Can we achieve practical personal flight with current options?

[hyteck9]

Hello to all,
This is my first post, other than the introduction of course. I want to talk about personal flight options. I have searched in, and external to, this forum and understand there are various types of options currently available. However I'm not sure they are truly practical to usher in a new era of personal flight. The Martin Jetpack is just enormous with limited direction and range and JetMan can't really take off and land as one would going to and from work every day. So how do we take it to the next level of usefulness? By asking good questions, that is how. Let's focus on individual components of the engineering and build up, rather than deconstruct what others have done top down. A few categories to get started:

Power source: electric , liquid fuel, solid fuel, other? Why? Weight vs. work potential? Practical availability and cost?

Thrust mechanism: Rotor, turbine, rocket? Why? Safety over size? Control and agility over speed?. What about a combination?

Form factor: Backpack , minimalist pod, flying car? A backpack or open cockpit is only a good weather device, but would flying cars be grounded in bad weather anyway, either by FAA or common sense of self-preservation?

I will define practical flight as a 15 minute minimum flight time with easy take offs and landings, plus it must fit in a 10x20 parking space.

I think that is enough to get started on. Please feel free to chime in on any or all of the subject areas. Support your choice logically and/or highlight what is holding us back in a certain area with examples. (this is fun!)

 

[timthereaper]

Are we assuming that personal flight is a viable option? Because I don't for a variety of reasons. But with that assumption:

• Form: I would think aerodynamics and basic safety would rule a jetpack out. It might have to be a flying car simply because you might want to pack stuff with you if you're going anywhere appreciably far away.
• Power source: Until newer technologies develop, gasoline is really the only thing that's affordable enough with enough energy density to get everyone places. That's the real problem with trying to get away from fossil fuels. Electric will be better, but until you can make something more energy dense than the lithium ion battery, you're stuck to black gold/Texas tea.
• Thrust mechanism: There's been too much research into turbines to make it much else commercially viable. Safety is the biggest issue and I can't see a company risking it all on a new technology that hasn't been proven. Plus, I can't see anything else competing for efficiency. Turbines are getting more efficient all the time.

IMHO, the real barriers are non-technical. There are a lot of other problems you have to solve first in order to make personal flight vehicles a practical reality.

 

[hyteck9]

IMHO, the real barriers are non-technical. There are a lot of other problems you have to solve first in order to make personal flight vehicles a practical reality.

Thanks for the reply. Please elaborate on the hurdles you perceive. I'm interested.

 

[timthereaper]

Like I said, the problems are non-technical:

• Complexity: Some people have trouble driving a car constrained to a flat plane. Think about your daily drive. How many people do dumb things all the time when you drive places? Cutting people off, speeding, going reeeallllyyyy slow. If some people can't control a vehicle in 2D, adding a third dimension would just blow their minds.
• Safety: With flight, you can't have a fender-bender. It's really all or nothing. Making a vehicle light and strong enough to survive a crash are almost exclusive to each other (I said almost). Modern cars can handle crashes, but that's at 55 mph. Imagine adding a fall from some height above 400 feet.
• Police: Staying on a predetermined flight path would be hard to enforce because you know there would be some idiot that would veer off to "explore". With the sheer number of extremists out there, flight just offers another way to cause mayhem. Plus, how do you "pull over" or set up roadblocks for a plane?
• Distractions: We can't get people to stop texting and driving. Texting and flying?. Flying under the influence (FUI)? I shudder to think.
• Maintenance: maintaining a car is tough enough for some people, but making a vehicle flightworthy is SO much harder. Plus, pilots are ultimately responsible for the vehicle they fly in. I knew experienced test pilots that died because they didn't realize the maintenance crew installed some of the control surfaces upside down. Experienced test pilots. Can't imagine Joe Blow doing a diligent preflight on a daily flier, especially if he's late for work. Some people don't even scrape the ice off the windshields on cold days.
• Distance: Planes burn up a lot of fuel during takeoff and climbs. To make it worth that fuel cost, you'd have to be traveling pretty far.
• Air traffic: Air traffic control would be hard. It's hard enough with as many planes take off from certain regions. Can;t imagine how congested things would get by adding even 2-3x the number of vehicles. Even though you could add more regional airports, you'd still have to deal with the air traffic routes around the city. You can't just take off, land, and fly over any part of the city you'd like.
• Infrastructure: You'd have to regulate all the air traffic somehow. That would necessitate more air traffic controllers, more airports, more FAA (!), etc. We have trouble maintaining all the roads, bridges, tunnels, etc. for cars. I can't see us pouring money into infrastructure for flight. Also, there would have to be a better regulatory system for licensing than for cars. It's not a major hurdle, but there would definitely be more pilots than now if flight was more affordable.
• International air traffic: Mainly for people who live close to other countries. How would you make sure Florida pilots didn't "accidentally" fly into Cuba? Or Cuban pilots into Florida? Or South Korean pilot into North Korea? It would cause an international incident.
• Vehicle Cost: This veers a bit into technical, but if all the relevant systems were installed and safety features were in place, would this end up costing more than just owning a car AND a plane separately? Plus, if you want the car to drive as well as fly, you'd have to make an internal combustion engine drive a turbine, or a turbine power a drivetrain. Or maybe have both, but then you'd never get it to fly because of weight.

