idiomatick]

Don't fly it that high? ... I know everyone on /. thinks they are ironman or something but seriously it probably isn't a good idea.

Re: Is Elmer Gantry Available?

[jcr]

Don't fly it that high?

Oh, you're no fun.

Seriously though, you're right. If I had one of these gadgets, I'd probably fly it around 500 to 1000 feet high most of the time, unless I was required to be higher for noise abatement.

-jcr

Re: Is Elmer Gantry Available?

[Anonymous Coward]

Listen: this isn't for you. You still aren't going to get a flying car.

This is for the military. Add an autonav like a Reaper, and you can have forward-deployed troops resupplied with ammo/food/gear and (possibly) take back the wounded without having to clear an airfield/call SAR/etc. There will be an entire MOS of the Air Force or Army dedicated to swapping out batteries and running these things.

And part of the project is named Icarus?

[JoshuaZ]

I don't understand why so many flight related programs are named Icarus. Let's remember what happened in the myth of Icarus: He flew too close to the sun and so he died. I can't tell if such program names are deliberately humorous (hah! Let's see if we can get pilots to fly in something named Icarus! Yeah, I already did that. Let's try to see if we can get them to test out a project named after a flightless bird. Maybe something like a kakapo http://en.wikipedia.org/wiki/Kakapo that sometimes gets hurt from thinking it can fly when it can't), or if they just don't know any other myths related to flight, or if this is a deliberate comment about how many classical claims about "hubris" simply hold humans back from genuine progress. But would it hurt if occasionally a program was named after Horus or after Odin's raven?

Re:And part of the project is named Icarus?

[jcr]

I don't understand why so many flight related programs are named Icarus.

It's because most people don't know who you're talking about if you say Daedalus.

-jcr

Re:And part of the project is named Icarus?

[jamesh]

Let's try to see if we can get them to test out a project named after a flightless bird.

There is an ISP in Australia called 'Dodo', and their most commonly used marketing statement is 'Internet that flies'. I thought that was kind of clever given that the Dodo is flightless, and extinct.

Re:And part of the project is named Icarus?

[evilviper]

I can't tell if such program names are deliberately humorous

No, YOU are simply focusing on the wrong part of the story...

But would it hurt if occasionally a program was named after Horus or after Odin's raven?

How many people would recognize the reference? Far fewer, I'd say.

Re:And part of the project is named Icarus?

[Anonymous Coward]

Here's one of their justifications for the name Puffin:

"But [the puffin is] also apparently called the most environmentally friendly bird, because it hides its poop"

An inspired choice.

Re:And part of the project is named Icarus?

[Anonymous Coward]

The CG concept should be called Daedalus, the actual physical construction Icarus, and the final mass-produced vehicle, Helios!

Re:And part of the project is named Icarus?

[Mark_in_Brazil]

I don't understand why so many flight related programs are named Icarus. Let's remember what happened in the myth of Icarus: He flew too close to the sun and so he died.

Yeah. Imagine what I thought when I got on a Varig plane for an international flight back in the '90s and saw that Varig's in-flight magazine was called &Iacute caro.

Re:And part of the project is named Icarus?

[mcgrew]

But would it hurt if occasionally a program was named after Horus or after Odin's raven?

My eye doctor doesn't have a raven!

I understand all this

[SuperBanana]

While you're right about this, of course, the problem is compounded with combustion engines because with altitude the thinner air means less oxygen to burn fuel with

No kidding; I don't deny this. But the article doesn't say that it has a higher ceiling; it says: "It has no flight ceiling."

That is utter bullshit!

Re:I understand all this

[Idiomatick]

It only sorta says that... I mean it does but it says what the flight ceiling is in the same line, obviously they meant they don't succumb to oxygen starvation like regular choppers/planes. Which they say later in the paragraph....

I don't think this was a scientific error or reporting error but rather an English error.

Re:I understand all this

[Anonymous Coward]

It says that because it it runs out of fuel before it reaches it's flight ceiling, so it makes no sense to speculate what it would be if that didn't happen.

Not a good sign

[Anonymous Coward]

The dude in the simulation has no nuts. Flight accident? Count me out.
 

Uncle

[The Yuckinator]

Seriously, it would be a hell of a lot of fun, and probably a challenge to learn to fly as competently as a good driver drives a car.

But the day they open a dealership in Toronto is the day I stop driving. Not that pedestrians are all that safe in this city these days, but I'm already concerned enough with a significant portion of the other people on the road. No way I'm going to share airspace with them too!

Re:Uncle

[im_thatoneguy]

Why have a pilot? I doubt the thing will stay airborne without a computer anyway. I can't believe that a pilot would be as capable as an autopilot computer in this instance.

Re:Uncle

[WillDraven]

Yeah, maybe the only control these things should have is a big red "OHSHIT" handle that deploys a big parachute and airbags.

Still only 20 minutes

[rockNme2349]

n principle, the Puffin can cruise at 240 kilometers per hour and dash at more than 480 kph.

With current state-of-the-art batteries, it has a range of just 80 kilometers if cruising,

That's a flight time of (80km/(480km/hr)) = 20 minutes. Less than impressive even if they actually were to produce it.

Although that is a problem they seem to have solved by making it with batteries which don't exist yet.

Re:Still only 20 minutes

[Deosyne]

Far enough to get me to work, although I'd have to recharge here before heading home.

Safe design?

[Anonymous Coward]

Great! it's your head first hurt once you hit the ground in case of accident. I suppose this is to save you some pain in case you survive otherwise.

Earth to Orbit vehicle?

[DJRumpy]

This is odd that someone hasn't already cashed in on this. Is this a possible precursor to a simple earth to orbit vehicle? From what I read in TFA, the limit quoted is simply due to the capacity of the batteries, however this uses a simple rotary blade system similar to a helicopter for lift. It would definitely fail when the atmosphere thinned out.

Can someone familiar with this type of design give an idea of exactly how high this could be expected to fly if the batteries were not the limiting factor?

Re:Earth to Orbit vehicle?

