Airships: just full of hot air?

Ever since the Hindenburg disaster, airships have been seen as dangerous by the majority of people. Airships are are large machines made of several components attached to an envelope, a hollow structure containing a lighter-than-air gas. There are several different forms of airship, such as rigid, semi-rigid, and non-rigid body aircraft. A non-rigid-body airship’s envelope has no solid structure inside of it, like struts or ribs. Essentially, it’s just a giant balloon. Semi-rigid airships have a metal keel running along the bottom of the envelope, like a spine. This lets the airship’s gondola carry a heavier load, but is lighter than a rigid-body. The envelope of a rigid-body airship is fully supported by an interior network of metal struts, forming a grid that creates the shape of the envelope. This means that the airship can carry very heavy loads, but must be filled with more lifting gas than other types.

Although they are rarely used today, airships do have several advantages that made them a worthwhile form of transport during their heyday. First of all, they consume less fuel than either planes or helicopters, and can hover in place without using any fuel at all, thanks to their lift being passively generated by lighter-than-air gas. This means that they can stay in air far longer than any other means of air travel. This also used to let them travel over a longer distance than airplanes, making them the only way to travel over an ocean by air. However, modern planes can travel farther and faster than airships, making their range obsolete. Their fuel efficiency can still be an asset, however, in situations where an  aircraft needs to be able to stay in the air for a long time without covering a large distance. For instance, airships have found use in advertising, surveillance, and search-and-rescue. Finally, contrary to popular belief, airships are actually rather resistant to damage. Their envelopes are usually divided into separate cells, and their lifting gas isn’t under high pressure, meaning that if an airship is punctured it will lose buoyancy gradually, and can stay in the air if it has only one puncture. This means that it is very difficult for an airship to crash.

Of course, there are reasons why airships are no longer widely used. Firstly, the most well known reason is their flammability. However, most modern airships are not actually at risk of catching fire. This is because there are two gasses commonly used to fill airships’ envelopes: hydrogen and helium. Hydrogen is both widely available and the lightest element on earth. However, it is also extremely flammable; the Hindenburg, as well as many other dirigibles, was filled with hydrogen. In comparison, helium is only slightly less buoyant than hydrogen, and is not flammable, but it is also extremely rare on earth and is light enough to escape the atmosphere, making it a non-renewable resource. Currently, all airships are filled with helium, making fires a non-issue. The other two major downsides, however, are real, and stem from other forms of transport simply being better than airships in certain respects. Firstly, as mentioned above, modern airplanes can cover the same distance as airships in a fraction of the time. Secondly, helicopters are just as maneuverable as airships, while being much smaller and able to operate in rough weather, which is simply impossible for airships, due to their size.

In conclusion, while they are often viewed as dangerous, airships are actually far safer than most people assume. In particular, they are not usually flammable, and are very resistant to crashing. However, although they are fairly safe, they are outclassed by other forms of air travel in almost all respects. Because of this, I believe that they should generally not be used when other types of aircraft are available, except in a few niche situations (like advertising).