New Gen AirShips - Hybrid Air Vehicles, UK
Not to mention G/S Beags
So dim-witted US Army types, who don't understand that the alleged 'cruising speed' cannot be achieved with certainty, might perhaps need to think again about the ridiculous claims for blimps made by airship snake-oil salesmen...
Perhaps the grunts have also discovered the effect of W/V on TAS? oo-rah...
Sorry Beags: Just clarifying an (unintentional) ambiguity.
W/V not of course actually having an effect on TAS, rather the outcome of the combined effects of W/V and TAS on the resultant G/S.
If you see what I mean...
Sorry Beags: Just clarifying an (unintentional) ambiguity.
W/V not of course actually having an effect on TAS, rather the outcome of the combined effects of W/V and TAS on the resultant G/S.
If you see what I mean...
Last edited by Haraka; 25th Oct 2013 at 06:17.
US Army sells cancelled LEMV airship to original designer
Still, the Army is interested in what the Cardington-based company does with the hybrid airship. “Should they fly again, we will receive data from their flight,” Cummings says.
LEMV en route to Bedfordshire
I can't verify the source (a chap called Trevor Monk) but I have no particular reason to disbelieve it:
The Long Endurance Hybrid Air Vehicle (the HAV 304) is now just leaving the USA packed up in around a dozen ISO containers, and will arrive in Liverpool in a week's time. A week after that it should be in Bedfordshire. We'll let everyone know in due course where it will be, and of course there will be plenty of milestones next year when it gets air inflated, shown off to the public for the first time, helium inflated, re-put together and then first UK flight later in 2014...then on its way to type certification. Watch this space!
Oh great, the snake oil salesmen are back in the UK after being shown the door by the USA...
Let's hope there aren't too many Army/Marine idiots in CAP ISTAR at the moment!
LJ
Let's hope there aren't too many Army/Marine idiots in CAP ISTAR at the moment!
LJ
As I understand it there's not much 'allegedly' about the whole thing. It was designed and put together in 18 months and it's the first of its kind so it is most likely to have some problems. Read about the errors and problems in the first iPhone demo and then reflect on iPhone sales since then.
As for He availability, there are quite a few other uses for it and I was at a talk given by the Skylon people who use Helium as the heat transfer fluid from the fuel to the heat exchanger that cools incoming air. You don't want to put hydrogen through metal pipes because it makes them brittle so helium is used in a loop instead. One problem is that the system has to dump some of that Helium at one point in the flight to prevent some sort of overexpansion problem or other. Their take on it (apart from there being less desirable design alternatives) was that there are other sources of Helium that are not being tapped at the moment and that attractive prices would no doubt encourage people to bring these things online. Who knows?
I certainly haven't seen a very informative list of sources and potential production. I've also no notion of the quantity being used for cryogenics vs the amount used in Airships but presumably liquid helium is much denser than the gas so it could be a relatively large amount. So I don't feel like panicking based on so little information.
I did find this on wikipedia which suggests that we have a lot more problems with other uses of Helium than airships, perhaps:
http://upload.wikimedia.org/wikipedi...eChart1996.jpg
As for "it will run out eventually"....well I'm sure that we'll use it as a reason for mining in space.
As for He availability, there are quite a few other uses for it and I was at a talk given by the Skylon people who use Helium as the heat transfer fluid from the fuel to the heat exchanger that cools incoming air. You don't want to put hydrogen through metal pipes because it makes them brittle so helium is used in a loop instead. One problem is that the system has to dump some of that Helium at one point in the flight to prevent some sort of overexpansion problem or other. Their take on it (apart from there being less desirable design alternatives) was that there are other sources of Helium that are not being tapped at the moment and that attractive prices would no doubt encourage people to bring these things online. Who knows?
I certainly haven't seen a very informative list of sources and potential production. I've also no notion of the quantity being used for cryogenics vs the amount used in Airships but presumably liquid helium is much denser than the gas so it could be a relatively large amount. So I don't feel like panicking based on so little information.
I did find this on wikipedia which suggests that we have a lot more problems with other uses of Helium than airships, perhaps:
http://upload.wikimedia.org/wikipedi...eChart1996.jpg
As for "it will run out eventually"....well I'm sure that we'll use it as a reason for mining in space.
I am usually quite thick, but notwithstanding my limitations, the boiling point of Helium is -268 deg C and the boiling point of Hydrogen is -252 deg C. To my mind they are both chuffing cold in their liquid state, and become gaseous at similar temperatures (within 16 degs C). So why does Hydrogen make metal (whatever element that metal may be) brittle, but not Helium?
I am afraid I lost the will to live after reading "cryogenics".
I am afraid I lost the will to live after reading "cryogenics".
By cryogenics I meant the techniques that are uses to cool superconducting magnets in magnetic resonance imaging machines and so on. As I understand it, it's a general term that has been hijacked by the freeze-you-when-you're-dead bunch but it just encompasses the general field of the use of very cold liquids. I'm no expert and I may be using incorrect terminology but I think I'm just repeating what I've read. Helium is used in all sorts of medical, industrial and space applications many of which use quite significant amounts.
RE Embrittlement: I'm not a materials scientist or a chemist so I can only turn to wikipedia:
High strength nickel-steel alloys and titanium are exactly what spaceships/spaceplanes tend to be made of. More specifically for Reaction Engines, their heat exchanger that cools incoming air is made of very fine tubes with walls that are thinner than a hair (makes the heat transfer efficient) and to be strong enough they are made of a nickel alloy. If you ran hydrogen through them, they'd become brittle apparently. But it's the hydrogen fuel that is the heat-sink so there has to be some other fluid to transfer heat from the incoming air to the fuel. Helium is best, apparently.
