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Tiny little tourist blimp!

  1. Dec 27, 2004 #1
    Hi, since my maglev launch track for suborbital space tourism is too expensive to make, I decided to come back to earth and build a little one person blimp for ordinary eco-tourism!

    Great idea, isn't it? Can you imagine yourself on holiday in an exotic country, exploring lush rainforests, islands, deserts, savanna's, valleys or canyons? Yes you can. But the one thing you've always wanted to do is to explore these landscapes from the sky. Hiring a helicopter is too expensive, ballooning is noisy and you don't know where you'll end up, and using a small airplane limits the experience. So here we are: a tiny one person blimp, which moves slowly over the landscape. Perfect for eco-tourism, don't you think?

    Now since I'm extremely lazy and I don't know a lot about physics or engineering, I ask you to help me. Thanks in advance.

    What I want the blimp to be is:

    -silent >> so electrically powered (a battery array weighs a lot, but we're renting out for one hour trips); the batteries can be recharged by solar power, excellent for use in off grid communities (say, in the Kalahari desert)
    -fly at slow speeds, say maximum 30km/h >> what kind of a motor would I need?
    -easy to operate >> so I need some kind of fly by wire system which allows the tourist to fly freely, but which puts him back on track if he comes too close to rocks or trees, and so on
    -able to land and lift off anywhere >> so the thing needs a big airbladder of say 100m³, in order to control buyoancy.

    Is this a big design challenge? Or can it be done fairly easily?
    I really think there's a market for such one person blimps. Tourists are willing to try anything, as long as it looks fun and safe. And leisure flying is the only thing we're missing in general tourism (you have leisure boats, bikes, cars and kayaks, but no blimps).

    Thanks for your comments and for helping me designing it!
     
  2. jcsd
  3. Dec 27, 2004 #2

    cronxeh

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    Ahahahhahahahhahahha
     
  4. Dec 27, 2004 #3
    I don't see what's so funny about making small blimps for lame tourists.
     
  5. Dec 27, 2004 #4
    And what's more, cronxeh, I suggest you stick to making your LPG powered airplane, ok?
     
  6. Dec 27, 2004 #5

    cronxeh

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    OK!!


    ohhh.. too funny.
     
  7. Jan 3, 2005 #6
    Sure, the electrical motor would be fairly silent, but the prop won't! Better stick with an AVGAS-driven carbureted recip engine, which would be cheapest to both maintain and operate.

    Fair enough. Then the prop can be fixed pitch without a major performace loss, saving a whole lot of maintenance.

    This is the most sensible this far, although the FAA or CAA will break your dream quite quickly. Getting a virtually pilot-less passenger-carrying system certified probably isn't going to happen in a thousand years. I know, riding a bike is probably more dangerous, but the bureaucracy can't be overrun that easily.

    If you've been scuba diving you know buyancy control is hard enough down there, without a huge balloon being in the way. And without a mooring tower the blimp would probably be very suspectible to gusty conditions. I'm not saying it's impossible, though.

    I'd say leave blimps to the advertising busyness. I agree, it sounds tempting at first, but it's far from feasable.
     
  8. Jan 3, 2005 #7
    Even more issues:
    Picture me humming along in my little Cessna, when suddenly - out of nowere a blimp with a lame tourist not knowing jack about air traffic procedures suddenly shows up out of nowhere. I know I'm the one to yield, but still, it could pose some dangerous situations. Either every little aircraft - including your blimp would have to be outfitted with TCAS and mode-s transponders, which costs fortunes, or the blimp would have some kind of AI and voice synthesizing system publishing intentions on the right frequency using data from a GPS, as well as speech recognition (that WILL fail) to receive clearances from air traffic control (ATC), and again, CAA/FAA will not only say no, but they will refuse to listen to you for all eternety for making such a suggestion.
    Having this kind of aircraft around is a danger to other air traffic, as well as the blimp's passenger.

    Edit: More ranting!
    Parsing even the strict ATC phraseology is a tough job for a computer. Get someone to read this to you in 20 seconds while trying to write down all the data:
    "Lima foxtrott yankee, you are cleared inbound two thousand feet and below for a left downwind runway three zero, wind one fife at niner, QNH 1004 hectopascals, squawk 1231" (this is close to a real message I got on a busy day, and such messages comes in all sorts of sequences and variations)
     
    Last edited: Jan 3, 2005
  9. Jan 3, 2005 #8
    Hey thanks for your input, but the idea is more to use this blimp in very well circumscribed environments, basically tourist spots (deserts, grand canyons, rainforests, small islands etc...). These places see no other airtraffic, so that won't be a problem. Moreover, the blimp would have a very low ceiling of only a few hundred feet.

