Three months ago, on 10 August, the off-white, doughnut-like prototype of a revolutionary unmanned airship took off from a New Jersey airfield in the latest attempt to break the curse of the Hindenburg. The crash of the flaming Nazi airship in front of the world's media in 1937 put a brake on the development of a technology that was labelled as promising then, and still is today, 70 years later.
It is hoped that this $154m (£96m) half-plane, half-airship hybrid, or Long Endurance Multi-Intelligence Vehicle (LEMV), designed and built for the US defence giant Northrop Grumman by the Milton Keynes-based Hybrid Air Vehicles (HAV) and funded by the US Army, will be the first of a new generation of airships. That it will – for example – loiter above the deserts of Afghanistan tracking the Taliban for weeks at a time or, as bigger Airlander heavy-lift transporters, carry ore from an Alaskan mine to a factory floor in one go.
Chief executive Gary Elliott is confident even if HAV receives little UK government support, the LEMV is "simply a game-changer". He says: "Back in 2000 we sat down and listed all the foibles and problems of the traditional airship and come up with a design that is all about removing them and delivering practical, reliable and cost-effective vehicles. And the flight of the LEMV proves that the design works."
Hardy Giesler, HAV's business development director, says: "Even though the first flight was delayed, 26 months from PowerPoint presentation to prototype is still pretty impressive."
The dream of lighter-than-air flight began with the demonstration by Bartolomeu de Gusmao in 1709 that it was possible and then grew with early pioneers such as Henri Giffard, who flew his steam-powered airship in 1852. In 1901 airships really caught the imagination when a Brazilian, Alberto Santos-Dumont, built the first practical airship and flew it round the Eiffel Tower, thereby winning the Deutsch prize of 100,000 francs offered for creating the first machine capable of flying a round trip from the Parc Saint Cloud to the tower.
After playing a powerful role in the public mythology of the First World War – if a relatively minor military role as a bomber, transporter and patrol craft – airships hit the big time in 1919 when the British R34 made a successful return flight across the Atlantic; in 1929 the German Graf Zeppelin travelled round the world in 12 days. Yet, just eight years later, the Hindenburg disaster seemed to herald the end of the dream even if the US Navy continued to use airships on anti-submarine patrols in the Second World War.
Airships have never entirely disappeared, but all the dreams and false starts have amounted to little more than the Goodyear Blimp's being mistaken for a UFO as it hovered over London's Olympic Park this summer and one American company offering guided tours for small parties aboard one.
Now, primed by $500m of Department of Defence spending and backed by a positive Congressional Budget Office report last year, Hybrid Air Vehicles is just one new airship firm competing to launch a cost-effective alternative to Sentinel UAVs (unmanned aerial vehicles, or drones) in both a surveillance and load-carrying roles.
The LEMV, for example, can carry a payload of 2,500lbs, far more than any other unmanned vehicle. The Airlander 200 will be able lift two battle tanks, while the Hercules transport aircraft is unable to carry any and the C-17 can carry only one.
For Elliott, this renaissance is only possible as "together with a great design and configuration the individual technologies that make it up have all come to maturity at the right time", such as creating a single skin out of Vectran, Kevlar and Mylar rather than cow hides to protect it against small-arms fire. The credibility of the technology in the eyes of potential purchasers has also increased, he says, because "we have flown and it works and the US Army is a customer".
HAV is also having daily conversations with the UK military. Giesler says: "In the past projects have stretched themselves too far; we have instead focused on tried and tested technologies to make it as credible as possible."
The American airship expert Ronald D Hochstetter says: "It's really an exciting time as airships are now where airplanes were in 1911, with lots of competing pioneering designs, each with the potential to be successful. It's not a nail in the coffin of the conventional airship just yet, as the jury is still out whether the hybrid can work in real-world situations where strong winds or storms may cancel out its advantages."
Bill Sweetman, editor-in-chief of Aviation Week & Space Technology's Defense Technology Edition, is sceptical: "Because it doesn't deploy quickly and can't go very high, it pushes them down into niche missions, which upsets the economics.... Who's going to pay for it in a recession? If the military doesn't do it, the last radical transport technology pioneered by the commercial industry was the steamship." But Elliott says: "The baseline is to continue to deliver on the LEMV and at the same time develop the Airlander 50 for a role out in 2014-15. And we employ some of the best engineers in the business to make this dream possible from a base in Britain."
The hybird Blimp: how it works
Conventional airships or aerostats are lighter than air, achieving lift by the use of a gas such as helium or hydrogen with engines for propulsion. But the late British airship visionary Roger Monk realised if you could create a hybrid design that uses a combination of lift produced by the helium and by the aerodynamic shape of the hull and thrust engines, then you'd have a game-changer. The hybrid would be able to carry heavier loads, have more control over taking off and landing, and not need a mooring mast and ground crew to stop the airship floating away. It could take off vertically or horizontally. The Pentagon-backed Aero's RAVB (Rigid Aeroshell Variable Buoyancy) prototype airship that is nearing completion instead pumps helium from cell to cell inside a rigid frame.