Airships: What They Are, How They Work

The quest for sustainable air travel has sparked a renaissance for these balloon-like craft.

Written by Brooke Becher
Airships: What They Are, How They Work
Image: Shutterstock
UPDATED BY
Brennan Whitfield | Jun 06, 2024

Airships are vertical-lift aircraft that use gas to float and steer in the air. During their heyday in the first decades of the 20th century, these lighter-than-air vessels were both a luxurious passenger service and military-grade weapon. But after the widely publicized Hindenburg disaster of 1937, in which 36 people died when a gas leak caught fire, airships fell out of production and were quickly surpassed by airplanes.

Today, there’s just a couple-dozen airships left — and only half of them are in working order.

What Is an Airship?

An airship, also called a dirigible, is a lighter-than-air aircraft that uses gas (often helium or hydrogen) to float and steer in the air. Examples of airships include blimps and zeppelins.

What Is an Airship?

Airships are lighter-than-air, vertical-lift vehicles that achieve flight by using buoyant gasses that are less dense than surrounding air. Technically, “airships don’t fly — they float,” Oliver Jaeger, an airship pilot at aerostat startup Flying Whales, told Built In.

There are three main types of airships: non-rigid (or blimps), semi-rigid and rigid. Typically, these bullet-shaped craft are filled with helium or hydrogen, and composed of three main parts: a balloon-like hull, a gondola and a propulsion system.

At the height of their popularity, airships were primarily used for luxury travel, cargo delivery and military logistics. Today, they are more commonly seen in advertising, photography, tourism and aerial broadcasting.

Now, a handful of new-age startups, like Hybrid Air Vehicles, Flying Whales and LTA Research, are leading an airship revival. With passenger-boarded liftoff scheduled in the next few years, the hope is to develop modern airships into the “trucks of the sky,” as new, more sustainable players in transportation logistics.

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How Do Airships Work?

Airships rely on gasses — namely helium or hydrogen — to vertically lift and buoy them across the skies. This works because these gasses are lighter than the air surrounding it. Unlike sleeker aircraft modeled for speed, an airship’s massive scale and elongated, cigar-shaped body actually make them even more aerodynamic.

The bigger an airship is, the better, according to Edwin Almanzar, a former airship pilot for the Goodyear Tire & Rubber Company. This is based on two factors — lift and drag. An airship’s lift is directly related to the volume of gas it contains, while the drag depends on the surface area of the aircraft. And, thanks to their torpedo-like build, an airship’s lift increases exponentially in relation to its drag, reducing air resistance for optimal performance.

“About 95 percent of an airship’s lift is provided by its lifting gas,” Almanzar, who is now the chief operating officer at blimp sightseeing tour company Skycruise Tampa, told Built In. “The other 5 percent is provided by its shape moving through the air.”

Thrust generated from a power source — engines, generators or batteries — propels airships forward. Flight controls located in the back of the vessel, like rudders and elevators, adjust the amount of lifting gas and propulsion in order to manipulate the aircraft’s altitude, direction and maneuverability en route.

“Unlike other aircraft, airships do not rely on moving through the air to produce lift,” Almanzar said, noting that these aircraft do not require special infrastructure, like runways or airports, due to their vertical lift capabilities. “This means that [airships] use less fuel and can stay aloft for much longer trips — even days at a time — than other aircraft.”

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Types of Airships

There are three different types of airships — non-rigid (blimps), semi-rigid and rigid. Each design comes with their own set of pros and cons that vary in structural support, control and maneuverability.

Non-rigid

Non-rigid airships are better known as blimps. Like a balloon, they are over-pressurized to maintain their shape in lieu of an internal skeleton. Under the bullet-shaped envelope is a gondola with motors attached. These vehicles are commonly used for advertising, aerial surveillance and sightseeing.

