Roadable Aircraft DESIGN

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by WonderousMountain, Jan 23, 2012.

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  1. Jun 3, 2013 #1161

    captarmour

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    holden, maybe we should all get together with you and build a prototype
     
  2. Jun 3, 2013 #1162

    jedi

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  3. Jun 3, 2013 #1163

    Southron

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    Don't mean to be a "wet blanket" but keep in mind that during the Middle Ages, Alchemists spent a lot of time and energy trying to figure out how to turn lead into gold. The roadable airplane has been around since World War II.

    Why a "Roadable Airplane?" If someone designs a decent aircraft that lands and takes off VERTICALLY in driveways and parking lots of shopping centers, and with less noise than a regular automobile-that person will have a winner.

    In other words, WHY would one want to ride on a road when they could fly instead???
     
  4. Jun 3, 2013 #1164

    captarmour

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    i think all of us would rather fly...what about cost and complexity though?

    this aircraft weighs 425 lbs and with a 74 inch prop pushing 500 lbs of thrust takes about 30 feet run to take off! with a 92 inch prop it can push 600 lbs of thrust. the largest prop with taller gear is 102 inch. with a bit of redesigning, like small canards in the propwash for thrust vectoring, larger controls and a more nose up stance, she could be made to take off vertically.

    http://www.youtube.com/watch?v=wGUR2s3wwr0
     
  5. Jun 3, 2013 #1165

    Holden

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    ron,

    VTOL is 10-100 times more difficult and it has a "dead man zone" among many more "problems" to contend with. Aircar has covered this many times....air blasts, dust, noise, risks of engine failure, can't get the last mile from where you land...on and on. VTOL is NOT the answer and will never be. It requires very high power and low speed thrust which no engine does well. Cruise and vertical are at the extremes.

    By accelerating to 35-45 mph with wheel power and simple engines you can get something a average guy could learn to fly, but who can fly a helicopter? Few and far between. Flying backwards is a lot harder than just forward like a car.

    What happens when the weather is bad?

    What if you can use the pod without the wing?

    Insurance is the same if you use it flying or driving. Pull the wing off and you have a car that can be used 7 days a week that can get 100 mpg.

    Weight, complexity, water, snow...useful vs nearly useless. You cannot land a VTOL just anywhere any more than you can a helicopter.

    What if I have an engine failure...just land and drive.

    Want more reasons?

    Holden
     
  6. Jun 3, 2013 #1166

    Holden

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    Captarmour,

    I am working on designing it. Why build until the concept truly is worthy of the massive effort. I am close, but not there yet. I have to have a really compelling reason to set out on this 5 year project. The Sea-Era taught me a lot and I don't want to make the same mistakes, nor do I want to have to pull the plug on the project after I find a major flaw. I surely would not want to have people helping and then find a flaw, so...haste makes waste.

    Thanks for the comment. This airplane would be so much fun in Dominica and that area!

    Holden
     
  7. Jun 3, 2013 #1167

    Aircar

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    Catching up - N15Ks - for some reason I couldn't post on your thread --the 'flyable motorcycle" which acheives much of the airport to home access part of the roadable aircraft EXCEPT for the mind numbingly stupid traeatment you got at the hands of the EAA and FAA etc --presumably driven by the post 9/11 security clampdown (why wouldn't you just FLY a bomb in if you wanted to do some harm ?) The tightening of security into airports happenned here actually a lot earlier but that is another story --the trick is to not need an airport and that leaves ATOL or VTOL with many insolubles on the VTOL side .

    The greatest lesson from the 2200 plus previous unsuccessful attempts at a 'breakthrough' flying car (none intended to be one offs or part of the aeronautical fringe 'freak show' I would bet --apart from the couple of virtual mock ups like the monster garage one week one or that 'push over the edge' one on the video just posted ) -is that SOMETHING very fundamental has to be changed very significantly to avoid more of the same.

    I have given you my analysis and outlined the solution --including some historical antecedents (eg the Brodie system) -the space we need to take off and 'land' is right in front of your eyes -OVER the roadway! The space over roads is completely wasted territory and does not interfere with anyone else's enjoyment or use of anything --with a cable array between you and the traffic beneath it is also the safest place to be in event of a mishap . Anyway I am just repeating myself yet again - earlier threads should be looked at first ( a REAL jedi would have felt the force and not needed to ask ..)