[Brett Buck]

This is odd that someone hasn't already cashed in on this. Is this a possible precursor to a simple earth to orbit vehicle?

    Not in any way, shape, or form. Getting to 20-30000 feet, if it was capable of that, with a very small payload, it essentially worthless in terms of orbital. To get into orbit the chief challenge is velocity. To get that (without other far more interesting technical breakthroughs) you need a HUGE rocket with very large amounts of fuel. So there is really no role at all for this teeny little helicoper/VTOL airplane.

          Brett

Re:Earth to Orbit vehicle?

[DJRumpy]

I'm not implying they could get into orbit with this vehicle as it obviously will require atmosphere for the rotor blades to be effective, but in a general sense. Specifically getting a launch vehicle as far into the atmosphere as possible before switching to a different means of propulsion like a typical rocket.

Re:Earth to Orbit vehicle?

[Brett Buck]

But you can't possibly lift a big enough rocket with this little airplane. It barely works for tiny payloads when you drop the booster from an L1011. What this would amount to is far less effective than a rockoon, where a HUGE balloon lifted small rockets to ~100,000 feet. None of them came close to gaining sufficient velocity. Trying to raise the launcher 10-20000 feet ( at essentially zero velocity) is not worth the effort, no matter how big the lifting device is. This little thing is going to have problems even taking off with much more than a single person.

          Brett
             

Re:Earth to Orbit vehicle?

[bertok]

I'm not implying they could get into orbit with this vehicle as it obviously will require atmosphere for the rotor blades to be effective, but in a general sense. Specifically getting a launch vehicle as far into the atmosphere as possible before switching to a different means of propulsion like a typical rocket.

Achieving orbit is about speed ('delta v'), NOT altitude. It takes much more energy to get the horizontal speed to the required level than to reach the required altitude. Getting above the atmosphere helps, but not all that much.

Re:Earth to Orbit vehicle?

[DJRumpy]

From TFA: "the Puffin can lift a person with just 60 horsepower."

Again, I'm not saying this specific vehicle is what would be used. I asked if it could be a precursor to future designs. What is to prevent someone from putting higher HP electric motors? The scale on this one is tiny. Imagine putting a little muscle into this.

Re:Earth to Orbit vehicle?

[DJRumpy]

"The orbital velocity of a satellite depends on its altitude above Earth. The nearer Earth, the faster the required orbital velocity."

Is this accurate?

Re:Earth to Orbit vehicle?

[jensend]

Yes. What you need is for the force pulling you towards the earth to be equal to the force necessary to pull the satellite into a circular orbit rather than inertial straight line motion: G*m_earth*m_sat/r^2=m_sat*v_sat^2/r. So v_sat is inversely proportional to sqrt(r). Any faster and you'd be spiralling outwards; any slower and you'll spiral inwards.

Re:Earth to Orbit vehicle?

[TapeCutter]

"Specifically getting a launch vehicle as far into the atmosphere as possible before switching to a different means of propulsion like a typical rocket."

That's exactly what a 3 stage rocket is designed to do. There are no free rides in physics.

Re:Earth to Orbit vehicle?

[Anonymous Coward]

Getting above the atmosphere helps, but not all that much.

Not all that much?
Well yeah, depends on definition. If you try orbital speed without getting above the atmosphere, you have the choice of being atomized, melted and burnt, or decaying in no time plus being atomized.
If that's what you mean by not much.

Re:Earth to Orbit vehicle?

[Calinous]

There was a Pegasus rocket(?), launched from a B-52 bomber at higher altitude and speed than what this thingy is capable.
  Currently, the Pegasus (air-launched rocket) can put satellites of about 443 kg (1,000 pounds) in LEO.
      If this launch vehicle isn't as successful as other launch vehicles, I don't think why other similar ideas will.

Re:Earth to Orbit vehicle?

[Khyber]

"What is to prevent someone from putting higher HP electric motors?'

aerodynamic drag and thermodynamics, duh.

Re:Earth to Orbit vehicle?

[ZorbaTHut]

I suspect what he means by "not that much" is that it's necessary, but relatively easy compared to the rest. If you can do the hard part, you can probably do the easy part on your own.

This idea is like someone offering to help you run a marathon by telling you which way to turn at each intersection. Sure, it's critical - it's just easy.

Re:Earth to Orbit vehicle?

[hitmark]

that is basically what http://en.wikipedia.org/wiki/WhiteKnightTwo will do to http://en.wikipedia.org/wiki/Scaled_Composites_SpaceShipTwo

Re:Earth to Orbit vehicle?

[DJRumpy]

Yes, but not all methods are created equal, and quite a few are cheaper than solid rocket fuel.

Re:Earth to Orbit vehicle?

[mindstrm]

Exactly - the energy required to get out of the atmosphere is a very small portion of the energy required to actually reach orbital velocity.

Re:Earth to Orbit vehicle?

[camperdave]

No. Rocket staging has nothing to do with requiring different propulsion systems in different parts of the atmosphere. Rocket staging is about shedding weight and attaining velocity. The more mass you are trying to lift, the more propellant you require. The more propellant you require, the more tankage you need. The more tankage you need, the greater the mass you are trying to lift. Since, after a while, the tanks are mostly empty, why bother continuing to lift them? They aren't needed anymore. Divide the propellant into separate tanks, and when one tank is empty, ditch it.

Now, it's a lot easier to drop the tail end off of a rocket than the forward end, so you drop the engines and the tanks, then switch to a different set of engines. Coincidentally, once the first stage is done you've left the thickest part of the atmosphere, so it makes sense to switch from engines that are efficient on the ground, to those that are efficient in a vacuum.

So, the process isn't "Hey, I'm in a vacuum now, so I need to switch engines.", but "Hey, I'm carrying a lot of dead weight. Let me cut some loose.".

Re:Earth to Orbit vehicle?

[FiloEleven]

This didn't make sense to me until I scanned Wikipedia's article on orbital mechanics. It is counter-intuitive that lower orbits are faster and that increasing velocity will make you spiral outward. It turns out that firing a rocket to increase your velocity changes the shape of the orbit from circular to elliptical, so that the only point the two orbits have in common is the point at which you fired the rocket. In order to make the orbit circular again, a second firing must be done at the highest orbital point to lower the velocity.