Non-rigid airships are cheaper to manufacture and maintain, and can be inflated and deflated on demand, Jaeger said; however, when compared to rigid builds, they are “less reliable … and very limited in the levels of aerodynamics and structural loads they can sustain.”

Rigid

Rigid airships contain a metal internal framework. Inside the fabric-wrapped hull are a series of gas-filled balloons that store and distribute the lifting gas throughout the ship. Because of its skeletal structure, rigids maintain their shape regardless of gas levels. These models are known for their safety ratings and ability to scale, making them best suited for the cargo market. They have also been used in military applications and for exploratory purposes.

Semi-rigid 

Semi-rigid airships are part-blimp, part-rigid aircraft. So while their streamline shape is still primarily supported by lifting gas under pressure, they also contain a partial metal structure that extends along the base of the ship and supports the car. This allows for better control and maneuverability than a blimp at lighter weight than rigid models. Semi-rigids have been used for passenger transportation, cargo delivery surveillance and advertising.

 

Benefits of Airships

Because of their design, airships have benefits that can make it a preferable vehicle choice for air travel. These benefits include:

  • Airships can take off and land in various locations, without requiring runways or airports.
  • Airships can carry large payloads in comparison to traditional aircraft.
  • Airships require less fuel and can travel for longer distances than other aircraft.
  • Airship cruise speeds are just as fast as land vehicles or trucks, and are faster than those of sea ships.

 

Limitations of Airships

Despite having some advantages over traditional aircraft, airships also have their share of limitations. These limitations include:

  • Airships are susceptible to bad weather, and are difficult to maneuver during storms or strong wind conditions.
  • Airships can be expensive to build and operate due to their size and use of helium or hydrogen gas.
  • Airships can require helium gas — a limited resource — as their fuel source.
  • Airships travel slower than airplanes, making them ineffective for time-sensitive air travel or cargo shipments.

 

Are Airships Safe?

Airships can be considered safe when following modern airship safety regulations during construction and operation. Unlike their earlier iterations, modern airships commonly use helium, a non-flammable gas, as their fuel source. Plus, modern materials, like carbon fiber, offer a safer, less fragile solution to airship construction. Fitting these aircraft with GPS-enabled navigational and weather forecasting systems also would allow them to avoid dicey weather conditions. 

 

A brief history of airships. | Youtube

History of Airships

Fifty-one years before the Wright brothers took flight, French engineer Henri Giffard traveled 17 miles in a steam-powered blimp to mark the first on-record flight of an airship in 1852. The non-rigid vessel paced at six miles per hour. 

Different variations of airships followed, from man- and electric-powered aircraft to models that ran on coal-gas combustion and petrol engines. And so did important events, like the first successful roundtrip, which was completed in 1884 by military-grade dirigible, La France.

But it wasn’t until the early 20th century, when German general Count Ferdinand von Zeppelin invented the first rigid airship, that these aircraft really took off. With its first launch in 1900, this series of zeppelins would become the most successful airships of all time. While many fleets were used to carry out bomb raids and reconnaissance during World War I, one of the more popular ships — the LZ-127 Graf Zeppelin — was a hydrogen-filled, commercial passenger dirigible that tracked more than one million miles over 590 flights, and is responsible for the first flights that crossed the Atlantic and circumnavigated the globe.

The airship’s golden age ended in 1937 following the fatal Hindenburg disaster, where an 800-foot, luxury passenger ship’s spontaneous combustion resulted in the deaths of 36 people. The event led to significant changes in airship design and safety regulations, effectively marking the end of an era for commercial lighter-than-air travel.

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Future of Airships

Airships Can Be a Sustainable Transportation Option

Airships are back in a big way. And it has everything to do with cleaning up air travel.

According to BlueSkyModel, planes produce 53 pounds of carbon dioxide per mile. This adds up to about four percent of human-induced global warming, which is set to triple by 2050.

As a result of public and private interests shifting to favor things like sustainability, “what we are experiencing right now is an airship renaissance,” Jaeger said. Back in the day, when airships were the preferred choice for luxury travel, they were the fastest option by default and sustainability was not yet a concern, he added.