    Previously also I tried to differentiate between a flying car (type 1) and a flying car (or other analog road vehicle) type 2 --the type I is able to go anywhere a normal car can (including inner cities and tight parking areas 'laneways etc ) and be available in the same sort of quantities as normal cars and for similar prices =--the skill level to use has to also be comparable (I defined this as "accessability' in that it meant the vehicle wasn't out of reach either literally or financialy or due to extreme skill etc -cars are accesable ) a type 2 includes all others but mostly too big,too expensive,too hard to operate, too inconvenient (eg manual slow rigging) etc etc --that is to say ALL prior art. (a tautology I know because you won't find any type 1s lying around or to buy.

    Airports are orders of magnitude too rare and costly (in communnitty terms if nothing else) to EVER permit 'type 1" operation or ownership so saying you can design for airports "to begin" is to design into a dead end --of course it is easier but then it is always easier to fail.

    What is a level of 'success' to be acheived by a flying car ? --lets' look at what is called "failure' in the car design field . Top gear pick on the lowly Morris (leyland) Marina as their 'dunce' among cars --they drop grand pianos on them and the Marina is ridiculed in EVERY 'worst cars of all time" book -- so how bad was it as a car ? In this I can speak with some authority since i have owned FOUR of them over a ten year plusperiod and probably suffered every significant fault in that time -- I never paid more than $250 for one and bought one for $65 (and drove it home w sitting on a can where the front seat used to be with no headlights or indicators across Melbourne...... I actually grew quite fond of the old Marina ,it WAS styled by Bertone after all.

    Anyway they ONLY built 800,000 of them ,oh and the follow up ITAL Punto that used the same body tooling etc which built another 126,000 --that's not far short of ONE MILLION of these 'lemons' (google it ) --probably not that far from the TOTAL of ALL flying machines ever .

    Makuti in India push out a new car every thirteen seconds (Top gear article ) Over 800 million cars on the road today - billions have been made.

    What is wrong with the airplane that is doesn't even get to the rounding errors in comparison to car production.? Might stand some thought before 'making haste'

    Of course a flying car/recumbent /etc COULD use an airport if nothing else was available --and would be demonstrated from them at first just like barnstormers flew out of harvested fields before mega airports existed --but the revers is NOT true ;without special attention in design a conventional or airport dependent airplane CANNOT use an ATOL system --it is locked into a dying and rare infrastructure.

    the choice of what to design is yours (that is what being a designer means ) - I am the 'odd man out' in proposing ATOL but then again the success rate of "all the rest' hasn't been impressive.
     
  8. Jun 3, 2013 #1168

    Holden

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    Aircar,

    Thanks for the post. I enjoy your post with all the detail and history...

    I agree ATOL type system is needed in dense cities and it would be fun to develop. But it takes money and permission, both of which a few guys like us don't have in sufficient quantities...like spitting into the ocean. Yes, design so the roadable can use it, but that would require more info on what is required to interface with ATOL. Letting me know what is needed would help me make it work with ATOL...

    The reality is that if a roadable can be made in 100,000 units/year, ATOL will follow, if needed. First things first. If the roadable requires government to act, then it won't work.

    99% of the land does not need ATOL.

    There is a way to make a roadable and a "skytran" pod concept work together to get the craft into the inner city. A pod that can run on an overhead hanging track can have wings added to make it fly if designed so. If the pod had wheels on the bottom it could go on the ground like any electric car, and get to the last mile destination from the track. If it had a hook with powered roller blade wheels (like Rutan wants for his ski-gull, but with a high voltage electric motor driven wheels and a suspension airm) it would be able to hang down from the track and receive power from the track. The roadable then could have a hook with roller blades and hang from the track with its wing still attached and ride the track into town and land out. No more traffic jams.

    ATOL cannot accomplish both of these transit goals. Clearly, ATOL would be a low cost specific solution that could interface for roadables, but it could not appeal to none flying folk. Having both would be the real solution because the last mile kills all viability to any system. Hauling groceries 1 mile gets old real fast.