Sorry for the digression.
RE Embrittlement: I'm not a materials scientist or a chemist so I can only turn to wikipedia:
The mechanism starts with lone hydrogen atoms diffusing through the metal. At high[clarification needed] temperatures, the elevated solubility of hydrogen allows hydrogen to diffuse into the metal (or the hydrogen can diffuse in at a low temperature, assisted by a concentration gradient). When these hydrogen atoms re-combine in minuscule voids of the metal matrix to form hydrogen molecules, they create pressure from inside the cavity they are in. This pressure can increase to levels where the metal has reduced ductility and tensile strength up to the point where it cracks open (hydrogen induced cracking, or HIC). High-strength and low-alloy steels, nickel and titanium alloys are most susceptible.
Sorry for the digression.
Last edited by t43562; 29th Nov 2013 at 07:58.
Let's hope there aren't too many Army/Marine idiots in CAP ISTAR at the moment!
Errr.... Does anyone know why it didn't fly back across the pond?
The quote above indicates that they intend to get it type certified. Presumably one can't fly any old where without this. Again, I don't know the person who said it and I am not sure exactly how they know so take it with as many pinches of salt as you like.
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Round about the turn of the century, I was working for that much derided campaign against aviation (parts of it actually applied their rulessensibly - but not, I suspect the interface between licensing/licenceholders/applicants for licences).
One fine day an enthusiastic gentleman had managed to wangle a meeting concerning use of airships; having nothing better to do (it was the campaign, remember) I was inveigled to participate in the meeting, along with some flt ops and engineering types (my area of responsibility lay with aerodromes). The proposal was for an airship/hybrid that resembled a large M&M sweet, but about 150ft in diameter, with four prop engines placed at the 90 degree points on the circumference.
The operation mooted was a service between Heathrow and Frankfurt airports. The presentation was a bit whacky, and between suppressed giggles from some of the CAA audience, we managed to highlight some potential operating constraints (for which read “difficulties”). Not the least was how to integrate the large, slow moving, relatively unmanoeuvrable chunk of fabric into the approach pattern for two very busy airports. Then there was the problem of where to park the Frisbee, if it was ever allowed access. However, this did not daunt our intrepid entrepreneur; Plan B was to use the large rivers that flowed through the two cities targeted. Right… The practicalities of trying to find a landing place on the Thames of the Main were discussed (and dismissed almostout of hand – Port of London Authority (and whoever controls German rivers) notwithstanding, there isn’t actually much space on the rivers to operate sucha craft, given the amount of other surface traffic that use them).
Plan C then… Hackney Marshes, or any other large open space within easy reach of the two cities (again, notwithstanding permission from the controlling authority, what about all those football pitches that would be disrupted). You can probably guess how the meeting wound up… don’t call us, because we certainly won’t call you.
The point I’m making is not aimed at the craft themselves (I’m sure there is a role for them), but for civil use there is limited (or non-existent) scope for viable commercial operating locations, at least as far as passengers are concerned (freight might be a discussion for another day).
Just another perspective to fill some gaps in the big picture
Mister B
One fine day an enthusiastic gentleman had managed to wangle a meeting concerning use of airships; having nothing better to do (it was the campaign, remember) I was inveigled to participate in the meeting, along with some flt ops and engineering types (my area of responsibility lay with aerodromes). The proposal was for an airship/hybrid that resembled a large M&M sweet, but about 150ft in diameter, with four prop engines placed at the 90 degree points on the circumference.
The operation mooted was a service between Heathrow and Frankfurt airports. The presentation was a bit whacky, and between suppressed giggles from some of the CAA audience, we managed to highlight some potential operating constraints (for which read “difficulties”). Not the least was how to integrate the large, slow moving, relatively unmanoeuvrable chunk of fabric into the approach pattern for two very busy airports. Then there was the problem of where to park the Frisbee, if it was ever allowed access. However, this did not daunt our intrepid entrepreneur; Plan B was to use the large rivers that flowed through the two cities targeted. Right… The practicalities of trying to find a landing place on the Thames of the Main were discussed (and dismissed almostout of hand – Port of London Authority (and whoever controls German rivers) notwithstanding, there isn’t actually much space on the rivers to operate sucha craft, given the amount of other surface traffic that use them).
Plan C then… Hackney Marshes, or any other large open space within easy reach of the two cities (again, notwithstanding permission from the controlling authority, what about all those football pitches that would be disrupted). You can probably guess how the meeting wound up… don’t call us, because we certainly won’t call you.
The point I’m making is not aimed at the craft themselves (I’m sure there is a role for them), but for civil use there is limited (or non-existent) scope for viable commercial operating locations, at least as far as passengers are concerned (freight might be a discussion for another day).
Just another perspective to fill some gaps in the big picture
Mister B
Last edited by HTB; 4th Dec 2013 at 10:03. Reason: formatting text from cut 'n paste
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I am surprised that this topic has lasted so long - every few years we go through the same nonsense about breakthroughs in airship development until the current company goes out of business.They have one insurmountable weakness - the vagaries of weather,low airspeed and high winds are not compatable.You can build some high tech marvel but the fact is they fly too slow.
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PA
Ooh, you cheeky boy; you know full well what I mean, and it didn't involve handbrakes or houses
Anyway, If I had been an admin wallah, I wouldn't have qualifioed to post on here (according to the description in the thread title... nothing would leave the ground)
Mister B
Ooh, you cheeky boy; you know full well what I mean, and it didn't involve handbrakes or houses
Anyway, If I had been an admin wallah, I wouldn't have qualifioed to post on here (according to the description in the thread title... nothing would leave the ground)
Mister B