There are probably more than these concerns, but I can't think of anything else right now. IMHO, if you can solve those problems, then the technical ones will be a breeze.

 

[hyteck9]

ah ha! Now this is fun stuff to talk about. :) Thank you for talking the time to type out a detailed response. I actually feel technology 'can' solve a lot of those issues. Other solutions may require a departure from our current flight standards. Here are my initial thoughts.

Complexity to operate: I would offer that tHis can mostly be solved by technology with features like intuitive controls, auto hover, even object avoidance and other such features are now found in toy drones. I Agree that different government licensing would be required to make sure the person is capable.

Infrastructure, Air traffic, police: Perhaps what we need is a system designed to work within itself. All vehicles are software capped at max alititude of 400 ft, GPS tracked, aware of other vehicles + the afore mentioned object avoidence and "emergency zones" etablished for landing vehicles who's computers read anything out of spec. Police can also "OnStar your ride" and kick on the emergecy zone protocal forcing the vehicle to land. Sure, any software can be hacked, but bad people will always do bad things.

Safety: I think with advanced features, proper licensing, and inteligent diagnostic onboard systems it is about as safe as one could hope for. People die in car crashes all the time, but cars have very limited 2D options to get out of the way too.

Maintenance: I had not speficically considered this, but as part of the licensing I would think a vehicle inspection is needed, perhaps annually. If the vehicle is not reliable to make it a full year for an inspection, it is a design flaw.

Cost: Tesla is selling electric cars for $120k and people are buying them. Is that practical? hard to gauge this question at this point I think.

 

[berkeman]

Seems like the most practical possibility would be a gasoline-powered ultralight aircraft with some folding/compacting capabilities. It would be a good idea to enclose the prop in a cage, and use computer flight and navigation controls, so the person using it did not need to be a skilled pilot.

That would still require some organization of places to take off & land, but things like sections of parking lots could be used for that, perhaps.

Something like this:

http://www.learner.org/jnorth/tm/crane/ultralight_weight_shift.html

 

[Baluncore]

Safety requires reliability under “loss of power” conditions. The solution is available now, it has been developed over the last 150 Ma; called birds, they have two wings and a tail. Efficient personal flight will require an efficient wing, as a powered glider. Present machines need have propellers and fast IC engines to keep the weight down. With time, variable geometry wings will become more common. Then, as efficient propeller speed falls we will reach the point where flapping the wings will become a better and safer solution.

Fuel will always be a problem. Aviation up to now has been dependent on liquid fossil fuels. A change to something like ethanol or hydrogen can be expected. The engines or actuators that convert fuel to movement will change once flapping wings appear.

 

[Wes Tausend]

hyteck9,

A recent PBS episode (Ep 4, Season 5) of The Aviators included a segment about Jet Man (Yves Rossy) and a jet-powered strap-on wing he wears for airshows. The carbon wing straps on like a backpack and is powered by four Jet-Cat P200 jet engines modified from large kerosene-fueled model aircraft engines. Rossy can do aerobatics, including loops. He launches from other aircraft.

The most significant part of this for you may be the modified jet engine innovation since it seems a slower "commuter" craft might more practically fly with two engines (or one) with at least twice (or four times) the range.

Links: http://en.wikipedia.org/wiki/Yves_Rossy, http://www.jetman.com/



=====================================================================================================
A related arial quick get-to-work method might be a self-powered cable-car network strung diagonally above cities. I suppose traffic blending first-come/first-served like the freeways below, only suspended by cable.

Steering concerns are removed if the cars automatically "switch track" (cable) on a predetermined route demand. Remaining movement safety then becomes a matter of adapting ordinary train anti-collision that has come into vogue as of late. As a compromise, high speed cables may cost less than concrete and be more reliable than sky hooks hooked to stormy, wandering air, yet offer an exciting ride. Of course wear on the cables could be greatly reduced by super-cooled magnetic levitation while we are imagineering.