    That said, without several hundred thousand roadables, what government or private venture would invest in ATOL? Google gave $25 million for ICON, which is dead on arrival, but would they give to an ATOL? There is money for roadable IF IT WORKS, but for ATOL? Not until the roadable EXIST FIRST.

    What will work is the question...???

    Which is to ask about the costs. Insurance IS the main issue as well as parking. Having two vehicles requires people to have two insurance policies. Clearly insurance should be on the person and not the car, but how can I change insurance companies who make lots of profit by insuring the car and not the person.

    If a car is smaller than a garage parking stall can I park another car there? No, unless it is 1/2 the size in length. Is that practical with aerodynamics? NO... Which then says, why not use the space to make the roadable useful for many applications that eliminate need for other toys.

    How many people buy a 2 passenger car? Very Few. Why? Insurance, parking space, depreciation, taxes, and hassle. People want ONE vehicle that will work for their lifestyle...one for her and one for him. Most don't want a pickup or SUV if they did not need it to pull the boat or camper. They buy the SUV because it is cheaper to pay the gasoline bill than to hassle with two vehicles, two inspections, two insurance policies, two garage spaces, and two depreciation losses. One car is a passenger car and the other is a double use vehicle called an SUV which saves one parking space. It is cheaper to drive the SUV...

    Should it be a minimal machine? NO! It should be about 16-18 ft long and 6-8 ft wide (6 on the pod and up to 8 with wing, but better just 6, as you stated) and no more than 7-8 ft tall so that it can fit in the garage. (Use the space or it fills with junk anyway, right?) The wing should store in the attic when not needed so that the pod can park under the wing/engine set. It should go in water so the owner does not need a boat. It should be able to go on snow so that it can handle bad weather and go to Alaska (what use is it if it cannot explore Alaska...my personal goal). The airplane should allow people to sleep in it (camp) so that a new type of camping can be invented (sky camping?) so that they are not needing that SUV. The family takes two airplanes and it is much safer than one. Kids sleep in one and the adults in the other. The small kids sleep on the wing away from bears...

    Solution: have two roadables (his and her's) and the family goes in two airplanes when needed and gets rid of the minivan, SUV, boat and, yes, camper. I have 6 kids so I need two 4 place airplanes, not one fat 8 passenger airplane that is a scale up (how?) from a four. The wife can go to work in her pod and the husband can go in his pod with or without the wing. Pink and blue colors... This is the right size of things...

    That leaves us with the approach Jedi and I have listed out. What can you add to it? What are we missing from your historical perspective of 2200 failures?

    Holden
     
    Last edited: Jun 3, 2013
  9. Jun 3, 2013 #1169

    Holden

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    Jedi,

    add in

    #11 boating
    #12 snowing
    #13 camping for two
    #14 replaces need for SUV to pull boat or snow toys


    Holden
     
  10. Jun 3, 2013 #1170

    N15KS

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    Avweb reported on the Maverick crash. There was onboard video footage of the whole thing.

     
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  11. Jun 4, 2013 #1171

    Holden

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    N15KS,

    Not sure my wife would be much interested in such a craft. The labor just to set the wing up would eliminate 99% of the air commuters. Would be lots of fund getting to flying mode in snow...if at all possible.

    Why fly when you can drive faster? I can see if you are a missionary in the jungle...nah...my church would not allow members to get into it as boys scouts let alone missionaries. Worst than a model A without a starter. It is a guy thing.

    I think we can count this among the 2200 that Aircar mentions.

    Holden
     
  12. Jun 4, 2013 #1172

    Aircar

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    I had hoped that John Brown would have published his bloody book three years ago when first promised -go to CarPlane GMBH and get onto him to do it eventually . (i just scanned the latest American Flying with the lead story about Gustav Whitehead flying "first" and about John Brown's pet hobby of "Proving' that the Wrights were scammers and blackmailed the Smithsonian into rejecting Whitehead (Weisskopf's) claims -- it is a sad fact that Orville DID pressure the Smithsonian (only after they had championed their former director Samuel Pierpont Langley ...) and furthmore that Orville shamefully libelled and tried to discredit John Montgomery who had flown full scale man carrying aircraft -dropped from a hot air ballooon at 4000 ft decades before the Wright's ground skimming 1903 flight into strong wind downhill and at sea level. However the wright's general design was more influential in the history of flight than either Weiskopf or Montgomery (and even Percy pilcher whose 1899 design powered aircraft was successfully flown later in a BBC documentary )

    The travails of the flying car parallel those of the flying machine and we are still in the 'pioneering' years of the flying car --just flying is not enough to be deemed a success --the market will decide that in time .

