This is a perennial, nigh eternal question. For example, see Litchfield and Allen’s 1945 book, *WHY?— Why Has America No Rigid Airships?”. At first glance, rigid airships (lighter than air flying machines with a rigid frame and separate internal lifting gas bags, as opposed to “blimps”, where the gas directly inflates the envelope like a balloon), seem to be attractive for some missions such as carrying heavy cargo to remote locations and ocean patrol, where staying aloft for long periods of time consumes no fuel. Further, the cube-square law means that for airships, “the bigger the better”—since structural weight, aerodynamic drag, and construction cost scale as the square of the linear size while volume and thus lifting capacity increase as its cube, as airship size increases, its cargo carrying capacity and efficiency grow rapidly.
Large rigid airships largely went out of fashion after both large U.S. Navy Akron-class airships were lost in the 1930s in crashes killing a total of 75 people, not to mention the unpleasantness at Lakehurst, New Jersey in 1937.
But still, plans for large rigid airships bubble up from time to time, for applications as varied as luxury tourism to super-heavy cargo delivery to and from remote locations. Some of the challenges they face are discussed in the video. Those who envision large fleets of enormous airships will probably have to come to terms with using hydrogen as a lifting gas, since helium, although the second most common element in the universe, is scarce on the Earth, expensive in large quantities, and far too costly to vent to the atmosphere when a ship needs to reduce its buoyancy. Hydrogen is cheap, provides more lift than helium, and can be made on board when needed, for example by reacting sulfurinc acid with iron filings, but has the obvious disadvantages. Still, with supposedly serious aircraft manufacturers proposing hydrogen fuel for airliners to reach their “net zero” goal by 2050 and a vast hydrogen production, storage, and transportation infrastructure to support it, the additional caution needed to use it for airships seems modest by comparison.
Much more serious, and little discussed in the video, is the weather. Imagine what a structure three hundred metres long (as proposed for some cargo airships: the Hindenburg was 245 metres in length) does when confronted by high winds, wind shear, gust loads smaller than its structure, or rapid changes in wind direction when maneuvering in the vicinity of ground facilities. There’s no reason to wonder—just look at the sorry record of airship accidents due to these conditions. Now, airship advocates observe correctly that present-day monitoring of weather conditions, both from satellites and ground-based radar and weather stations, and the reliability of short-term predictions from these data allow avoiding most of the the dangerous conditions that brought down airships during their heyday, but most is not all, and a large fleet is certain to encounter hazardous conditions that cannot be avoided in time. And suppose a storm is approaching—where does an airship larger than three football fields take shelter? Will a fleet of thousands of airships have tens of thousands of gargantuan hangars spread across the world? If all of the countryside is covered by airship hangars, where will they build the forests of bird-choppers? And where will the silver ships of the sky take shelter in mid-ocean?