Wes
...

 

[256bits]

Form factor: Backpack , minimalist pod, flying car? A backpack or open cockpit is only a good weather device, but would flying cars be grounded in bad weather anyway, either by FAA or common sense of self-preservation?

One does not see too may birds, if any, flying in bad weather.

Planes will have the all clear ( and this is from a combination of input from the aircraft company, air traffic control, the airports-ground control and pilots ) on whether they can takeoff. It is not just the weather at your own location that is pertinent, but also the weather at your destination. Even with a short distance hop of only 15 minute flight, local weather patterns would have to be known.

Wind, rain, snow, icing, freezing rain, fog, nighttime are all going to play into the decision to takeoff or not. The preparation time could jump drastically in a lot of cases.
Freezing rain for example is combated at airports by the showering of the plane with several de-ice mixtures ranging from the cheaper to ultra expensive. Would a personal user know how to apply, and have the storage space available for the liquids.

I would imagine that, when it is all said and done, only about 100 days out of the year, depending upon location, would be conducive for an owner to be able to fly with his personal craft without undue pre-prep, regarding the weather.

 

[Bobtitus2]

I've always wondered why a small helicopter wouldn't incorporate an articulated nacelle surrounding its blades. This should improve efficiency and safety while allowing for the use of vectored thrust for directional control (in addition to the rear rotor and main rotor articulating blades). This could also allow for the stacking of rotor blades, the primary purpose of which would be to maintain required thrust within a smaller diameter while reducing the weight of the nacelle itself by making it smaller. I believe the primary issue with this has been one of added mass, but the use a lightweight alloy or an FRP (epoxy carbon/Kevlar/etc.) might change that equation, along with the cost equation too. Of course, the use of a nacelle might also reduce the area of unintended incidental impact, and so reduce the surprisingly rare incidental rate of decapitation, which would become a much more important safety factor when parking/landing in midtown Manhattan. Which also brings up one of the primary issues of mechanical man in flight, the safe landing, which many aviators define as a controlled crash, and which might well be a situation that would always require some sort of dedicated/independent ground facility specifically equipped to deal with large man made objects falling from space...see recent Space X barge booster landing...
I think the surprising lack of large scale public engagement in general aviation has a lot to do with this specific function, and that most folks who've controlled a plane find the takeoff thrilling, if not transformative, the elevated view of the world around them inspiring and that flying something like a light plane into the ground is counterintuitive at best, and damned challenging (frightening) in a gusting 40MPH crosswind. So I'd say that conquering that matter would be perhaps the primary challenge, which might be well addressed by the emerging, or merging technologies associated with the autonomous (pilotless) automobile (vehicle). And a helium inflated parachute.
Which gets me around to the 'flying parachute', which might be the best option currently available, due in part to the fact that's basic functioning design relies on the alternative to an impossible landing, and it lands at walking speed, literally. BT

 

[johnbbahm]

Someone was trying to build some vertical takeoff gyro copters a few years ago,
one used ram jets at the ends of the blades, the other weights.
The weighted blades would be feathered and spun up using axillary power from the
pusher engine. Once up to speed the blades could tilt to catch the air, the
inertia would jump the craft about 70 feet in the air.
I bet it would be a thrilling ride!
I found a youtube of this actually working,

 

[Baluncore]

I bet it would be a thrilling ride!

“Practical personal flight” must be safe, economic and quiet. Unfortunately, any exciting mode of transport will be dangerous.

Gyrocopters / autogyros have not yet stopped killing their operators. The insurance of an autogyro costs more than the fuel. Ram jets at blade tips are certainly not quiet. I have a couple of blades from an autogyro that show where some of the rotational energy goes when there are problems while still on the ground.

In transport systems, conversion of stored energy is always going to be a problem. The faster you travel, the more kinetic energy you must convert when stopping. The higher you fly, the more potential energy you must convert when landing. "Engine" power is the maximum rate of energy conversion.

Low bridges permit traffic flow to cross without risk of collision. Railways and bicycles are relatively safe, economic and quiet. Is there yet an equivalent mode of flight available?

If motorised road vehicles cannot be operated safely by “normal” people, then what hope can there be for flying machines?

 

[hyteck9]

These are all great posts. Allow me to respond to each of these posts.

Berkeman,
The ultralight idea is a very good concept. If it could be enhanced with vertical take-off, and folding/collapsible wings for parking and storage its not a bad way to go. How would you propose to resolve this?