    Right now I am in a fight to at least defend the POSSIBILITY of flying cars being used in Melbourne in what is left of my lifetime --the latest threat is a massive proposed underground road tunnel that will likely also claim a monopoly on ANY citywide transport system to protect it's toll revenue - as happenned in 1997 with an earlier tollway scam that cost over $7 billion to the govt revenue in 'concessions' --ONLY by showing the PUBLIC interest and overwhelming BENEFIT when a mature and not artificially constricted (by regulation or airport need etc) system is allowed. We need the model T of the air to do this.

    John brown is at gustave-whitehead.com according to flying -going there now.

    (note also -the weiskopf machine was definitely also a roadable -having wheel drive (something I pointed out to john some years ago and also supplied stuff from my files on this and the also wheel powered 'roadable' Richard Pearce (NZ) aircraft which is also claimed to have flown before the Wrights -under power. The claim to the FIRST flown ROADABLE aircraft is still contentious but no follow on influence to later designs ocurred.
     
  13. Jun 4, 2013 #1173

    Holden

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    Aircar,

    I wonder how many people, if they knew the Wright brothers, would have helped them? I think few would have helped until the fame of the project was secured. If people think they can be part of history, they jump in and work hard. The Voyager is an example, and so is the Wright flyer replica (USU Wright Flyer) http://www.youtube.com/watch?v=Ckg_oMeS00U.

    The trick is then getting people to think they will be part of history. Yes? Is that what you are suggesting, Aircar?

    If we are "still in the 'pioneering' years of the flying car" as you said, how can a designer get that feeling of history when it does not matter to him (me)? Synergy seems to have gotten lots of people to join in and in the background is this sense of history for something historical. I don't see the Synergy as historical, just another go fast project.

    The reality of history is there were many Wright brother types attempting to achieve flight. The Wrights had each other to bounce ideas off. This chemistry is needed. I had that with Paul Weston in the Sea-Era project as long as it was within Paul's boundary of what to build. When I suggested recently to work together on a roadable, he did not have interest.

    The trick is finding the right people with the right goals. That is hard. The Wright brothers had each other. My brother could care less. My sons are 10 and 12 and not of much help.

    What is your experience over your life, Aircar? Have you been able to get that fire feeling in your project? It is almost like one has to be a cult leader or something.

    My view is this. Here is a cool airplane that is useful. It can drive on the road, parks in garage, lands on water, snow, and short field at 50 ft. Take the wing off and it gets 100 mpg. Can bank like a motorcycle or fly it on the ground 2D. Fish out the front, banks on the water, no need for a boat. Camp in it, sleep on the lake, go to Alaska. Sound fun? Want to help? Answer: Sure $50/hr or half your company even though I don't have one thing to add to the project...

    Comments?

    Holden
     
    Last edited: Jun 4, 2013
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  14. Jun 4, 2013 #1174

    N15KS

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    Most people want to define the problem as narrowly as possible. I would suggest that we first define the problem as broadly as possible. Here is my stab at the goal of roadable aircraft.

    The goal is to transport occupants to their final destination, while providing a value proposition that is superior to competing modes of transportation.

    Here are some further thoughts about this goal:

    A) This goal of roadable aircraft is the same as any other form of transportation. This goal recognizes that cars, trains and buses all compete for our transportation needs.

    B) Too often, this forum is focused on ways to make roadable aircraft "work." However, all previous "working" examples failed commercially. The failure of roadable aircraft is really a failure to achieve a competitive value proposition. We need to keep this in mind if we are to avoid making additional "working" failures.

    C) We all have different preferences for how roadable aircraft should be. We love to argue about the maximum vehicle dimensions, speed, number of wheels, etc. However, the general requirement to travel from "A" to "B" does not specifically require any of these features. In fact, it does necessarily require flying!

    D) How well this goal has been met, may be measured in units sold, and dollars made.
     