    Still, I'm not sure it would be feasible to make such a blimp. The market for it is there, though.
     
  10. Jan 3, 2005 #9

    FredGarvin

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    It's nice to think of the what-ifs. Especially when dealing with flying concepts. My company has worked with NASA for quite some time as part of their GAP program. One of it's end dreams is to have more of the general populus being able to fly low cost aircraft. It is horribly apparent to me that this will never happen. Too many people have problems with 2 dimensions, let alone 3 when it comes to controling a vehicle. It doesn't matter how idiot proof one makes it, there will people that will screw up.

    I highly doubt that the market you mention is big enough to support the development cost of this type of aircraft. The control system alone would put you out of business.
     
  11. Jan 4, 2005 #10
    They will see enough traffic to be in the way. Where I live you can do whatever you like below 2500 feet, except landing without permission of land owner, even in hyper-restricted Norway. And people do fly from time to time.

    And if you overcome the economical problems there would be one final issue: visual pollution. I hate everything from streetlights preventing me from seeing the stars to billboards cluttering my view. I am thankful that we don't have any commercial blimps here in Norway.
     
  12. Jan 4, 2005 #11
    Thanks for your input.

    I do understand your concerns, but let me add this: the blimp would really fall in the category of leisure things like sports-kiting, parawings, ultra-lights and so on.

    Gschjetne, you are from Norway. If I am correct, there are a lot of cruises in the fjords, aren't there? Well, this would be no different, only much more small scale.

    The idea is not to sell this blimp to individuals, but to tourist operators. Say you are visiting the desert in Senegal (very popular amongst tourists, and there are no airplanes around, literally, none). You basically have the option of hiring a 4WD or a camel. It wouldn't be surprised if tourists would take a ride on a blimp if they were offered the possibility.

    The learning process of steering the blimp would be part of the fun. And it must be quite easy to learn (judging from reports of those people who flew the "White Dwarf").

    I don't see the problem of visual pollution. We're talking a few blimps in popular tourist spots.

    For the White Dwarf, with pictures, see this link:

    http://home.teleport.com/~reedg/whitedwarf.html
     
  13. Jan 4, 2005 #12
    One more thing about the fly by wire stuff:

    -this could well be conceived as being a very "localized", static system, not a universal fly by wire thing
    -a scanning system would simply map out the terrain around the tourist spot (say in a radius of about 50miles around the spot), and this detailed input would be used to steer the thing on autopilot (maintaining broad and simple parametres about wind speed, the speed of the blimp, etc... )

    It must be quite possible to use existing software and techniques to create this.

    For more pictures of the fantastic White Dwarf, and an amateur collection of info on small (one person, fuel cell powered and human powered blimps) see this link:

    -http://www.eng.qmw.ac.uk/dorrington.shtml
    -http://www.firstpr.com.au/blimp/
     
  14. Jan 4, 2005 #13
    I'm afraid I'd have to agree with 'FredGarvin' and 'gschjetne' on this. Leasing out small blimps would lead to a lot of 'learning' accidents (and possibly, lawsuits). Aircraft, of any type, are simply not as safe or easy to operate as are surface vehicles (besides, most of us already have some driving experience). For blimps, the slower speed makes them easier to handle in one way, and more difficult in another. They become quite unstable in any type of wind or air currents, and near surface impediments, such as power lines, towers, etc. making these dangerous. You'd have to have an experienced, licenced operator to ever be able to get insurance.

    Also, a small, one-person craft doesn't make for a good money investment. You'd need to be able to carry at least four people, and up to twenty would probably be better - - and if you are going this route, you should probably consider a rigid airship. And - - I hear the Germans are already making one of these - - which is used for local cruises in that part of Europe.

    KM
     
  15. Jan 5, 2005 #14
    Ah, I live on the eastern part, so I don't see much of the fjords, except the Oslo fjord, which is so wide sea traffic doesn't bother me. But I forgot to rant about all the cruise ships scraping their paint off in narrow fjords...

    Anyway, for sightseeing, I'd say the best option is still light airplanes. They are small and modest in blocking the view, very safe, not too noisy if the pilot doesn't "hotrod" the plane, and probably most economic.

    BTW, something I've been wondering about regarding blimps: How significant is drag in blimps? Most people I've been talking to say it's not a problem, because it's "aerodynamically" shaped (hate that term, it doesn't say anything about how streamlined it is, just that it's related to the dynamics of air), but a sufficiently large blimp with some speed would have a significant amount of air to move around...
     
