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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?
Same as manned spaceflight - the glory days have gone.
This is 300 foot long. The Graf Zeppelin of 1928 was 776 feet long with a useful lift of 60 tonnes.
The Hindenberg was even bigger.
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.
Same as manned spaceflight - the glory days have gone.
This is 300 foot long. The Graf Zeppelin of 1928 was 776 feet long with a useful lift of 60 tonnes.
The Hindenberg was even bigger.
As soon as I saw the picture of it, that's exactly what went through my mind as well. They claim in the write-up that they're some kind of revolutionary fusion of different technologies...it's just a modern blimp with turbofans for thrust and some fins for directional/pitch control. Nothing new to see here, and not even very big when compared to craft of similar nature.
Even more importantly, it's a solution in search of a problem. They originally built it for the military...which means "we thought they'd buy it from us, but they just laughed so we need someone else to give us money now." Note the prominent "Invest in Us" button at lower right.
Also, 10 tons of cargo is NOT a lot of capacity for something of this size. That's 20,000 pounds...while a C-17 can carry 169,000 pounds. A lot of that cargo capacity will be consumed by holding crew and the things needed to support them, as well.
So...in short, what you have is an airship that cannot be parked outside (you would not believe what wind will do to something this big but this light), that cannot go very fast, that cannot carry very much, that probably (given the pervasive use of carbon composites and Vectran in its construction) costs a shit-ton of money to build and repair, and that is made by a company that probably won't be in business much longer. Waaaaaaa hoo.
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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..."
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.