  15. Jun 4, 2013 #1175

    Holden

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    N15KS,

    Yes, I agree in theory, but in practice we all want to FLY on HBA, NOT drive. We are biased and have hidden agendas.

    I value the freedom of flight and find a road a linear prison. The value proposition (MBA term) has the word value as the modifier, and a proposition is what you give to "ladies" of ill repute.

    This is why my value proposition includes other value or niche propositions, such as water (boating, but more fun), snowing (with an air twist), and extreme STOL for back country adventure to remote lakes. It is a total off road machine, whereas a Cirrus is a sterile glass cockpit that interfaces to the FAA...just a little more fun than the IRS.

    Your "C" point is a show stopper. If it does not fly, why bother. I can think of several better ways to get from A to B on ground based systems that would be 1 cent/mile. The journey is the value proposition, not just A to B. This is what kills me about airliners. You spend 20 cent/mile on a jet at 40,000 ft sitting next to someone you don't want to be next to and miss the journey. Even the cockpit view is boring. Your point is like saying life is about how to get from birth to death. No, life is about what happens between A and B. A and B is the excuse to do life. Yes?

    Units sold and dollars made. This is true IF the value can be monetized. Most values cannot. People buy Mercedes for the status, not A to B.

    I see your point and it is the perfect MBA answer. I did the MBA thing to see why MBA managers were disconnected and drove me crazy. I am doing this airplane to see the world in a way I could not even if I had millions to spend. It is a song that must be written and sung to feel alive. I am on a mission, not just out to earn some money.

    Holden
     
  16. Jun 4, 2013 #1176

    jedi

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    Reference prior post #1169:

    OK, add limited all surface terrain capability to the list to include snow and water. Not sure what to do about camping; sleep inside or just have suitable baggage capacity.

    Any comments on #8 Are airplanes safe enough? Is motorcycle/bicycle level of safety adequate?
     
  17. Jun 4, 2013 #1177

    henryk

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    Ultra-Thin Super Insulation with Aerogel

    =YES,iff AEROGEL insulation is installed...

    =YES,iff KINETIC ENERGY ABSORBERS \INERTER\ are installed.
     
  18. Jun 4, 2013 #1178

    Holden

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    By camping I mean basically allowing two people to "bunk bed" one over the other (needs enough vertical separation...navy spec?) or opposite ends (one head to the nose of cabin and one to tail...long cabin) or something like that. The idea is to allow someone to pull over to the side of the sky highway, take a snooze and then continue. A lake becomes a great place to snooze for an hours so that you don't fall asleep while flying.

    A typical car fails in this regard because resting in a car is not comfortable. In a Cessna, for example, it is hard to make into a place to sleep. When it rains, what do you do? Take a snooze, wait it out, then go. This is not a must have, just something that is better than a car and important to pilot fatigue and use. when you have sleeping room you also have cargo ability.

    I also want to be able to take drywall in the airplane so you can build a remote cabin, but that would be a little much to "require" it as some must have.

    Airplane safety is motorcycle risk unless you can figure out a way to get 4 times better crash protection than a car has.

    The mass ratio is the issue. As I stated on other posts, a 35 mph crash between a 1000 lb roadable and a 4000 lb car results in a 62 mph crash (change in V) for the roadable and an 8 mph crash for the car. Clearly as the mass ratio gets past 1.5-2, the low weight roadable needs 3-4 times the crash protection that a 35 mph barrier would prove.

    Terrafugian missed this point and uses airbags that are only effective below 17-20 mph against a smart car. In other words, it is a waste of money. Instead of being 3-4 times dead, the airbags makes you only 2-3 times dead. Still dead either way, just a little less messy. The structural strategy of Terrafugia does not even being to meet the needs (4x more stroke than what a 35 mph barrier requires) due to the low mass of the Terrafugia against vehicles that are up to 5-50 times heavier.

    There needs to be an exemption for roadables under some amount, say <1600-2000 lbs or so. This way they can have 4 wheels and not have to play the motorcycle game. Until the law can be changed (good luck), the motorcycle rule is the only valid approach. Doing what Terrafugia is doing is a waste.

    Holden
     
    Last edited: Jun 4, 2013
  19. Jun 4, 2013 #1179

    henryk

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  20. Jun 4, 2013 #1180

    captarmour

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