Orbits are always elliptical, with circular orbits being a special case where both foci are the same. A change in velocity just changes the ellipse, but a constant acceleration will make you spiral outward.

Re:Earth to Orbit vehicle?

[phtpht]

A change in velocity just changes the ellipse, but a constant acceleration will make you spiral outward.

With enough change your ellipse will break up into parabolic and then hyperbolic shape. You will not be orbiting anymore, instead you will fly away.

Re:Earth to Orbit vehicle?

[complete loony]

You wouldn't spiral in either direction unless there was some other force being applied. eg atmospheric drag or rockets. If you had a circular orbit and suddenly increased your velocity, you'd now be in a more elliptical orbit, not a spiral.

Re:Earth to Orbit vehicle?

[TapeCutter]

"No. Rocket staging has nothing to do with requiring different propulsion systems in different parts of the atmosphere."

I didn't claim a rocket uses different propulsion for different stages. I was pointing out that the GP's idea of lifting something high into the atomosphere with something else is what rockets already do. For an example of something that does this with different propulsions methods you need look no further than a space shuttle launch.

Apart from a pedantic quibble over the word "coincidently", I agree with the rest of your post, there was no need for the strawman.

Innumeracy?

[gyrogeerloose]

From TFA:

electric aircraft are much quieter than regular planes—at some 150 meters, it is as loud as 50 decibels, or roughly the volume of a conversation, making it roughly 10 times quieter than current low-noise helicopters.

I admit that I never have gotten a handle on math beyond algebra but am I wrong by being bothered by statements like 10 times quieter? Wouldn't be better to say "makes only one-tenth the noise?" Or am I being pedantic?

Re:Innumeracy?

[Zerth]

just imagine "X times quieter" means x^(-1) the volume

Re:Innumeracy?

[Brett Buck]

I admit that I never have gotten a handle on math beyond algebra but am I wrong by being bothered by statements like 10 times quieter? Wouldn't be better to say "makes only one-tenth the noise?" Or am I being pedantic?

No, not as far as I am concerned. You are not being overly pedantic, even by local standards. It's a very awkward choice of words.

Re:Innumeracy?

[Sparr0]

If I make a noise of N volume, you make a noise of N-M volume, and bob makes a noise of N-3M volume, bob is 3 times quieter than you. Quiet is relative. Quieter is a measure of the difference between differences.

Re:Innumeracy?

[evilWurst]

You're not being bad. The "x times less" construct is really clumsy. IMO, it's mainly journalists and marketers using it; they're just punching (small new number) / (big old number) into a calculator, rounding it, and then the brain shuts off and they just say the new one is (result) times less.

The slashdot summary blurb is even worse, since sound is measured in decibels, which aren't linear. (IIRC, 3 db is a factor of two... so 33 db would be twice as loud as 30 db, and half as loud as 36 db). So if a normal helicopter was 120 db and the electric was 12 db and someone said "ten times quieter" they'd be very, very, very wrong. The actual article at least gives the electric volume as 50 db and compares it to the volume of spoken conversation, so you can at least ignore the potentially misleading math part in this case. Then again, it says that's the volume from 150 meters away... obviously it'd be much louder for the one flying it.

Re:Innumeracy?

[Anonymous Coward]

Yes.

And yes.

Re:Innumeracy?

[Anonymous Coward]

The article is right. The decibel scale is logarithmic, that means that X+3Db is double the value of X.

So, 10 times more than 50 decibel is 80 decibel, that's (to my knowledge) a pretty reasonable sound level for a standard helicopter taking off.

regards

Re:Innumeracy?

[Anonymous Coward]

Both. Pedanticism is a good thing, especially when drawing attention to exaggerations in advertising. Like when they claim "4 times more" and it's really "4 times as much" (so they should say "3 times more").

Re:Innumeracy?

[PPalmgren]

Thats like saying the flu is 10 times less lethal than AIDS, so it must be OK. Anyone with knowledge of how loud 50 decibels actually is, and relizes that thats at 150m, is probably with me in covering their ears near one of these things landing. A parking lot with these things would be deafening.

Re:Innumeracy?

[robot256]

Okay, you are right about decibels not being linear, but that's because neither is human hearing. dB = 20*log(X) where X is the power in watts and the log is base 10.

If something is 6db louder then yes, it is putting out twice as much acoustic power (in watts), but it would have to be putting out 20 times as much power (twice the total decibels) for someone listening to say "gee, that's twice as loud". And since "quiet" in this context refers to human perception, not acoustic power output, they would still be correct to say a 12db source is "ten times as quiet" as a 120db source--but the use of the comparative word "quieter" does confuse things semantically.

Re:Innumeracy?

[evilWurst]

I'm aware hearing isn't linear, having checked the wiki article on decibels before making the earlier post. But, checking a "common things in decibels" chart online, I'm not sure the scale reflects the perception of doubling either. A jet engine at 140db is a hell of a lot louder sounding than double a conversation at 60-70 db, and immensely more than four times louder sounding than a quiet library at 30 db. Even if that conversation were shouting in each others faces.

I'm thinking maybe it's more like 3 db is a doubling of air pressure reaching you, but 10 db is a doubling of perceived volume? I'm under the impression that the decibel scale is more of a means to compress the huge number range into something more easily handled (0-200 instead of 0-trillions) than to directly reflect how we hear it...

Re:Innumeracy?

[robot256]

The Wikipedia article on decibels states that it is fundamentally a unitless measure of comparison against some implied "reference level". That's why we can say an electrical amplifier has 10dB gain--the output is that much bigger than the input. According to the Wikipedia article on sound pressure levels, the 0dB reference point is the minimum threshold of human hearing. It also gives conversation as 40-60dB and the threshold of pain at 130dB. I agree that it is difficult to describe human perception of sound, not least because everyone is different, but I am starting to agree with you that 10dB could be a doubling of perceived volume, i.e., you could easily start a soft conversation at 40dB and "double" the volume to 50dB. I think we can agree that the descriptions of sound perception in general are of dubious objectivity.