Baluncore,
The loss of power issue I think is best handled with a parachute. They are simple, small, proven over time. No reason not to have one as a last resort.

Wes,
I like JetMan. But he can't take off or land under his own power, the two biggest hurdles to overcome. How would you propose to resolve this?

256,
Mechanical flapping wings are an amazing thing to think about, How would you implement this? Is wing span alone impractical for taking off in congested areas like a driveway?

BobTitus2,
Can you elaborate or provide a sketch of what you are envisioning? I think I have it, but I would like clarification.

John,
That is a great find. Thank you for the link. I would imagine that vertical takeoff method is "single-use only" then the ramjets must be replaced. Can you think of a way to make it a maintenance free and repeatable?

Baluncore,
You have raised several questions about noise, energy and transportation infrastructure. I agree noise is a concern for residential areas. Energy and infrastructure have been talked about a little bit in the threads above, Do you have any proposals for resolving them as well?

To all I will say:
Bad weather is a real hindrance, I totally agree. It would take considerable technology combined with an abundance of power to make bad weather travel easy. I would propose a computer stabilization method using airspeed sensors on all sides mated with fine-trim thrust devices, all operating in a rather seamless fashion to the average user. Not impossible. but very tricky.

 

[johnbbahm]

The ram jet gyro as I recall just burns the fuel the gyro uses, (all be it lots of it)
The weighted rotor has power clutched from the pusher engine.
both are repeatable, the weighted rotor just requires spin up time.

 

[DaveC426913]

albeit :)

 

[jack476]

I think there are more important non-technical considerations.

If your car runs out of gas, you just come to a stop and you are only at risk if you are in very heavy, fast-moving traffic. If a plane, even a small one, runs out of fuel, you can still control your descent and glide to a safe enough landing. A helicopter goes into auto-rotation if it loses power and the pilot can still control the descent safely enough for a non-lethal landing. If a jet-pack runs out of fuel, you plummet to your death, unless you're at a high enough altitude to feasibly deploy a parachute.

So any failure of the jet pack will likely result in death or at least possibly severe injury for any useful speed or altitude.

Then there is the nature of how people will control their jet packs. Unlike on the ground, in the air there are no brakes. Unless you can turn fast enough without stalling, you have no way to avoid a collision. Jet packs have no lift so a very quick turn may kill enough forward momentum to cause you to fall unless you can accelerate fast enough in the new direction.

So I don't think we'll be seeing exotic solutions like jet packs or rocket pods.

Ultra-light fixed-"wing" aircraft I think would be the solution for personal flight. If memory serves there are ultra-lights that cost not much more than cheap cars. However, they still need a take-off and landing strip or at least enough open space, which might make using them for your morning commute a little difficult, unless a VTOL ultra-light is invented. They're rather limited in range and I think there are some rather stiff legal restrictions regarding their use, but I think that's our solution.

 

[Baluncore]

The weighted rotor has power clutched from the pusher engine.

Since a gyro has no tail rotor to counter the torque, that coupling is only possible during initial "spin-up" on the ground.

If ram jets at the tips of an autogyro's blades are used then you have a helicopter and the airfoil angle of attack must be reversed. A helicopter requires a swash-plate to control pitch. An autogyro flies forwards with nose up so air flows up through the blades causing them to "auto-rotate". The autogyro blades are then effectively gliders providing lift. A helicopter flies forwards with nose down as the blades push air down and backwards. The transition between those distinct modes is quite dangerous as the vehicle must fall through the low airspeed period without lift while the blade angle of attack is reversed.

 

[hyteck9]

It seems like a good portion of this thread is focusing on "fixed wing" or not. Yes, a fixed wing craft can glide to the ground with some hope of survival. Add a parachute to a non-fixed wing craft, and I feel it has an equally if not higher rate of survival. Does everyone agree with me?

Fixed wing craft typically do not VTOL which I feel is a huge part in making personal flight practical. Does everyone agree with that?

Parking / Storage is another issue all together. folding wings could be a solution, but true fixed wings just won't cut it. Agree?

If all agree, do we take fixed wing craft off the table then as a solution for practical personal flight?

 

[Baluncore]

If only things were that simple. If “fixed wing” is the enemy then you must define “fixed wing” before targetting "fixed wings" and making them the scape goat for all other failures. The human need for a common enemy leads to racism and genocide.

It seems like a good portion of this thread is focusing on "fixed wing" or not. Yes, a fixed wing craft can glide to the ground with some hope of survival. Add a parachute to a non-fixed wing craft, and I feel it has an equally if not higher rate of survival. Does everyone agree with me?

