While sustainable aviation fuel and electric flights are being talked about, there is another form of air travel that has been touted as a green alternative to flying: the airship.
Technically, an airship is all hot air: a self-propelled aircraft, typically cigar-shaped, made from a large balloon filled with nearly weightless buoyant gases, with an attached car or gondola to transport passengers, crew, and cargo. If it conjures up a black-and-white image of the past, you’re right—airships were popular in the early 20th century, before the rise of aviation as we know it. And now, they’re making a comeback.
Modern technological advances, combined with the need to improve the aviation industry as it slowly struggles towards net zero, have led aeronautical engineers to re-examine airships. New materials developed since its heyday—including new forms of ultralight nylon—have made a new type of aircraft possible. Replacing flammable hydrogen with helium has enabled safer development and is intended to prevent a repeat of the disaster of the luxury German airship Hindenburg, which exploded live on film in 1937. New developments and stronger aviation standards mean that the only features these new airships have in common with the Hindenburg are their shape and the use of a lighter-than-air gas.
Though an airship, which typically flies at around 100-130km/h, won’t ever reach the speeds of a jet plane, they are talking about being about as forms of slow travel like cruise ships and night trains, where the experience makes up for the speed Airships fly at a lower altitude than a plane, with unpressurized cabins where you can open and look out of the window, making it more comfortable for passengers. The large balloon also takes far less energy to power – and potentially could operate with electric engines powering liftoff and steering, making them a zero-carbon emitting form of air transport.
“It’s good that we are testing different ideas and innovations, as exploring various solutions is key to improving aviation and making it more sustainable in the future,” said leading aviation expert Thomas Thessen, adjunct professor at the University of Aalborg and chief analyst at Scandinavian Airlines. “The biggest advantage I can see is that they can stay in the air for a long time, and their ability to fly vertically up.”
Airships don’t need a runway to take off, meaning they can land and take off anywhere there’s a flat area big enough for them, this could be somewhere as simple as a field, as long as there’s something to tie it down to. This also means they can help save people in natural disasters where the internet and phone may be disabled.
The world’s largest aircraft, LTA Pathfinder 1, is currently being tested in Silicon Valley in California. Measuring 124.5 m x 20 m, the next-generation airship is equal in size to four Goodyear airships and longer than three Boeing 737s. LTA, which stands for “Lighter Than Air”, is one of a handful of airship manufacturers in the world currently preparing to enter the aviation market. The company, founded by Sergey Brin, the former chairman of Alphabet, Google’s parent company, believes the next generation of airships could reduce aviation’s carbon footprint by using helium inside the balloon to do lift instead of a carbon-emitting jet engine and using much smaller engines for propulsion. Applications for its airships include more efficient cargo transportation point-to-point (rather than port-to-port) and humanitarian aid, where the airship can support relief efforts even if runways, roads, and ports are damaged.
They are not alone: The French company Flying Whales is also developing airships for cargo purposes, aiming to reduce the environmental impact of cargo transportation; British company Hybrid Air Vehicles (HAV) focuses on how zero-emission air travel can be possible with a hybrid airship that uses helium as well as electric motors.