Useless precision in ceiling

[the_other_chewey]

9150m are 30 019.685ft - so I presume the original source said
"up to about 30k feet", which obviously is an approximate number.

Although I salute the conversion to sensible units, the precision implied
is absolutely arbitrary.

"Up to about 9000m" is the number to give.

Re:Useless precision in ceiling

[vikstar]

At 9150m, a plane such as this which is 180kg + say 80kg human (260kg) holds about 23.34 Mega Joules of gravitational potential energy. Can 45kg batteries hold this much energy to push it up that high? (Not even considering the power required)

Re:Useless precision in ceiling

[Anonymous Coward]

Your Alpha link says that much energy is about 6500Wh, or 144Wh/kg of battery. I'd say that's well within the range of current LiIon technology.

dom

Re:Useless precision in ceiling

[fnj]

Ha. This is a pet peeve of mine. Useless and false precision. I am surprised they didn't say 9144.0 m (30,000 ft). Mind you, it will never make it to 9144.01 m.

Computer-Controlled (Re:Uncle)

[Tablizer]

and probably a challenge to learn to fly as competently as a good driver drives a car...I'm already concerned enough with a significant portion of the other people on the road. No way I'm going to share airspace with them too!

I suspect it wouldn't be sufficiently safe unless it was computer-controlled. It's not that I fully trust computers, just more than I trust everyday humans controlling flying machines.

Unlike most cars, proper proximity broadcasts and other requirements would allow the computer to have sufficient information to avoid collisions with other sky vehicles and high structures.

If there are mechanical problems, the computer could quickly check a stored map for the safest landing zones, such as empty fields or farms, avoiding populated areas. The pilot would be given full control only if the computer is unable to gain sufficient control over an emergency landing. (Extra control would be given to those with special or additional flight licenses.)
     

Re:Computer-Controlled (Re:Uncle)

[home-electro.com]

Computer to Pilot: We have an emergency, attempting safe landing... Ah, sorry, can't find a good spot. Controls are yours. You have 15 seconds until engine shutdown.
Piolt to himself: Oh, HSIT!

Re:Computer-Controlled (Re:Uncle)

[cdrguru]

A significant problem with aircraft - even commercial aircraft - is other objects sharing the same space without any sort of proximity information. Things like geese. Other general aviation aircraft without much in the way of equipment you would like to see.

All in all, you can't count on everything in the air cooperating. Absolutely, you can't make powered flight something that is blindly automatic.

Battery powered aircraft:Completely unrealistic

[viking80]

Li-ion-anything has an energy density equaling 1% of gasoline. Lithium phosphate batteries are worse than others in energy density, but safer.

So for the same fuel weight, instead of a 2 hour flight reserve, you would have 72 seconds.

Until there is a radically different battery, this is unrealistic.

Re:Battery powered aircraft:Completely unrealistic

[Anonymous Coward]

While I'm sure this concept is unrealistic for a number of reasons, only some of which I fully understand, I'm also pretty sure it's not that unrealistic. Consider, for example, that perhaps the engine required to turn gasoline into kinetic energy might weigh many times more than the engine required to turn electricity into kinetic energy. Especially if we start talking about the efficiency of that conversion.

Re:Battery powered aircraft:Completely unrealistic

[j_cavera]

Not unrealistic! There are a number of battery powered aircraft (that even hold people!) being manufactured today. Still kinda experimental, but getting much better. For starters, check out:

http://www.yuneec.com/
http://www.electraflyer.com/
http://www.pipistrel.si/planes/35

Yes, the energy density of the best batteries are about 5% that of gasoline (not 1%) but a gasoline engine is only about 20% efficient at converting chemical energy to mechanical. An electric motor is more like 90%. It's no where near equal, but definitely usable.

Re:Battery powered aircraft:Completely unrealistic

[timmarhy]

not really, you have to remmeber he is quoting gas, not AV gas which contains many times more energy again. unless your engine weighs 100 tonnes AV gas beats the piss out of batteries for energy storage.

Re:Battery powered aircraft:Completely unrealistic

[Anonymous Coward]

Av-gas is simply leaded gasoline. In the US, it is usually around 110 Octane, "low lead".

Re:Battery powered aircraft:Completely unrealistic

[Glonoinha]

Unless I'm mistaken, AV gas is pretty much regular gas with an octane rating of between 105 and 109. It's not nitro-methane or anything special.
When I was young and stupid I used to mix it about 50/50 with pump gas in my GSXR-750 and pretend to be a street racer. It didn't make much difference if any - for reasons that are obvious to me now, but back then I wanted to believe.

Re:Battery powered aircraft:Completely unrealistic

[jamesh]

According to TFA, the electric engine is ~95% efficient, vs ~20% for a gasoline engine. So we're up to nearly 6 minutes now :)

Re:Battery powered aircraft:Completely unrealistic

[viking80]

The efficiency of an Lycoming IO-540K1A5 peaks at 32%, and the Thielert Centurion diesel peaks at 40%. An electric motor peaks at around 80%, but controller etc has an efficinecy of at most 95%, and batteries can not be drained more than 74%, so the total is 64% usable energy. http://en.wikipedia.org/wiki/Energy_density#Energy_density_in_energy_storage_and_in_fuel/ lists Li-Ion with 0.5MJ/kg, and Gasoline at 46.4MJ/kg. http://en.wikipedia.org/wiki/Energy_density#Energy_density_in_energy_storage_and_in_fuel
That is pretty accurately 1%, and you are somewhat right in that when adjusted for system efficiency, the ratio is 2.1%

Still order of magnitude away for useful.

Re:Battery powered aircraft:Completely unrealistic

[viking80]

Av-gas has similar energy density as regular mo-gas. The higher octane rating allows for much higher compression, and therefore much higher engine efficiency and power.

Unless your engine actually have the compression to get this extra power, it is a waste of money.

