Underslung Loads

Discussion in 'Aviation' started by CutLunchCommando, Oct 20, 2009.

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  1. Another Ladybird book question from me I'm afraid chaps. I assume that underslung loads make helis difficult to handle during horizontal motion with their inertia and so on. Having seen the picture below I also wonder what their aerodynamic (non)contribution is. Towed sensor packages for gravimetry and the like are streamlined but obviously this cant be done for a really bulky loads like the one below. However has there ever been any work done on a streamlined cargo container that would make it easier to carry smaller loads over longer distances? Is it even a problem?

  2. I would say that most/many underslung loads are sort of quick time jobs, organised by the men on the spot and there really is no need or time for anything 'Fancy'.
    Areodymamic loads would be an invoved matter as there have been instances where 'Loads' have climbed, a Beaver had to be dropped back in the Aden days. Myth/ledgend had it that the Beaver climbed along side the lifting Wessex, so bye bye.
  3. If you want to carry a smaller load over longer distances, you put it inside. If it is to go further, surface means or further again, fixed wing.
  4. Absolutely, but you can't put it inside a K-Max or similar. Also where you can load it internally putting it inside means landing the aircraft and un/loading it with a resulting loss of flying time and possibly having to hang about where someone might have a go at the a/c.

    Subsequent to my OP I thought of a (tenuous) example. The Skycrane was capable of carrying containerised loads though the containers weren't underslung in the same sense.


    The Chinnook in the picture below has some sort of rope arrangement attached. Is it purely for ground handling or is there a flight stability component?


  5. Probably ground handling. Underslung is only used for very limited loads over very limited distances - it isn't a very efficient way of moving large heavy objects.

    Why would you think there was a need to move large (ish) heavy loads underslung over distance? I'm all for asking questions, but I'm trying to see a valid reason here.
  6. I think the lines at the back of the Chinny are to stabilise the load in forward flight, otherwise, if it turns sideways on it'll make life unpleasant for the Skycrane crew. I'd expect to see a few more taglines attached if it was for handling. But then, they're cousins, so all bets are off.

    I've shifted pairs of 48 gallon drums of helifuel about under a Lynx, and you can feel the load swinging about. As jonwilly mentioned, underslinging aeroplanes is a hazardous undertaking, but every load can misbehave. In 85, Chindet dropped the laundry container that should have gone in to Kellys Garden into PSC instead when it decided to try to fly the airframe, and i've been on a flight where the tasking agency gave us the wrong weight for a Rapier genny - when we tried to stop at the delivery end we almost ran out of power and ended up dumping the load. A mate did something similar at one of the Romeos and let go a JCB, I think.

    It's a nice capability to have, if you need to shift stuff that won't go in the back and you need it lifting in or out of a tight spot, but it needs regular training and very careful planning.

    Edited to add; almost forgot the cargo-net full of Chairs, Comfy General Officers For The Use Of, that ended up in the Weser rather than upon its sunny bank one bridging demo.
  7. I'm just wondering if anyone has tried to make moving underslung load (where other options are not viable or may be risky) more efficient in the way that containerisation has for shipping. I'm not actually thinking of anything paticularly heavy or particularly bulky as it happens, just could the manual handling and flying constraints be optimised. As you have pointed out increasing distance and/or mass rapidly lead to other options being the most efficient ones but within that window can/has anything be done?

    For instance, the remote control K-Max is being proposed as an option for US Ops in Afghanistan. Presumably Kaman think that they have an answer to a DoD question with it but it can do nothing except underslung loads. It just promted me to wonder whether it had ever been addressed before.
  8. meridian

    meridian LE Good Egg (charities)

    I think the the KMax is more or less exclusively used for outsize and heavy loads that simply could not be carried internally like power pylons, construction equipment and logs etc and over short distances.

    For short distances though as a way of supplementing Chinook or Merlin etc then why not, seems like a reasonable idea. They are cheap as chips to buy and run and the remote thingy seems to enable non pilots to use them as most if not all the journey is done autonomously.

    I think it has been trialled before




    Worth a look?

    Can we have a look down the back of the sofa for some spare change :D
  9. Never mind the helicopter! WTF is that!
  10. Sorry, to be clear I didnt mean the load would generate its own lift in forward flight but that it would be streamlined to minimise drag. Mind you stub wings seem to work on MI-8 OK so why not modify the load rather than the a/c. :D
  11. meridian

    meridian LE Good Egg (charities)

    Flash or one of the others best qualified would no doubt be able to advise more but I think wings on helicopters are a double edged sword, something to do with limiting the down force I think, might be talking bollox on that though :D

    That boat thing is a demonstration/training vessel I think

    What does everyone think about that unmanned KMax then, would it reduce the need for a lot of road moves and relieve pressure on the hard pressed SH fleet
  12. In my day

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