No. For some reason parachutes are not widely used on helicopters. Gliders are still safer than parachutes.

Fixed wing craft typically do not VTOL which I feel is a huge part in making personal flight practical. Does everyone agree with that?

No. Crows cannot take off vertically, they use a hop, a skip and a jump. Why are we different?

Parking / Storage is another issue all together. folding wings could be a solution, but true fixed wings just won't cut it. Agree?

No. Storage is not a deciding factor. Some aircraft on aircraft carriers are fixed wing, some are folding wing and some are helicopters.

If all agree, do we take fixed wing craft off the table then as a solution for practical personal flight?

No. We will evolve a practical technique by keeping our options open. Birds are a good example of that. Eliminating fixed wing eliminates the quietest, safest and most efficient options yet found. Fixed wings are necessary as the migration path to better solutions.

 

[hyteck9]

I do not consider birds to be fixed wing. They are folding wing and flapping wing. better for both storage and VTOL.
My definition of fixed wing is just that. A fixed inflexible unchanging wingspan.

 

[Baluncore]

There are fixed wing VTOL aircraft. It is irrational to eliminate “fixed wing” because you feel a need for VTOL.

VTOL is inefficient and wastes energy. It is irrational to require VTOL for practical human flight when the most intelligent birds, namely Crows, do not require VTOL.

 

[hyteck9]

OK, I will not make it a requirement, rather I will post the question which in my mind that makes it a requirement and ask you to provide a different solution.

Here is my idea of a "practical personal flight" day.
How would you propose on a nice sunny day, 5,000 people lift off from their suburb homes, head to work downtown, land and park their personal flight craft .. all during the 8am and 9am rush hour? There simply isn't enough time to queue them all up on a runway. If they cound vertical land on the tops of buildings, parking garages, grassy picnic areas, etc. It seems more feasible in my mind. What do you envision?

Also I will continue to point out that the crow can fold its wings once on the ground. It makes a smaller personal space for the bird. This makes it easier for the bird to maneuver on the ground and protects its wings from damage. I would strongly support a design that at least folds up the wings for these reasons.

 

[Baluncore]

How would you propose on a nice sunny day, 5,000 people lift off from their suburb homes, head to work downtown, land and park their personal flight craft .. all during the 8am and 9am rush hour?

I would not duplicate a transport network. I suggest that the mode of transport used on a nice sunny day be the same as used on a nasty, wet and windy day. Ride a bicycle to the train station. Use your “personal flight craft” as an expensive hobby in your free time, until it ceases to be a novelty.

When safer aircraft with more efficient low speed propellers or flapping wings become available the game will have changed.

 

[dragoneyes001]

any public personal flight would pretty much need to be a big old balloon type flyer. with enough impact resistance to protect objects the flyer is run into otherwise its a pipe dream to expect any government to approve general public use. saving the pilot would be secondary compared to protecting peoples houses buildings people in general and the clincher all government facilities and personnel. there is no more paranoid group about their own safety than politicians the amount of bunkers/no fly zones concrete barriers specifically to protect them should be evidence enough to see where they will go with legislation of personal flyers if they became mass producible and cheap enough for general use.

 

[hyteck9]

So that's it, huh guys? Why even try to build "the game changer" that becomes mass producible and cheap enough for general use? Let's just kill the idea before it even starts. Not really the feedback I was hoping for. Nothing exciting or new or great will ever happen if you only focus on the reasons NOT to do things. The next time someone asks me a question I'm just going to say, "Why bother having a discussion! The only thing that could possibly come from it is communication, information, understanding and progress! We can't have any of that progress stuff happening in this country! The government and politicians won't stand for it! Status quo! That is what our country was founded on! Yeah!" *mic drop*

 

[dragoneyes001]

I'm being serious when I said the personal flight machine has to meet those criteria that is not saying it can't be done but ignoring the most obvious criteria will only waste time on ideas that will be squashed as soon as they go for approval.

 

[timthereaper]

So that's it, huh guys? Why even try to build "the game changer" that becomes mass producible and cheap enough for general use? Let's just kill the idea before it even starts. Not really the feedback I was hoping for. Nothing exciting or new or great will ever happen if you only focus on the reasons NOT to do things. The next time someone asks me a question I'm just going to say, "Why bother having a discussion! The only thing that could possibly come from it is communication, information, understanding and progress! We can't have any of that progress stuff happening in this country! The government and politicians won't stand for it! Status quo! That is what our country was founded on! Yeah!" *mic drop*

It's not about killing the idea; it's about trying to figure out if solving the problem is worth it. I know you've got this notion that personal flight vehicles will be a "game changer", but it seems a lot of other people (myself included) can't see the potential value and throw up obstacles rather than solutions. Can you illustrate some points from your perspective about why/how PFVs will be clearly better/faster/cheaper/etc. than what we have now?

