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Future of aviation

  1. Jan 6, 2015 #1
    hello!

    I recently flew from Athens to London, with regular flight.

    I noticed that a significant part of the whole travel time is taken by the take off and landing.

    Why don't we develop a system, similar to helicopters, in order to achieve the fastest take off and landing?

    Also, I wonder why the plane couldn't just fly faster after taking off and before landing. Can't the human sustain such accelerations and velocities? We don't have the technology to fly that fast? What is the problem exactly?

    I strongly believe that with current technology it would be possible to diminish the flight duration to a fraction of its current amount.

    We already have airoplanes that drive much faster. Also, human body can sustain faster velocities and accelerations I believe. Current accelerations in a regular airoplane are not even noticeable!

    Any thoughts?

    Thanks!
     
  2. jcsd
  3. Jan 6, 2015 #2

    Doug Huffman

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    Nuisance abatement, costs and safety are preeminent considerations.
     
  4. Jan 6, 2015 #3
    I don't see how we cannot meet these with new systems, vertical landing and take off
    as for costs, they earn millions!
    I don't see why they cannot be safe, in fact, normal landing and take off seem more risky to me!
     
  5. Jan 6, 2015 #4

    Ryan_m_b

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    I don't see why VTOL would make takeoff and landing any faster, after all you'll still have to get up to cruising speed. As for faster journeys you might want to take a look into Concorde, specifically how uncompetitive it was compared to regular business class, private jets and growing use of telecoms in business.
     
  6. Jan 6, 2015 #5
    The real problem is efficiency. Most planes are designed to cruise at a certain speed and going much faster/slower than that affects the performance of the aircraft. It's not a speed limitation; it's a fuel conservation thing.

    As far as VTOL, there's a lot of research in it, but it's not reliable yet.
     
  7. Jan 6, 2015 #6

    Borg

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    So in your world, people with heart conditions wouldn't be allowed to fly? o_O
     
  8. Jan 6, 2015 #7

    SteamKing

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    Most of the delays encountered at airports are due to the number of flights landing or taking off at any given time. It's not that the planes are that slow landing or taking off, but you've got a pretty complicated 3-D problem trying to manage the flights on the ground and in the air. There are only so many runways and so much airspace which can be safely occupied at any one time.
     
  9. Jan 6, 2015 #8
    in the world YOU are living, people with heart conditions aren't allowed to fly, too
     
  10. Jan 6, 2015 #9

    phinds

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    I find that unlikely. Can you cite a solid reference for that information or is it just your opinion?
     
  11. Jan 6, 2015 #10
  12. Jan 6, 2015 #11

    phinds

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    OK, thanks. I was aware of guidelines about not flying if you have had heart surgery or a heart attack within a few weeks but there seem to be even more restriction that I was not aware of.
     
  13. Jan 6, 2015 #12

    berkeman

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    Those contraindications are generally because of the low O2sat levels involved in flying at altitude. I'm thinking that phinds was referring more to the g-levels that you were implying in shortening the duration of flights...
     
  14. Jan 6, 2015 #13

    phinds

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    No, to be fair, I just wasn't aware of the restrictions. I was told after open heart surgery that I shouldn't fly for the next several weeks (and check w/ the cardiologist in any case) but I was not aware that airlines had regulations about it, so I really was wrong. I thought it was just medical guidelines. I guess the airlines don't want anyone dying on their planes :smile:
     
  15. Jan 6, 2015 #14

    berkeman

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  16. Jan 6, 2015 #15
    yeah, I was imagining a combination of VTOL and horizontal movement
    to the point it becomes hardly noticeable (0.5g?)

    now, we get 1g during the take off and after that, we don't feel any acceleration
    why not the plane accelerate during the half of its travel? and deccelerating for the rest half
     
  17. Jan 6, 2015 #16

    berkeman

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    Because as has been mentioned, it is more efficient to climb steeply and then level off to cruise most of the way. Saves on fuel, etc.

