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AirLander take off then 2nd Flight Mishap

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AirLander take off then 2nd Flight Mishap

Old 20th Aug 2016, 15:29
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Originally Posted by RatherBeFlying View Post
Serious tethering is required to avoid venting of expensive helium.

Then ballast must be sourced in said remote location.

Perhaps lay hose to body of water. Weight of hose will reduce payload, so can't go too far.

That or compress helium back into cylinders
If you bothered to read the links that were provided above, that question would be answered.
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Old 20th Aug 2016, 15:31
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Originally Posted by Scuffers View Post
Again,

What's the killer application?
Again, like nearly all technology we won't know until after the fact.

Military Fixed wing aircraft were developed for spotting for artillery.

Nobody saw other uses initially.
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Old 20th Aug 2016, 18:15
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Again,

What's the killer application?
How about this?

So what sort of roles could it perform? While operating costs are extremely low, donít expect the Airlander 10 (or the larger Airlander 50) to replace 300-seat airliners on transatlantic flights. However, there could be useful niches in aerial sightseeing where this slow, stable flying vehicle could find a market. Indeed, while the Airlander is currently powered by four diesels, HAV say it is already looking at swapping the forward engines for electric powered thrusters. The idea here, says the company, would be to use the rear diesels for take-off, then switch to the forward electric engines for cruise. For zero-emission, silent aerial cruises over natural wonders like the Grand Canyon or African Savannah this could be a green way of seeing the planet Ė and spark off a new environmentally-friendly aerial tourist industry. Further in the future, it is not too difficult to imagine how solar-panels on the top surface, powering electric motors, could make Airlander even more green.
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Old 20th Aug 2016, 18:24
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Wonderfull!

(no really...)
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Old 20th Aug 2016, 18:32
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Lighter-than-air craft, dirigibles, blimps and airships et al, are hardly new technology. In fact they predate fixed wing flight. The steam powered Giffard Dirigible Airship first flew on 24 September, 1852.

The U.S. Army, Navy and Air force, plus Northrop-Grumman, Goodyear, and Fuji know what airships are good at. The question is, and always will be; Is it practical, profitable and relevant?
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Old 20th Aug 2016, 18:40
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Is the Airlander, technically, lighter than air?
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Old 20th Aug 2016, 18:44
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Reading the Zeppelin write-ups, what comes across most clearly is how fragile these leviathans actually were and how safe operations were maintained only by continued heroic effort on part of the crew.
Indeed, prudence above all was the mantra of Hugo Eckener, the guru of post WW1 LTA travel. Whenever it was disregarded, disaster followed. Yet any sort of reliable tourism service mandates that the schedule hold priority. That is a serious conflict imho.


The Airlander promises to materially widen the margin of safety in some aspects, but its reliance on dynamic lift adds new issues. Meanwhile, the old airship problems of wind and precipitation impacts on the hull have not really been addressed, much less resolved.
Color me deeply skeptical.
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Old 20th Aug 2016, 18:59
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Airlander lighter than air? Could be.. Hot air is lighter (less dense) than cold air, so is helium and hydrogen, so a static experiment in calm wind conditions would be able to determine if the Airlander could ascend without aid of external power and airfoil effect, thereby becoming lighter than the surrounding air.

Check out the definition of Airship:
https://en.wikipedia.org/wiki/Airship
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Old 20th Aug 2016, 19:27
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Is it practical, profitable and relevant?
Whether we like it or not, it is likely that someday in the not-too-far future we're going to have to cut back on the Jet A-1.
Airships, with their large surface area, are a good candidate for practical solar powered flight. Note that the ceiling of the Airlander (20,000 ft) would allow it to fly well above average cloud cover, allowing mostly unrestricted access to sunlight on a few thousand square meters of solar cells.
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Old 20th Aug 2016, 21:15
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Solar Lander?

Originally Posted by olandese_volante
Whether we like it or not, it is likely that someday in the not-too-far future we're going to have to cut back on the Jet A-1.
Airships, with their large surface area, are a good candidate for practical solar powered flight. Note that the ceiling of the Airlander (20,000 ft) would allow it to fly well above average cloud cover, allowing mostly unrestricted access to sunlight on a few thousand square meters of solar cells.
(SLF - revisiting my ridiculed post in the solar impulse thread)

Actually - the area of the Airlander 10 is nearly 4000 m^2. This, covered in solar cells at 30% efficiency is nearly enough to run its engines at full power. (4x365hp vs. 1200kW of solar power)

I admit, these numbers are over simplified, neither do I have an idea of the mass of that many solar cells, but I suspect a larger Airlander 50 will have more area and more lifting capabilities, so it might be feasible to build a craft whose loiter time is not defined by fuel or FTL but when the crew needs to go on vacation or their tour of duty ends. ;-)

I think there are solar cells out there that sacrifice some efficiency for massive reductions in weight, they might be the right thing for this application. Someone in this thread wrote they're thinking about shutting down half of the engines during cruise - maybe, talking about lighter electric motors, there is a realistic chance that the two usually shut down engines might also be replaced by two electrics plus some batteries?

What do you all think?
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Old 20th Aug 2016, 21:54
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What do you all think?
1) 30% efficiency for solar cells in practical applications is a bit of a stretch, I'd settle for half that.
2) Electric motors are lighter than diesels of equal power output, but at least some battery capacity will be required and this adds weight too.
3) First steps might involve hybrid propulsion: use the diesels when you must, use the solar-powered electrics when you can. Diesels could also top-up the batteries if required.