Re:Battery powered aircraft:Completely unrealistic

[viking80]

Av-gas has similar energy density as regular mo-gas. The higher octane rating allows for much higher compression, and therefore much higher engine efficiency and power.

Unless your engine actually have the compression to get this extra power, it is a waste of money.

Nitro methane actually reduces the energy density of the fuel, but adds oxygen, so much more fuel can be burned in each stroke, thereby giving much more power.

Re:Battery powered aircraft:Completely unrealistic

[evilviper]

Li-ion-anything has an energy density equaling 1% of gasoline.

Water has even better energy density. Fuel and oxidizer in one compact package!

Re:Battery powered aircraft:Completely unrealistic

[Anonymous Coward]

It's bad, but not quite that bad. Electric motor efficiency is about three times higher than combustion engine efficiency. Electric motors are also lighter and require less infrastructure.

Re:Battery powered aircraft:Completely unrealistic

[evilviper]

From TFA:

This design relies on electric motors. These remain efficient regardless of their size, whereas internal combustion engines become less efficient the smaller they are. As such, electric aircraft can use small motors while generating impressive propulsion--the Puffin can lift a person with just 60 horsepower.

At up to 95 percent efficiency, electric motors are far more efficient than internal combustion engines, which only rate some 18 to 23 percent.

Re:Battery powered aircraft:Completely unrealistic

[mjwx]

Until there is a radically different battery, this is unrealistic.

Or a radically different power draw. Not every innovation is about more, the turbofan is better then the pulse jet because it uses a lot less fuel.

Re:Battery powered aircraft:Completely unrealistic

[msevior]

Actually Lithium-air batteries have a theoretical energy density of ~40 MJ/Kg which is about the same as Gasoline.

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

Of course these are a long way from commercial deployment.

Re:Battery powered aircraft:Completely unrealistic

[Anonymous Coward]

But remember efficiency of electric motors is 3-4 times that of (IC) gasoline engines. So ~250 seconds.

Re:Battery powered aircraft:Completely unrealistic

[Alioth]

Avgas is less energy dense than normal car fuel (only slightly). The only special thing about avgas is that it is nominally 100 octane, and it still contains tetraethyl lead (its proper name is 100LL - 100 low lead, although "LL" is relative - it has about 4 times the amount of lead as car fuel did when it still contained lead - 100LL has much less lead than 130 octane avgas, which is no longer made).

Re:Battery powered aircraft:Completely unrealistic

[mpe]

Electric motor efficiency is about three times higher than combustion engine efficiency.

Assuming you ignore the efficency of generating the power and getting it into a battery :)

Re:Battery powered aircraft:Completely unrealistic

[Anonymous Coward]

This isn't completely true. Electric motors have a much higher power to weight ratio then any reciprocating engine and can easily exceed 70% efficiency. These two factors allow electric powertrains to be quite competitive in some circumstances.

Re:Battery powered aircraft:Completely unrealistic

[ImprovOmega]

Which you would in this case because we're talking about stored energy : weight ratios in a closed system. It wouldn't matter if the power for the batteries was generated at 5% efficiency, it wouldn't change the fact that the energy density in the batteries is significantly less than that of gasoline, nor that your operational efficiencies are 3-4 times as high in an electric motor.

I do agree from a political perspective though, electric cars are not that good for the environment given what we currently use to produce electricity. Any gains you make in lowered auto emissions on your "green" car are canceled out by the extra coal being burned to power the stupid thing.

Re:Battery powered aircraft:Completely unrealistic

[fljmayer]

You are not counting the weight of the engine. An electric motor is much lighter than any gasoline engine or turbine. Therefore the energy density of an electric propulsion system is better than 1% of a gasoline system.

Re:Battery powered aircraft:Completely unrealistic

[Anonymous Coward]

are you including motor weight?

Re:Battery powered aircraft:Completely unrealistic

[Anonymous Coward]

Well, you can buy two battery powered 2-seater aircraft now, announced at Oskosh 2009. Endurance ~ 2-3 hours, 100km/h speed.

Poor design of tail

[ctmurray]

I think it is a poor design to have the plane "stand" on its tail. The picture shows the tail is "split" so it can help hold the plane in the upright position. Seems like this is ripe for damage to the tail and that can't be a good thing.

If it had a frikkin' laser...

[UttBuggly]

...I'd buy THAT for a dollar!

Actually, if this thing ever becomes an actual product, I'll buy one.

I can always get the laser in the aftermarket.

A Tail Sitter?

[westlake]

Tail sitters like the Convair Pogo were a beast to land.

The transition from horizontal to vertical flight has always come with substantial penalties - weight, complexity, power, control and cost.

There's some truth still to old adage that what "looks right, flies right." To my eyes this thing looks all wrong.

Re:A Tail Sitter?

[MichaelSmith]

I don't think this will be flown stick and rudder. More like point to a map location on your iPhone and press the "Go There" button.

Re:A Tail Sitter?

[jcr]

Tail sitters like the Convair Pogo were a beast to land.

That's because the pilot was on his back, looking straight up when the Pogo was landing on its tail. The Puffin would have the pilot in a standing position during takeoff and landing.

-jcr

Re:A Tail Sitter?

[westlake]

The Puffin would have the pilot in a standing position during takeoff and landing.

I'm still not convinced this gives him the visibility and control he needs.

The tail sitters spend most of their time in tethered flight inside a hanger. This ultralight tail sitter looks like it could be batted about by a heavy breeze.

Re:A Tail Sitter?

[jcr]

I'm still not convinced this gives him the visibility and control he needs.

It puts his head in the same orientation as a pilot sitting in a conventional helicopter (or a fixed-wing aircraft, for that matter). QED.

-jcr

Vegeta...

[Anonymous Coward]

...what does the scouter say about his altitude?!

Re:Vegeta...

[Alex Belits]

...what does the scouter say about his altitude?!

It says, gb2/b/.

