The science of airships has been around since Karith's birth as a nation, but has always been jealously guarded by that city's elite. Even today, remarkably few outside the floating monolith know how to construct one of these flying machines, and even fewer know how to outfit them with weapons. We can thanks the international agreement for the demilitarization of airborne vessels (better known as DAV) for that last one; but, as my own career has taught me, you can't really stop criminals without using lethal punishments. Barring that, you can only teach them new tricks, so DAV was more of a roadblock than an impassable wall.
See when Karith locked down their secrets so effectively, they were issuing a challenge to me. How could I not take a peek, especially with so many lucrative bidders? So I stole it from them. I stole a copy of the basics of airship construction and history, as summarized below.
Airship construction, at least as far as the exteriors are concerned, varies widely based on the wealth of the creator and what materials they have available. There are no real requirements for the hull in terms of specific materials, but obviously something made out of wood is going to be very brittle compared to metal and aerodynamics should always be respected. What's really important, the thing that allows these ships to fly, is the infrastructure.
The innards of an airship are a complicated mass of magical enhancing, magical reducing and magical conducting materials. Typically, the extremities of a ship will take power from a well-guarded core at the vessel's center, especially with classical models. The energy of this core then passes via field or circuit to every implement on the ship, bringing them to life while also allowing the thing to fly.
The core itself is a massive, magical vortex of energy kept in check by wards, hard materials, and magically resistant fields. Unfortunately, all cores are also inherently unstable. They can explode violently if tampered with; and this is why they are usually the most guarded portion of a ship, more so than the cockpit. Understandably, this means that the current, most pressing issue among airship engineers is finding alternatives to the "classical" design. Sadly, safety has been proven directly proportional to cost in this manner. Every design possible has some sort of drawback, and the perfect ship appears to be an impossible dream.
Limitations and History:
All airships have some form of limitation, whether that be in terms of flight speed, the altitudes they can reach or the terrain they can traverse. Most of those limitations are important to prospective buyers, because a more able ship will obviously be more expensive, but, to most who are interested in these plans, the chief limitation of concern is in regard to airship weaponry.
According to Karith researchers, the original airships were in fact designed to be weapons of war. They were outfitted with various spell "pads" and casting engines disguised to look more like decorative symbols than canons, and each was capable of casting spells that the pilot personally knew up until the energy reserves for weaponry were depleted. After depletion occurred, there was also a lengthy recharge time because of the fact that the spell canons themselves were too vast to be powered by any one mage, no matter how powerful they were, and so needed their own energy reserves. Additionally, there was almost always a safety mechanism implemented to prevent drawing power from other systems that kept the ship afloat in order to reuse weapons on an empty reserve. For these reasons, most of the earliest ancestors of modern day airships were powerful, hit and run weapons meant to get in and out of an area without sticking around for a siege. They were simply never meant to be used as siege weapons.
The original weapon engineers also ran into issues pertaining to the size of these weapons. No matter how well their technology performed on the ship, engineers and pilots could never take that next step to create handheld canons. Technology of that sort was proven to be a fable early on in the design process of the technology, impossible to create even in field airships. Those who tried frequently destroyed themselves outright along with their ship, provided the miniature canon didn't just short out when they tried to use it. The machinery was just too complex, and nowadays there is a well known critical mass point among airship engineers that dictates a size to power ratio. The smaller an implement gets, the less power it can utilize from the ship without losing effectiveness as a weapon. Handhelds, or anything that could possibly be lifted inside of an airship, are simply too small to the point that they cannot hold any type of charge capable of being weaponized: a fact that seems to have come as a great disappointment to the old Karith engineers. This fact is still true today.
As an addendum, weapons of this sort also appear to rely on the cores mentioned earlier, or some equally volatile and powerful source. Sources of that level can only be contained with technology on par with an airship, and are not portable; so don't get any funny ideas about trying to set up ground, spell canons. You'll only blow yourself up.
Limitations and construction guidelines for modern airships are the same as they were at the technology's inception (i.e. as listed above). It is actually remarkable how little has changed over the years for them, and yet there are still masterful artisans in this world who remain on the cutting edge of airship technology. For example, the classical approach of airship construction was to have huge crews of engineers to build and pilot them. Those crews made airships particularly expensive, more so than they are today; but more modern airships have started to automate most of the functionality that required crews. Nowadays, the regular, personal airships that most rich people buy from Karith only require a single pilot and can get by without a crew. Even war airships, with their typically massive size, only need a crew of about ten, magical engineers to maintain the systems, and those engineers need not be actual people. There are rumors that some of the less reputable ships use automatons to keep themselves in top shape, so for everything that hasn't changed there is actually quite a bit that has. Efficiency has grown.
As for war airships, well, I anticipate they'll start popping up again soon enough. Although, anyone building those monstrosities will have to do it well off the radar and with less than reputable crews. It is theoretically possible to construct an airship on your own of that caliber provided you have the materials, knowledge and several decades to waste; but, according to these documents, that's not very advisable.
Those are just the basics. Of course, if you want to have the actual plans, you'll have to pay me... handsomely.
-The Pale Wolf