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World's Largest Aircraft Completes Its First Flight (cnn.com)
The world's largest aircraft has finally completed its first flight after months of preparation and years of searching for funding. The Airlander 10 as it's called spent 20 minutes in the air on Wednesday, landing safely at Cardington Airfield north of London. CNNMoney reports: "Part airship, part helicopter, part plane, the 300-foot long aircraft is about 50 feet longer than the world's biggest passenger planes. The Airlander, made by British company Hybrid Air Vehicles, has four engines and no internal structure. It maintains its shape thanks to the pressure of the 38,000 cubic meters of helium inside its hull, which is made from ultralight carbon fiber. The aircraft was originally designed for U.S. military surveillance. But the project was grounded in 2013 because of defense spending cuts. [The team behind the giant blimp-like aircraft] said the aircraft could carry communications equipment or other cargo, undertake search and rescue operations, or do military and commercial survey work. The Airlander can stay airborne for up to five days at a time if manned, and for more than two weeks if unmanned. It can carry up to 10 tons of cargo at a maximum speed of 91 miles per hour. The aircraft doesn't need a runway to take off, meaning it can operate from land, snow, ice, desert and even open water." You can view the historic flight for yourself here (Warning: headphone users beware of loud sound).
Helium is a rare element on Earth, despite being common in space. We need to be conserving our helium supplies. Why are we wasting helium on stuff like this?
If it can carry tons of cargo, why the huge difference in time for manned (5 days) and unmanned (2 weeks)? ... Is it perhaps the size of the portapotty needed for the bricks people on that thing will lay during the voyage?
There is lots of Helium. It is a by product of oil and gas extraction and a huge amount was discovered recently in Africa.
Airships of the past were much bigger. The Hindenberg was 803 feet long (245 meters), more than twice the length of this midget.
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"hey, y'all! watch this!"
Meanwhile, North Korean garlic, chili and cabbage head leader, Kimchi Jong-Un, has announced that they have successfully launched a giant rocket pin, which intercepted "a real big ass balloon".
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
when will US posters finally stop using imperial manner and units when posting, translating foreign information into their own old-fashionned sick measurment units ? is it a flying ship or a myriapod ? (300 feets ... !! )
Fair point, Is suspect someone got confused by the statement:
"The largest aircraft currently flying uses innovative technology to combine the best characteristics of fixed wing aircraft and helicopters with lighter-than-air technology to create a new breed of hyper-efficient aircraft."
and thought that "best characteristics of ... helicopters" meant it's part helicopter, rather than it has some of the abilities of one (i.e. sustained hovering over a location). That's what you get when people don't understand English I guess.
Is that a good idea? Sure, it saves weight, but if it ever suffers partial deflation in the air there will be a total loss of control preventing them even attempting a crash landing as the aerofoils and props start pointing in random directions.
Hydrogen is cheaper and more abundant, but because of one minor setback 80 years ago the idea has been senselessly abandoned.
You have a very curious definition of "one minor setback".
Imagine the same principle was applied to other aircraft and we abandoned the whole idea as soon as one thing went wrong
The problems with other aircraft had solutions. The problem of using highly flammable hydrogen gas is an irreducible hazard. Helium can work as a substitute but our supply is limited on Earth and getting more will be expensive.
Engineering and design methods have improved considerably in 80 years, and we could now likely make a very safe hydrogen airship, but people have an unfounded fear of the idea.
Really? We've solved the problem of hydrogen gas being highly flammable? When did that happen?
It's not exactly a cube/square scaling. Because the larger you make it, the larger the tensile loads per square meter, meaning the stronger the envelope needs to be. Without upgrading to a higher tensile envelope, this means increasing thickness.
If you want to view it from a cross-section perspective, tensile strength is measured in pascals - aka newtons per meter squared (cross section). If we're taking a 1-meter slice, it's newtons per ~meter thickness. Pressure is likewise pascals - newtons per meter squared (area). From the same a 2d slice perspective, that's newtons per ~meter (perimeter). The higher the perimter, the higher the number of newtons force. But the number of newtons the envelope can withstand doesn't have perimeter in its divisor, it has thickness in its divisor. So thickness and perimter cross section must increase in accordance.
"99 dead duelists of Dios on the wall. 99 dead duelists of Dios! Take one's ring, pass it around..."
So can someone explain what the point is?
It targets two major use cases, neither of which can be serviced by a conventional cargo jet or a road vehicle:
1) Ferrying heavy cargo (and possibly people) to or from a land-locked location that lacks a suitable runway or road/rail connection. This is of special interest to the military, but also has civilian applications.
For the military, truck transport through enemy territory is extremely dangerous for obvious reasons - possibly even more dangerous than using an airship, depending on what technology the enemy has access to. An airship may be a big target, but it can also fly high enough that most ground weapons can't even hit it. If it does get hit, a few small holes in the envelope (say, from a machine gun) won't immediately end the mission. A large one is also at least twice as fast as a military ground convoy, and has more tactical options available for avoiding the enemy, since it doesn't need to follow roads.