 

[dragoneyes001]

lets change the target audience for these flyers. like say owners of huge ranches where the use of the flyer is not so limited by public concerns what would be the criteria needed to make a flyer worth it to a rancher? things like easy to launch and land. carries what load? would it be good enough to haul a stray cow back to the herd without giving it heart failure...etc...

 

[berkeman]

Thread closed temporarily for Moderation...

 

[berkeman]

So that's it, huh guys? Why even try to build "the game changer" that becomes mass producible and cheap enough for general use? Let's just kill the idea before it even starts. Not really the feedback I was hoping for. Nothing exciting or new or great will ever happen if you only focus on the reasons NOT to do things. The next time someone asks me a question I'm just going to say, "Why bother having a discussion! The only thing that could possibly come from it is communication, information, understanding and progress! We can't have any of that progress stuff happening in this country! The government and politicians won't stand for it! Status quo! That is what our country was founded on! Yeah!" *mic drop*

Thread is re-opened for now. @hyteck9 -- Please do not chastise those that are trying to help you with your questions. Some things are practical, and some things are not. Our job as engineers is to weed out the things that won't work early, so we can focus on things that may have a chance of working.

 

[dragoneyes001]

the more i think about a ranch use the more I'm inclined towards a simple type of helicopter which doesn't need a few thousand hours of flying time to master.
also small enough to range alone but able to link with other units to become a large weight hauler.

 

[mheslep]

Power source: ... Electric will be better, but until you can make something more energy dense than the lithium ion battery

Electric fans/props and batteries work, the problem is range. I believe max range is ( Cbatt/g ) * battery mass fraction * efficiency * (L/D), where C is the battery capacity in joules per kg; L/D = lift/drag is best case 30 (global flyer); mass fraction maybe 70%. For the current best 1 MJ/kg batteries, range is then ~1600 km. That's short range compared to large commercial aircraft, but for a personal single seater I doubt many people want to travel that far in one hop. Ceiling would be interesting.

 

[HuskyNamedNala]

There are some pretty technical considerations and it comes down to the propulsion system. Unless you want to give a person a 20-30 foot wingspan you need to generate enough thrust such that you can obtain sufficient lift, while over coming drag (which won't be trivial since a person can be approximated as a rectangle), for an extended period of time, that is also lightweight... and safe.

The only thing I can think of is rocket propulsion to get the person to altitude, then a high efficiency propeller for cruise. Interestingly, there is a "jet pack" that uses pumped water at a high velocity to generate thrust. You are limited by the hose and head loss, but it is pretty neat. This makes sense too, as the density of air is just under 1000 times higher than air, and thrust generated by an accelerated column of fluid is approximated by
rho*delta(V^2 *A).From an aerodynamics standpoint I am a big fan of biplanes (even though they went out of style a hundred years ago I think with composites they can come back), which would maximize lifting surface area without occupying too much space. A good biplane design can obtain about 30% more lift with double the wing area. I think with the right stagger and a reflexed airfoil you could overcome stability issues too. MIT developed a human powered aircraft that used flapping with technology. It cruised about...1 foot above the ground with 1 human as a payload.

 

[Dale]

I want to talk about personal flight options. I have searched in, and external to, this forum and understand there are various types of options currently available. However I'm not sure they are truly practical to usher in a new era of personal flight.

Why personal flight? I cannot think of a good use case for mass personal flight. If you are talking "practical" then there has to be some practical use case.

For commuter transit an infrastructure based approach will be cheaper and safer. With the 15 minute flight time it seems unlikely to satisfy either business or leisure travel needs. For ranchers it is hard to see how you could beat a 4x4 truck. Etc.

Until you know what problem you are solving you can never tell if a solution is practical.

 

[timthereaper]

Why personal flight? I cannot think of a good use case for mass personal flight. If you are talking "practical" then there has to be some practical use case.

For commuter transit an infrastructure based approach will be cheaper and safer. With the 15 minute flight time it seems unlikely to satisfy either business or leisure travel needs. For ranchers it is hard to see how you could beat a 4x4 truck. Etc. Until you know what problem you are solving you can never tell if a solution is practical.