    There are lots of great books and learning resources on airplane design and jet engine design. Check out your local library or do some searching on the net. It's a fun subject to study. :-)
     
  18. Jan 6, 2015 #17

    Ryan_m_b

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    A plane can't accelerate for half the journey due to drag. The faster you go the worse drag becomes meaning you have to burn even more fuel.
     
  19. Jan 6, 2015 #18

    russ_watters

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    So, ways around this problem:

    1. Build more airports. (expensive)
    2. Fly planes closer together. (dangerous)
    3. Fly larger planes. (possible!)
     
  20. Jan 6, 2015 #19

    SteamKing

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    The problem with 3) is that the larger planes are more expensive to purchase and their size and the number of people which they carry can lead to 1) which can handle either the size of these planes, the number of passengers, or both. The size of these planes also means that 2) is not only dangerous, but may be lethal to smaller aircraft flying into or out of the same airports.

    The Airbus A380, which is currently the largest commercial passenger plane in production (and the one which can carry the largest number of passengers)

    http://en.wikipedia.org/wiki/Airbus_A380

    has been reported recently to be ending production due to a variety of reasons.
     
  21. Jan 7, 2015 #20

    Borg

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    I was referring to the g-forces. The link to airline restrictions is nice but I've never been questioned about medical conditions like that. In general, people aren't dying from heart attacks during takeoff and landing and the airlines are pretty lax about questioning passengers about their health unless they show up in obvious distress. Increasing g-forces significantly would change that equation.
     
  22. Jan 7, 2015 #21

    russ_watters

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    Something has to give. More people are going to want to fly every year, so the problem you highlighted (airport congestion) is going to keep getting worse. Yes, I'm aware the A380 isn't doing well because carriers are opting for more flights with smaller planes (particularly, budget, domestic carriers). But I think ultimately if they want to grow and they can't get new airport gates or departure times, they won't have a choice but to start flying progressively bigger and bigger planes.

    I understand it is currently not considered a desirable option, but I think it is the least undesirable of the options moving forward.
     
  23. Jan 7, 2015 #22
    Takeoff itself takes relatively little wasted time. Conventional takeoff allows the plane to get up to speed and begin it's parabolic ascent/trajectory. What benefit would VTOL give? Getting altitude is the least of the concern, why waste fuel which could be used for horizontal velocity (which creates lift itself) on only vertical lift, which doesn't get you any closer to your destination.

    The only benefit of VTOL, maybe, would be the reduction in runway traffic - which is admittedly a huge time waster. But you'd still have to account for air traffic. 200 planes can't just take off in 200 different directions at once...
     
  24. Jan 7, 2015 #23

    Doug Huffman

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    It is not difficult to think of air travel as having reached some sort of point of diminishing returns, as being saturated. Bigger, faster AC make longer more frequent ground transportation delays at the airports capable of handling them. A common trip is to a regional airport for access to a hub without ground traffic delays.

    With other air travel inconveniences and expenses those of us with more time to spare than money may find intracontinental ground travel preferable. I can afford to drive to a bicycling event to which I could not afford to fly my bicycles and for just a fraction more time.
     
  25. Jan 7, 2015 #24

    SteamKing

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    Airlines seem to have been working overtime to drive passengers away in recent years. More fees, especially on checked baggage, crowded cabins, fewer, if any, amenities during flights, etc.

    People used to complain about airline food; on many flights, you're lucky if you get a bag of peanuts.

    I used to fly regularly on one of the regional carriers in the US before deregulation. Even without first class, it was a much better experience before deregulation than afterwards. At least, if your flight had a leg which was at least an hour in duration, you got a basic meal with your ticket. Also, this was before the hub concept was adopted wholesale by the airlines. If your flight didn't pass thru one of the congested airports like Atlanta or Chicago, it was a relatively painless experience. Now, unless a flight is relatively short, it's an experience to be endured rather than savored.
     
  26. Jan 8, 2015 #25
    why not diminish the area needed to land/take off planes, by installing helicopter-like mechanisms to airplanes for taking off and landing?
    and diminish the time required to occupy a whole area (landing aisle)? if the airplane lands within seconds, instead of tens of minutes
     
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