Truck transport through neutral territory is safe - for the military convoy. It's not safe for the neutral country though, as allowing military convoys to pass their borders may be considered an act of war by the enemy. For this reason, it can be very difficult to get permission from neighbouring countries to use ground transport into a land-locked war zone. Air transport is less problematic (I do not say problem-free) in this regard.
As for conventional cargo jets like the 747 - their survivability probably isn't as much better than an airship as you might think. Big subsonic jets are easy to shoot down for anyone who has access to large 1970s anti-aircraft missiles, like the Sidewinder or the S-300. So, cargo jets won't last long unless the user has air dominance in the area of operations. A lifting-body airship should still be able to fly high enough to keep out of range of small arms like machine guns, and arguably is not that much more vulnerable than a 747 in practice. It would have to stay a bit further from the front lines though, because it cruises low enough to be at risk from short-range stuff like Stinger missiles, and maybe auto cannons.
For any user (whether military or civilian), the advantage of an airship is that it doesn't need a huge, expensive concrete runway at each end of the journey. For the military, taking weeks or months to build such a runway isn't always an option. Even when a suitable runway is available, it could be disabled by the enemy at any time with a few bombs or artillery rounds. For civilian users, there are projects set in remote areas for which the expense and/or environmental impact of installing a city-grade runway is just not worth it. Dirt roads are usually (though not always) an option, but some exceptionally heavy, bulky cargo can't reasonably be moved via a steep, narrow, windy, muddy road.
2) Because airships can stay aloft so much longer before they need to refuel, they are well-suited to loitering over an area to provide a communications relay or an observation platform. This has civilian applications, as well as military. If you only need to cover a relatively small area (hundreds of square kilometres, rather than thousands), they are much cheaper than satellites. The ability to easily relocate them and swap or upgrade the payload makes them more flexible.
Even for military users, their greater vulnerability isn't always a problem: the military is tasked not only with taking enemy territory, but also with patrolling friendly territory. An enemy trying to sneak in cannot shoot down a patrolling airship without revealing his presence.
Would it be at all feasible to cover the top of this thing with thin and semi-flexible solar panels? If Solar Impulse can make it around the planet using just the solar energy hitting its thin little lifting surfaces then surely the surface area of this magnificent flying backside should be able to gather enough energy to shove it across the sky, right?
Going off the Airlander 10 specs:
The vehicle is powered by "4 x 325 hp" diesel engines, for a combined peak power of about 960 kW. Most vehicles do not cruise at peak power continuously, so I will estimate the average power requirement at half of that: 480 kW. (This ratio would be approximately correct for a large subsonic jet; if someone knows what it should be for a diesel-powered lifting-body airship instead, please leave a comment.)
The useful surface area of the Airlander 10 is approximately [92 m long] * [43.5 m wide] = [4000 m^2]. (The exact number depends upon the latitude, the time of day, and the craft's heading, but it turns out that its shape is such that the answer doesn't change much, except near the poles.) Peak solar irradiance (direct sunlight at high noon) at ground level is about 1 kW / m^2, and current thin film solar panels are under 15% efficient. Solar power conversion circuitry is around 90% efficient, and an appropriate electric motor with its controller is about 88% efficient. Therefore, a maximum of [4000 m^2] * [1kW / m^2] * [15%] * [90%] * [88%] = [475 kW] of shaft power could be generated by solar-electric means.
So, a solar-powered Airlander 10 could work - but not very well. Under ideal daylight conditions, it could fly about as well as the hydrocarbon-powered version. However, airships are sufficiently slow and long-range that they are expected to routinely fly through the night. Thus, the average power available must be at least cut in half, to 238 kW. Cloud shadowing (airships can fly over some clouds, but far from all) and dust will further reduce that number.
Additionally, a solar-powered airship needs to carry heavy batteries in order to avoid catastrophic power loss when passing through clouds. One hour's worth of lithium-ion power would mass [475 kW*h] / [86% charge/discharge efficiency] / [200 W*h / kg] / [80% - 20% depth of discharge range limit] = [4600 kg]. As the total mass of the Airlander 10 is only 20 metric tons, it cannot carry much more battery power than that without cutting into the payload.
At cruise, nearly all of the Airlander 10's power is devoted to fighting drag. Since subsonic drag scales with the square of airspeed, a solar-powered version could quadruple its battery-powered run time by halving its speed. (It can't really go any slower than that though, as it needs to be able to overcome typical headwinds to be useful.) Four hours of battery time is still woefully inadequate for an overnight flight though, so a solar-powered version would be limited to daytime flights only, and consequently to overland flights only.
TLDR: A solar-powered version of this airship is possible, but it would be considerably slower and incapable of crossing oceans. Supplemental charging on the ground wouldn't help much at all.