  16. Jan 6, 2005 #15
    Blimp

    I have looked quite extensively into this subject and may be able to help. I have an engineering background, worked in the industry, and also have two pilot's licenses. This is a bit of a read, and theres some technical jargon there, but everything you asked I think I answered.

    Sad to say, something like a one person blimp present significant engineering hurdles. On the plus side though, contrary to what someone else said, (at least in Canada) you DON'T need transpoders, GPS, or high tech electrical doo-dads depending on where you're operating (in some airspace yes, but others no, so stick to the "others") Furthur though, it would be a good idea nonetheless to familiarize yourself with air law, simply because when you're hundreds of feet up, there isn't a lot of room for error. And I can only agree with the thoughts that its a lawsuit in the making. In industry they say "make something completely idiot proof and the world willd design a better idiot". I was looking at this for personal uses, unlease air travel to average joe sixpack who has no training is only asking for trouble.

    Next, engineering challenges.

    1) 1 m^3 of helium can lift about 2 lbs. 100 m^3 (your spec) can lift ~200 lbs TOTAL. Weight of pilot, ship, motors, seat, control systems, everything.

    Assume you have a sphereical bladder. (oversimplification but making a point), 20 m wide. Its volume is 1333 m^3 (lifts 2666 lbs), and surface area (covered by frame and skin thus weight) is 1250 m^2. Take the volume down by 50%. Now it can lift 1333 lbs, its 17.8m wide and has a surface area of 800 m^2.

    Whats happened is you've descresed lift by 50%, but only decreased mass by about 33%. As you can see, blimps like to be big because a large frame holds much more gas for its size compared to a small one.

    Here you have a considerable design challenge. A lightweight frame must be designed and fabricated, and a lightweight, rigid, helium tight covering applied. Experienced engineering consultants charge on the magnitude of $100/hr. To DESIGN. Then you need it constructed from costly materials.

    2) Wind and Drag. Think of a 30km/h wind on a tiny surface like yourself. Its a noticable force. Now multiply that up to the large frontal area of an airship (hence the tube desing to lessen frontal area). What you get is a decent sized force that requires a decent sized engine to maintian. In order to not be at the whim of the wind, you need to be able to do 30-50 km to override it, thus big engine, lots of fuel, and lots of new weight.

    As for a specific number, that someone asked,

    Drag Force = 1/2 * Speed^2 * air density * frontal area * Drag coefficient.

    Drag coeffients are fairly small for airships, about 0.3 for a car - you could probably get down to about .1 or .05 if it was well designed for the aerodynamic bladder, but then add on for control surfaces, pilot, cab, etc, so we'll say .1 and a front area of 10 m^2

    Thus 1/2 * (8.3 m/s)^2 * 1.2 kg/m^3 * 10 m^2 * .1 = 413 N or about a 100 lb horizontal force. Not a huge force, but you'd need a ballpark 5-10 HP engine or so. Maybe more to make up for inefficiencies. The Hindenberg comparably at 800 feet and 135 km/hr had 4 1200 HP engines. Even a one man blinp would likely be 30-40 feet long so you're not in a completely different ballpark.

    3) The problem.

    You design your one man frame, motor, control system, and around your size, and find out you don't have enough lift. Thus you need to increase bladder size. This in turn increases weight of frame, increases the effect of drag, and increases size of needed engine. The good news is that you increase the amount of lifting you can do, A LOT quicker than you'll be increasing weight. Which takes us back to the first point, Blimps, especially full service ones with GPS and engines and batteries, need to be big.
     
  17. Jan 6, 2005 #16
    Thanks a lot for your input, seadog

    Like most contemporary airships, this one would be of the non-rigid kind though.

    I don't see the problem, there are plenty of very good 5-15 HP electric motors out there, which weigh only a few kilos.

    To my own calculations, the blimp we're talking about would be in the FAI category "BA-01" (non-rigid gas airships: 400m³ and less).

    The White Dwarf was about 180m³. I need to add an airbladderto control buoyancy (which the dwarf did not have), and extra volume to include the battery array (approximately 50kgs).

    In total, 350m³ should be more than sufficient, I think.
     
  18. Apr 18, 2010 #17
    We are building an UltraLight one person dirigible with electric power at
    smallblimps.lefora.com
    UR welcome to look and join and fly.

    it will be affordable and cost maybe a grand to make.
    Builders wanted, not chatterboxes ;-]
    The Nav see allenmeece.info
     
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