Hard ceiling

[viking80]

Have installed aircooled equipment in aircrafts. Already at 5000m, air density is 50% of sealevel. Your cooling fan will have to suck in 200% of the air. At the same time, the rotors have to work harder to hold you up in the thin air. That requires more cooling as well. Maybe 300% at 5000m. At 10000m, maybe 1,000% increase.

You will quickly reach a hard ceiling. And with 60 seconds of battery life it is pretty theoretical anyway.

Japan got it first

[gmuslera]

This prototype really show how high we can get with personal flight vehicles.

Electric Planes

[__aazsst3756]

Very high quality realistic designs are already flying, one of my favorite is the Yuneec e430

Puffin looks like a...

[Anonymous Coward]

flying coffin that contains a supersized penguin that couldn't fit inside completely. Creepy.

Thank you, Google!

[_merlin]

PSA: don't blindly search Google if you want to find out what a "three-holer" is - I don't think any of the top hits are what he's referring to.

Re:Thank you, Google!

[Anonymous Coward]

There's your three-holer.

http://en.wikipedia.org/wiki/McDonnell_Douglas_DC-10

Cheers

Re:Thank you, Google!

[rossdee]

I didn't think there were that many DC10's flying these days, they had a bad image because of a spate of accidents (although most were not the fault of the aircraft, nothing could survive a head on with Mt Erebus )

Standing position

[Anonymous Coward]

Much like the Heinkel Lerche II.

It never flew either.

Cobra was first!

[Kostya]

Bah! Hardly original. Cobra C.L.A.W. anyone?

        http://www.yojoe.com/vehicles/84/claw/

Re:Just one thing...

[scdeimos]

I dunno, it could be a great source of material for the Darwin Awards.

nice penguin you have there

[vacarul]

oh look, a flying penguin! where's my riffle?!

Do I understand this correctly?

[Tibor the Hun]

It's late and I'm tired, but what they're saying is, if you be Puffin, you be flying high?
I'm down with that.

Darwin Lives!

[matt_hs]

With two prop electric engines, lithium phosphate batteries and a top speed of almost 300 mph

Ahhh, newer, faster, and better ways to auger one's self into the ground.

I see...

[DieByWire]

I see dead people.

fuel cells

[Anonymous Coward]

fuel cells

ummmm... Ultralights?

[Anonymous Coward]

One word: Ultralights. You don't need a pilot's license, most will fly ~100-150 miles on a tank and the lightest types can take off/land with only 200ft. Caviats however include no flying over densely populated areas, which will exclude most suburban/city work commutes. They're legal, and they're here today. However, it's highly recomended you get proper flight instruction before attempting to fly one ;)

more information on Ultralights

Re:ummmm... Ultralights?

[Anonymous Coward]

You don't need a pilot's license... However, it's highly recomended you get proper flight instruction before attempting to fly one

Actually, you do need a license, and it's not just recommended but legally required, at least in North America, that you get proper instruction before flying one.

In the U.S. you need a Sport Pilot Certificate. In Canada you need an Ultralight Pilot License.

Raven*s*

[xant]

Huginn and Muninn. I assume they're saving that for some sort of autonomous flying robot system that uses a pair of them to confuse enemy anti-autonomous-aircraft systems.

Hate to bump into something on accident...

[Megatog615]

I sure hope they put some sort of ring around the props(like a computer cooling fan) to keep them from striking near objects. I'm not saying I'm a terrible driver, but there are such people who can't drive worth a crap. If everyone had one of these I'm sure people would be bumping into buildings in their takeoff or landing procedures. Some sort of hard rubber bumper ring around the props(to prevent damage) would suffice. I'm not sure how it would affect flight capability though(I'm not an aerospace engineer).

Bad Drivers, Worse Pilots

[thzinc]

While I think the idea for the aircraft is spiffy, I'm not sure I like the undertones of "people will commute to work with this 'personal flight vehicle'." There are a lot of bad drivers out there, and I wouldn't want to encounter them while they're flying their PFV and talking on their cellphone.

Re:Bad Drivers, Worse Pilots

[zmollusc]

I would love these things to replace cars. Even with the retarded air-lane navigation that government would enforce to destroy as much freedom as possible, you wouldn't be delayed by a broken down commuter or a couple of vehicles that had collided.

Re:Bad Drivers, Worse Pilots

[rally2xs]

It would be beyond human capabilities to pilot these vehicles in the traffic densities necessary for commuting. This'll have to wait until the artificial intelligence is such that it can navigate the machines automatically, and the passenger can sleep all the way to work. Or wherever.

i'm still waiting on my jet pack

[sneakyimp]

i'm still waiting on my first jet pack and this article is trying to tell me jet pack is obsolete. what a bummer. to be honest, i'm imagining this vehicle will result in a lot of strained necks. it looks very uncomfortable.

Cute Flick, But Icarus?!

[LifesABeach]

Gasp! I RTFA. I would love to fly over the grid lock of the 405 Freeway during rush hour; please NASA, don't screw the pouch on this one; (maybe after this project, NASA can stop playing around and get back to sending us to the moon?) The flick looked cool, but what/where are the specifications?

Re:Cute Flick, But Icarus?!

[T.E.D.]

If everyone was doing it, you would end up changing traffic (and avoiding accidents) from a two-dimensional problem into a three-dimensional problem. There would still be the same number of people involved.

That is not an improvement.

Re:Cute Flick, But Icarus?!

[LifesABeach]

I don't see a lot people doing buying one of these. But i do see a few people doing it. When people realize that flight is like sailing a boat, but in 3 dimensions, and in a medium that's a lot thinner than water, they tend to find other pursuits. As for me? I hate Traffic.

Strange use of technology...

[Sk1dmark]

If the batteries are that good, why not put them in a car and solve some of the environment problems?

Battery powered aircraft

[Make]

The Antares 20E made its maiden flight in 2003. It is a self-launching glider with battery powered engine:

http://www.lange-aviation.com/htm/english/products/antares_20e/antares_20E.html

A wonderful glider. Sad it's so expensive (several 100k euros).

And we'll never be allowed to have one

[Leo Sasquatch]

Go read Bob Shaw's 'Vertigo'.