In other news, NASA is currently building a prototype electric fixed-wing aircraft, the goal being to achieve at least one hour of flying time and a range of about 100 miles on batteries alone.
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Old 20th Aug 2016, 22:59
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Originally Posted by olandese_volante
In other news, NASA is currently building a prototype electric fixed-wing aircraft, the goal being to achieve at least one hour of flying time and a range of about 100 miles on batteries alone.
(SLF again, slightly drunk at this time of day)

I don't know about the NASA prototype, but I have the nagging feeling this is a solved problem.

An Echo-class aircraft probably can carry the mass of the Tesla power train. I have no exact numbers, but I guess 400kg just batteries and associated electronics. An echo-class GA aircraft usually has an engine in the 150-200 hp range, quite a bit less than the Tesla. I've been told the Tesla can cruise at high power (German Autobahn) for nearly an hour. *thinks* latest battery version @100kWh should deliver nearly 75% power to an Echo-Class aircraft for an hour...

Now, imagine an aircraft as efficient as the SEA Risen (ok, as LSA, it won't nearly carry that battery pack)... maybe the Pipistrel Panthera... (Pipistrel Panthera - Plane & Pilot Magazine)... it should work.

I don't claim we have electric flight yet, but we're friggin' close...
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Old 21st Aug 2016, 07:05
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Old 21st Aug 2016, 08:06
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Current Tesla battery is some 544 kg (85 kWh) without any electronics, cooling, etc.

Solar panels are not zero weight either, and 1+Mw of them is going to make a big dent in the payload capacity.
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Old 21st Aug 2016, 08:43
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Originally Posted by Scuffers View Post
Current Tesla battery is some 544 kg (85 kWh) without any electronics, cooling, etc.

Solar panels are not zero weight either, and 1+Mw of them is going to make a big dent in the payload capacity.
A lot of that weight is the frame, in a car the weight is a lower priority.

The solar panels on the aircraft that just flew around the world are pretty light.

The dent in the payload capacity is going to shrink the longer you intend to fly compared to fuel for an engine.

Electric motors are far lighter per watt than IC engines, more reliable and less maintenance.
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Old 21st Aug 2016, 08:53
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There's not that much helium left in the world. It keeps on floating into outer space as we tract it, and we have not got a pipe to the sun to syphon off some more.

Unless we get the fusion thing sorted to create unlimited energy, the economic lifespan of a craft like this has to be limited from that point alone.
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Old 21st Aug 2016, 09:22
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Originally Posted by compressor stall View Post
There's not that much helium left in the world. It keeps on floating into outer space as we tract it, and we have not got a pipe to the sun to syphon off some more.

Unless we get the fusion thing sorted to create unlimited energy, the economic lifespan of a craft like this has to be limited from that point alone.
Factually incorrect.

Oil will run out before helium.

That Dire Helium Shortage? Vastly Inflated | WIRED

https://www.sciencenews.org/article/...ot-running-out

Forbes Welcome

https://www.newscientist.com/article...nners-running/

Helium shortage could be solved by new life-saving discovery | Science | News | The Independent
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Old 21st Aug 2016, 09:48
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Set a decent price for Helium and you'd be amazed at how much would be available - currently it's mainly a by-product of other activities and is really a pain rather than a profit for the industry concerned
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Old 21st Aug 2016, 13:10
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Originally Posted by Tourist View Post
A lot of that weight is the frame, in a car the weight is a lower priority.

The solar panels on the aircraft that just flew around the world are pretty light.

The dent in the payload capacity is going to shrink the longer you intend to fly compared to fuel for an engine.

Electric motors are far lighter per watt than IC engines, more reliable and less maintenance.
No matter if it's in a car or a blimp, you still need to physically hold/contain the battery cells, and to make out weight is unimportant to Tesla is laughable.

The plane that went round the world did not have 1+Mw of panels on it, and light as they were, they still weigh something, as will the interconnects, supports, etc.

then we get to the motors, they themselves might be light, they still need to be cooled, that adds significant weight.

then consider just how much electronics/control gear required, it's cooling, weight of wiring, etc etc.

as for reliability, current breed aero engines are hardly unreliable.

I'm not against solar power, just please pick a practical application for it.
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Old 21st Aug 2016, 13:40
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Originally Posted by Scuffers View Post
No matter if it's in a car or a blimp, you still need to physically hold/contain the battery cells, and to make out weight is unimportant to Tesla is laughable.
I didn't say unimportant, I said lower priority.
Just like in a sports car the weight of the engine is less important than it is in a light aircraft.
It's a perfectly valid point. In a sportscar rigidity is rather more important than in a soft blimp.
Deliberately misquoting me is rude.

Originally Posted by Scuffers View Post
The plane that went round the world did not have 1+Mw of panels on it, and light as they were, they still weigh something, as will the interconnects, supports, etc.
No, it had 66Kw over an area of 269.5 m2 at 135 micron thick. Not exactly heavy duty.
Airlander has more than 3500m2 to play with on top.

To be fair, I doubt that the durability is there yet, but the photovoltaic area of research moves very quickly at the moment.

Originally Posted by Scuffers View Post

then we get to the motors, they themselves might be light, they still need to be cooled, that adds significant weight.
Totally depends how they do it. Huge numbers of small motors seem to be the way ahead in current thinking on flying electric aircraft. No cooling required.

Originally Posted by Scuffers View Post
then consider just how much electronics/control gear required, it's cooling, weight of wiring, etc etc.
These are problems for any aircraft of any type. To try to suggest that they are somehow worse for an aircraft that gets upwards of 60% of its lift for free is disingenuous.
Due to the lack of load on control surfaces compared to an airliner, all runs can be much lighter.

Originally Posted by Scuffers View Post
as for reliability, current breed aero engines are hardly unreliable.
Nope, I didn't say they were. I said less reliable and more maintenance.
Originally Posted by Scuffers View Post

I'm not against solar power, just please pick a practical application for it.
I've got to say, that I struggle to find a more obvious application than a long endurance blimp.
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