“Today the situation is very different,” Jaeger said. In terms of logistics, manufacturing and long-term care, airships have the potential to be a cost-efficient competitor to current transportation standards. They would also dramatically reduce greenhouse gas emissions, and require minimal infrastructure.

“What we are experiencing right now is an airship renaissance.”

For example, Flying Whales’ helium-filled, electric-hybrid airships can carry up to 60 tons of cargo at a time, and produce less than a tenth of the carbon emissions than that of a helicopter.

Hailing from the United Kingdom, Hybrid Air Vehicles are developing a double-barrel airship called the Airlander. Its flagship model — which is designed to reduce carbon emissions by up to 90 percent — can hold up to 100 passengers, 10 tons and stay in flight for five days. The company plans to enter commercial service in 2026, and already has an all-electric, heavy-lift cargo ship in the works.

Other efforts include Google-backed venture LTA Research, a California-based startup that is building a 400-foot zeppelin known as the Pathfinder 1 for humanitarian aid; and, while most projects are utilizing helium as its lifting gas of choice, the H2 Clipper is building a hydrogen-powered prototype.

Airships Could Become Unmanned

Nicolas Caeymaex, an environmental advisor who served as the project lead on the now defunct FlyWin project, sees unmanned, drone-blimp hybrids as a possible avenue for the next generation of airships.

Programmed by algorithms, these remotely piloted vehicles — like UniBlimp’s ultra-lightweight, single-engine model in the making — create a constant feedback loop using a system of integrated sensors powered by artificial intelligence.

Launching unmanned aircraft is also less risky, which is a crucial factor for contemporary airship startups that are essentially building the sector from scratch. Abiding regulations and affording certification costs proved to be one of the biggest challenges in Caeymaex’s experience.

“We don’t live in the same context as the original airship pioneers,” he said. “Today’s regulations won’t let you fly easily.” One minor change to a vessel typically results in a barrage of new tests, and if the weather conditions are not ideal for a test flight, the authorization process for a permit restarts.

Airships Will Continue to Apply New Technologies

On the bright side, this generation of airship manufacturers reap the added benefit of applying novel technologies to tried-and-true proofs of concept. Installing flexible photovoltaic panels along the envelope to power up on-board batteries and integrated sensor systems, like LiDAR that’s designed to measure lifting gas levels at all times, are a couple modifications that bring airships into the 21st century. Additionally, by using navigational technology to find and catch a jet stream, researchers estimate an airship could make it around the world in 14 to 16 days.

And even though Caeymaex is a bit skeptical of the online airship hype, he said “it would be a dream” to see Google’s Pathfinder 1 or his colleagues at Flying Whales pull it off.

“We have to try,” Caeymaex added. “Because if we don’t try, [airship aviation] will never happen again.”

Frequently Asked Questions

An airship is a steerable, vertical-lift aircraft that uses lighter-than-air gas — often helium or hydrogen — to produce lift and a propulsion system for thrust. They are also known as zeppelins, dirigibles and aerostats.

While far less popular than they were 100 years ago, airships still exist, and some companies, like Hybrid Air Vehicles, Flying Whales and LTA Research are reintroducing the lighter-than-air tech with their own contemporary twists.

Blimps are one of three types of airships. These non-rigid, balloon-like aerostats rely on internal gas pressure to maintain their form, as opposed to semi-rigid or rigid models with built-in, structural framework.

Airships, as we know them, are inefficient compared to modern transportation systems. They’re also vulnerable to bad weather conditions, expensive to build and costly to operate, with helium priced at about $100,000 for a one-way trip.

Airships can be safe when construction and operations follow modern airship safety regulations. Airship safety may be improved by using modern materials during creation, helium gas as a fuel source as well as GPS and navigation systems to avoid dangerous weather conditions during flight.

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