The changes this would make to society are too great. The politicians would never allow common people to have that much freedom. No borders, no passports, no way of stopping people from going where they wanted, when they wanted. And that's without assuming any purpose more nefarious than a cheap weekend in Amsterdam.

One asshole with one of these and a pocketful of golf balls could cause carnage in a city centre at rush hour - no way to track or find the culprit afterwards. As long as there's idiots who think throwing rocks off motorway bridges is a fun thing to do, there'll be idiots who'll be delighted to abuse this even worse. Drug dealers, criminals of any kind who want to make a clean getaway (get 10 feet off the ground and nobody's catching you, no matter how fast the police car).

It's not the physics of flight, or fuel capacity, or engine efficiency that will stop us ever getting personal flight vehicles - it's the politicians who will legislate it out of existence for all but the very rich, because whatever rich people want is always all right. And they'll do it in the name of safety, and it'll be for our own good. There'll be a huge furore in the media when the first one crashes and kills someone, and that'll be it done with.

Re:And we'll never be allowed to have one

[alobar72]

The politicians would never allow common people to have that much freedom. No borders, no passports, no way of stopping people from going where they wanted, when they wanted. And that's without assuming any purpose more nefarious than a cheap weekend in Amsterdam.

I wonder if there was someone a hundret years ago, who said something like this about cars.... I think, if you put some technology into those thing - most of the problems you adress could be solved. Could be some kind of electronically "check-in" when entering special areas or such... come on... I realy _want_ this :-)

Re:And we'll never be allowed to have one

[mcgrew]

The changes this would make to society are too great. The politicians would never allow common people to have that much freedom. No borders, no passports, no way of stopping people from going where they wanted, when they wanted.

That sounds like the internet, only the internet is more so, and back when Murray Leinster wrote A Logic Named Joe (Full text of the story at the link, it's a good, albeit dated, science fiction story) they would have said the same thing about the internet then if anybody could have believed such a thing could ever be developed.

One asshole with one of these and a pocketful of golf balls could cause carnage in a city centre at rush hour - no way to track or find the culprit afterwards.

One asshole with a pocket full of golf balls could do the same thing from the top of a tall building, only more easily.

there'll be idiots who'll be delighted to abuse this even worse. Drug dealers, criminals of any kind who want to make a clean getaway (get 10 feet off the ground and nobody's catching you, no matter how fast the police car).

The police won't be allowee to use these? The same could have been said of the automobile when it was new. Besides, didn't you see Star Trek where the cop outruns young Kirk, who is driving a vintage Corvette, with his flying motorcycle?

Capt. 'Cannonballs' Kittinger

[rts008]

Wow! And I thought I was nuts for loving HALO[High Altitude, Low Opening] jumps!
[With full equipment/kit load+body wt. @ around 275 lb./125 Kg] I was told that the max. velocity was around 130 mph/209 kph...compared to 714 mph, I guess I was a piker!

Offtopic side note:The highest we ever jumped from was around 17,000 feet altitude; I found my minimum altitude for releasing my chute was approximately 385 feet, but it hurt!
(we were advised that the minimum altitude was 500 feet...I had to test this)
[using the US Army version of the Ram Air-square type 'chute]
That was also where I got over my fear of heights, once I was thrown out of a perfectly good airplane!

Re:Capt. 'Cannonballs' Kittinger

[Zordak]

I found my minimum altitude for releasing my chute was approximately 385 feet, but it hurt! (we were advised that the minimum altitude was 500 feet...I had to test this)

So are you still chasing that Darwin Award, or have you given up ;-)

The props don't look large enough...

[Viol8]

... to do any serious auto rotating. Or at least enough to prevent you hitting the ground without leaving a small crater. To me this machine looks like a death trap if the motors fail - wings too small to glide , little auto rotate from props , and thats assuming you could even get it vertical to achieve auto rotating while its plummeting to the ground nose first.

If I was a pilot of one of these I'd make damn sure I had a parachute!

Re:The props don't look large enough...

[robot256]

As a model helicopter pilot, I agree. Autorotation requires a high moment of inertia in the rotor assembly, and a prop 1/3 the width of a normal heli will have ~1/27 the inertia (1/3 the mass, 1/9 the moment). So you would get only ~7% of the autorotation lift as in a comparable single-rotor heli. (For the uninitiated, autorotation is a method of emergency landing where kinetic energy while falling is stored in the blades, then released as lift shortly before hitting the ground to stop the fall.)

Also, if you look closely at the transparent views in the video, you can see that each prop is actually powered by four smaller motors all driving a central gear, not unlike some miniature flying toys that use pager motors. So if one motor burned out the other three would still be able to drive the prop.

That said, you are quite right, those forward-swept wings will be impossible to glide with and there's basically no way to control orientation without the props. Maybe that's why they are talking about adding redundant prop assemblies and such--so that it will be safe enough for a human to actually pilot.

One-man!

[Catmeat]

The Puffin is an all-electric one-man airplane

So are only men allowed to fly them? Or does the technology require the pilot insert a weiner into something to get it to work; thus making it impossibly to fly for those who are weinerless.

- Catmeat (weinerless hang-glider pilot)

Re:One-man!

[Anonymous Coward]

I'm sorry about how the English language works. Oh wait, no I'm not. And I also have no weiner.

You must be a ton of fun at parties.

Re:One-man!

[Anonymous Coward]

Well, there was no room to put a normal flight stick so...

Re:One-man!

[MooseTick]

This has nothing to do with weiners. The DRM in the plane uses a chromosone detector to ensure only men can drive it. I'm not sure how this works out when the man is wearing a lady wig though.

Re:One-man!

[mcgrew]

So are only men allowed to fly them? Or does the technology require the pilot insert a weiner into something to get it to work; thus making it impossibly to fly for those who are weinerless.

A wo'man is a man with a womb, and your militant feminist attitude insures that I won't be asking you out, lady. I pity you.

A side note -- there is no such thing as a sex change operation. Removing a man's penis and testicles and implanting breast implants and injecting him with hormones that removes facial hair does not make him a woman. He still has a Y chromosome. Which, I doubt, you need to fly one of these things.