My views exactly. For people that would have a good use for a personal flight vehicle, they can buy a plane/gyrocopter.

 

[GTOM]

I also wondered about the option of flapping wings, whether it is more energy efficient (for low speed and altitude at least), or not?
Gliding is more energy efficient than constant thrust (compared to a jetpack), with flapping wings, lesser runway is needed.

Well i could sure accept such a thing for leisure at very least.

 

[HuskyNamedNala]

Flapping wings are only applicable to low Reynolds number applications. Check out the MIT PhD project published within the last 5 years.

 

[Dale]

Well i could sure accept such a thing for leisure at very least.

What would be the use case? Are you talking about traveling to a leisure destination or are you talking about a "joyride"?

If the former, then what destinations could it serve that are not already served. If the latter, then what are you looking for that hang gliding etc does not already provide.

 

[anorlunda]

Baluncore,
The loss of power issue I think is best handled with a parachute. They are simple, small, proven over time. No reason not to have one as a last resort.

The sad fact is that parachutes that land in trees or anything other than open ground often result in injury or death to the passengers or to people on the ground. Parachutes are worthwhile to carry, but they are no solution to safety. If you are flying lower than 1000 feet, a parachute may not have time to deploy. An ER nurse told me that the number one cause of injuries locally are paragliders that lose power over wooded areas.

As for "advanced controls" as a throw down trivial solution to real life problems, Airbus 320 comes to mind. All the kings horses and all the kings men may not be able to design advanced controls that will save Humpty Dumpty.

 

[Syed Ammar]

What I think at this point after going through all the post and its replies, is a solar-aircraft with fold-able body, with high storage power batteries. If carrying power with you is a hurdle, why not put up a solar station (in geostationary orbit and elsewhere, just suggesting) and use microwaves to beam it to your required machinery?
hyteck9,
The traffic, security and political problems ( Blah bla bla) will have to be handled later ( Politicians across countries never agree to anything good anyway :3 ) . What really matters here is the science involved behind personal flight.. And it is also a point to be noted that personal flight (until an extremely efficient power source is discovered) will be limited only to entrepreneurs and the "BIG SHOTS".

 

[Ryan_m_b]

What really matters here is the science involved behind personal flight

Actually I think Dalespam highlighted what really matters here: unless you can fully identify and characterise a problem you can't envision a sensible solution. This thread seems to be trying to merge two separate conversations poorly;

1) The interesting and perfectly legitimate discussion on how personal flight could be achieved through current science and technology

2) The discussion on how to overcome the impracticality (economic, legal, safety) of personal flight

I think it's pretty clear to most people that widespread personal flight is a non-starter due to a host of reasons related to point 2. That doesn't stop it being a fun exercise discussing how to do it and under what niche circumstances it might make sense but slotting the two together is putting the cart before the horse.

 

[nitsuj]

Hmmmm...Futurama seems a fairly accurate prediction of future travel. So for inter-city travel it will likely be tubes with a vacuum. Maintianing body position is important.

piloting personal flight devices must be so fun and exciting. And they all seem to have "fail safes" implicit in the design. Such as gliding ability or a parachute.

why no massive paracuhte for passenger jets, for those situations where it's clear a crash is going to happen. Surely there is a "frame" of sorts that the chute could attached to, same as the what ever the seats are attached to. Surely it's been toyed with, I wonder the issues with it.

 

[timthereaper]

I think it's pretty clear to most people that widespread personal flight is a non-starter due to a host of reasons related to point 2. That doesn't stop it being a fun exercise discussing how to do it and under what niche circumstances it might make sense but slotting the two together is putting the cart before the horse.

Agreed. It seemed the OP wanted more than to discuss current technologies that could have applications in personal flight. The problem is that to mature any promising ideas we have to look at the most practical use case scenario and base all our tradeoffs on that, and there is no accepted practical use case scenario. That means we keep bouncing between points 1 and 2.

 

[dragoneyes001]

if you look at the four propeller drones hobbyists fly around making one large enough to carry people while not making a military sized unit would be a possibility for this application. it could be electric. the controls would need to be self leveling for ease of flying it so tilting rotors to accelerate and slow flight with enclosed rotors for additional safety. the big issue is how to create a safe loss of power decent.

 

[GTOM]

Flapping wings are only applicable to low Reynolds number applications. Check out the MIT PhD project published within the last 5 years.

Cant it be solved with better components? Feathers are hard to mimic.

If the latter, then what are you looking for that hang gliding etc does not already provide.

That requires starting from a high place.