Battery technology

[mrjb]

As long as I see the batteries in my electric toothbrush, navigation system and laptop fail to hold more than a minute worth of charge, I'd rather not get off the ground too far in one of these.

Re:Battery technology

[mcgrew]

As long as I see the batteries in my electric toothbrush, navigation system and laptop fail to hold more than a minute worth of charge

Huh? My six dollar toothbrush uses two AAA batteries, and they last six months even though I use the thing three times a day. You either need a different brand of batteries, or different brands of the devices they work in.

Extreme Sports

[zigge]

this opens up the opportunity for loads of new extreme sports!

Colombia

[dimethylxanthine]

a personal aircraft that will put jet packs to shame

This is also going to put to shape low-depth colombian cocaine transporting submarines and ones this gets popular with terrorists will give the DHS one more reason to to warrentless searching and nuking of any MEHV's. That's, of course, unless terrorism and illegal drug trafficking become obsolete...

It's good to know...

[Anonymous Coward]

... that NASA is still hard at work on some General's wet dream. :(

I will eat my hat if this thing ever makes it to production.

When can I buy one from FORD, GM or CHRYSTLER

[Anonymous Coward]

I'd never trust my life to a vehicle made by the lowest bidder, sold for the lowest price, from substandard parts sourced from China. Meanwhile, "The Big Three" really need to come up with something that revolutionizes transportation, and this could be it. Don't forget that they've built and sold transportation products, and have much lower opportunity cost than Wally World does.

Big planes are more practical

[bjourne]

Can anyone explain why NASA is focusing on a small personal aircraft instead of a jumbo jet? It seems to me that an electric plane that can be used for mass transport would be much more practical, and have a huge market. Practically every airline would want to replace their petroleum dependant aircraft fleet with electrical ones which would be much cheaper to operate. Plus, a jumbo jet would be easier to get efficient, just put a really large battery in it, right.

Re:Big planes are more practical

[rally2xs]

Having just flown LA to BWI for 5 hrs or so, I'm not fond of contemplating flying propellor aircraft, which an electric almost certainly would have to be, that far. Make airliners to be powered by scramjets - that I'm interested in - but for prop stuff, lets stick to commuting to work. This'll be practical when we get the true autopilot, that you tell where you want to go, and it gets you there. IOW, AI to the max.

Stealth vs. rotors; rotary-wing vs. fixed-wing

[phyzz]

I fail to see how this aircraft would be stealthy, even being built with composite material. The huge propellers would shine like hell on a Doppler radar's scope.

Furthermore several two-place fully electric aircraft exists already, they are certified as Light Sports Aircraft, and so have by nature VSTOL capacity by nature...

People tend to forget that the only advantage of the helicopter (or any powered rotary-wing aircraft, excluding autogyros) is the capacity to hover. In all other cases, fixed-wing aircraft are superior in speed, endurance, range, safety, etc. (trade-offs being made to allow either low stall speeds or high dash speeds or high operational altitude or heavy cargo capacity or oversized cargo capacity or CowboyNeal transportation...) You could land some VSTOL aircraft in half a football field, and take off with some restrictions.

Wheels?

[joeslugg]

Why does it show it having wheels? I can't see from the demo video how/when the wheels are used.
OTOH, I'd like to see how one moves this to storage (e.g. hangar .. er, garage). Maybe you tilt it and
push it in, something like a utility dolly.

Maybe the focus is more on building a working prototype before worrying about such mundane details.

Maybe I should stop asking questions and end this post.

Maybe.

Will you stop already?

[Quiet_Desperation]

Just stop with these promises of personal flight stories. It's been promised on a weekly basis since the Wright boys converted the bike shop, or maybe even the first Montgolfier balloon. You think the FAA is going to let it happen? The PILA? (Personal Injury Lawyer Army). Most people's inability to move safely in just one or two dimensions much less three? This will be a toy that some billionaire plays with before getting bored or cratering, and maybe the military will be interested for about a month.

hideous

[volt4ire]

and I thought jetpacks were ugly...

Worthless Press Release

[Anonymous Coward]

The initial posting is a complete waste of time and electrons.
This NASA project has no hardware, it is a press release.

60 HP is not going to get you 300 kTAS, even at 30,000'

There are several already flying homebuilt electric aircraft that
have flown at large gatherings of pilots, like Airventure (Oshkosh)

Is it just me...

[OneSmartFellow]

... or does that thing look like http://www.sacredart-murals.co.uk/images/Mural%20Rooms/Shrek-ToyStory-Monsters-inc/shrek_06.jpg

Excellent design

[xednieht]

It is very conveniently designed with a dual purpose - VTOL and coffin. Rip off the wings and you could be buried in it.

20 minutes is plenty enough...

[Anonymous Coward]

...flight duration for James Bond 007 to make his getaway from Dr. Whacko's lair.

Puffin

[ISoldat53]

I wonder if they looked up anything about a puffin. It is a notoriously bad flier. They don't all them scuba pigeons for nothing.

air traffic control

[stefski66]

I want it... as long as I'm the only one: imagine a large city full of people wanting to benefit from individual flight transportation. What a mess. That's why we have ATC.
And you know what ? we'll have flight routes, which will be overcrowded like ground road, and you will still be a 2h-commuter, just way farther in distance.

So no, it's not a commuting solution. However, I leave 1h30 from the sea, it can be cut to 15 min with this thing...

Interesting

[Anonymous Coward]

This looks a lot like the Convair "Pogo" tail-sitter concept that the USN experimented with in the 1950's.It had major technical difficulties and the project was dropped as unworkable. The prototype only flew tethered and never went through transition from vertical to horizontal flight. This does not look like something that the average person could get into and go like an automobile, probably requiring (at the very least) a helicopter license (I don't think fixed-wing training would cut it).

It is interesting concept however, I wonder if you added an engine/generator and make it a kind of hybrid with the generator running the electric engines until the fuel was exhausted and then the batteries would take over. Would the extended range be worth the added weight and slight redesign?