Otherwise, an energy efficient way to fly above traffic jams wouldn't be bad, if it can be solved. (We got a number of them in our country.)

 

[GTOM]

What would be the use case? Are you talking about traveling to a leisure destination or are you talking about a "joyride"?

If the former, then what destinations could it serve that are not already served. If the latter, then what are you looking for that hang gliding etc does not already provide.

I have to correct my last answer. So yes, there are multiple options, airplane and glide once you are up, start from a mountain, dragged by a fast land vehicle.
But IMHO, nothing as good as take off on my own, and theoretically, even able to land in our garden.
I wrote about the other application i can imagine in the previous post.

 

[meloettakawaii]

Here's my proposal:

Lets first understand and mimic what nature did because nature solves problem oh so well.

The goal is a bird form factor scaled to the size of a human.
The pilot will strap on an exoskeleton with collapsible wings just like the birds for space saving and wing controls.
The pilot will have full range of control over the wing's degrees of freedom similar to how birds can rotate, extend, bend, manipulate each of their wings independently.
The exoskeleton amplifies the pilot's actions therefore enabling vertical takeoff like birds, or with the assistance of a quick dash and a jump.
The exoskeleton plus the pilot will have a center of gravity precisely balanced so that in freefall, and movement of the wing / other body parts would change the flight trajectory.
Materials used to build this would be high strength to weight ratio such as titanium, carbon fiber, etc.
Actuation would be artificial muscles, (coiled nylon/fishing wire?, pneumatic?, etc.) must be lightweight
Power source at this point would high density batteries or if you have a better option that better with work to weight ratio.

what do you think?

lets not get into the non-technical issues, if this can be build today, the world would bend around making this commercially available.

 

[king_me]

Self driving cars will be implemented, the steering wheel will eventually be removed & algorithms to control this ‘network’ of vehicles will be finely tuned over an extensive time period.

This is how the air space will be controlled, by the program that controlled the cars but reconfigured to work in the air. That or Amazon, Google with their drone delivery service.

Whatever is built can not be driven by humans, at all…ever.

85% of the safety is now taken care of but needs a decade+ to take effect. The last 15% is the risk factor in the flying unit itself.

Flapping:
You could genetically modify a person to have wings and fly but hell…all you would do is eat & sleep to get the energy to flap. Could you train a bird that was big enough to carry a person? It would rather eat you and if you ever got on it the takeoff & landing would be extremely violent.

Fixed wing:
Buy a plane and go fly it. Gliders are n/a.Gyro:
It’s a small helicopterRocket:
Kaboom!Turbine anything:
Old technologiesParagliding:
Motor & a propeller on the back and all you need is a head wind. N/A…requires human inputDrones – battery powered:
You can scale it up all you want but I’m not getting on it.

But hey, we’re talking The Next Level…………….3D printing: (basically teleporting)

You need a scanner to record your body (destroying it in the process) then wirelessly sending the signal to the other booth… less than 15 minutes but hey, you’re flying right!? (can you get to the moon in 15 minutes as a signal?) Ultimate in personal flight! Can you say we’re not heading in that direction in regards to the printing? It’s the recording that we’ll have issues with.

Is teleporting too far off the subject? My brain can go off on a tangent sometimes.

 

[Baluncore]

Gyro:
It’s a small helicopter

No.

A helicopter has a powered rotor, air is driven down by the main rotor. A tail rotor counters the torque. Rotor blade angle is controlled by the pilot through a swashplate. The axis of the main rotor is fixed relative to the body. A helicopter leans forward to fly forward.

An autogyro has an unpowered rotor, air moves up through the rotor. The rotor is much like a glider. There is no control of blade attitude as that self-adjusts on a rocking bar. The body hangs from the rotor, the pilot controls the relative axis of the rotor and body. An autogyro is usually pushed along by a propeller. It leans backwards when flying forwards so air will move up through the gliding blades.

 

[king_me]

No.

A helicopter has a powered rotor, air is driven down by the main rotor. A tail rotor counters the torque. Rotor blade angle is controlled by the pilot through a swashplate. The axis of the main rotor is fixed relative to the body. A helicopter leans forward to fly forward.

An autogyro has an unpowered rotor, air moves up through the rotor. The rotor is much like a glider. There is no control of blade attitude as that self-adjusts on a rocking bar. The body hangs from the rotor, the pilot controls the relative axis of the rotor and body. An autogyro is usually pushed along by a propeller. It leans backwards when flying forwards so air will move up through the gliding blades.

Oh yeah that's right! How silly of me.