It’s a weird word. That’s if you have not come across it before. How it’s used depends a lot on the context. Conspicuity isn’t everyday langauage.
One way to picture this word is to imagine a cyclist on a busy but poorly lit road. This is a case every driver has observed, I’m sure. Let’s consider two distinct cases. One where the cyclist is wearing dark cloths and riding without lights. The other case is where the cyclist is wearing a luminous jacket and is riding with lights. No prizes for guessing which one is the most conspicuous. Not only that, but the one who is less likely to be involved in an accident.
This is a simple two-dimensional space where two vehicles, or more, share a road. Both have a right to be there. However, one road user is much more vulnerable than the other. Being noticed, being seen, is key to a rider’s safety. Not a guarantee of safety. A necessary consideration, if not a mandatory one. Both driver and rider need to see each other for there to be safe operation.
In aviation the situation gets a whole lot more complex. For a start flying objects move in three-dimensional space and at speeds that can differ dramatically. From a static ballon to a fast military jet. Yet, just like driving on the roads the most basic way of avoiding collisions is to see and avoid. Naturally, there are a whole collection of rules of the air that wrap around that requirement. These rules set-up expectations that pilots will behave in predicable ways.
As technology has developed so the reliance on see and avoid has changed. Recently, I have found this is happening on the roads too. Sensors on my new car provide an autobraking function that kicks in when approaching a slower moving vehicle ahead. There’s a tracking function that nudges the steering wheel when drifting across a white line. Both forms of safety automation can be deselected. Do they result in fewer collisions? I don’t know.
There’s another aspect of flying that is an obvious difference from life on the roads. When collisions happen those involved are not going to stay put. Gravity will do its job. If an impact is sufficiently severe then it’s highly likely that one or more aircraft will not be flyable. An incident turns quickly into a catastrophe.
Thus, in aviation it’s vital that not only does each pilot need to know where they are but they need to know about everything around them. The condition of being conspicuous is not optional. It’s best if aircraft are easy to see. Surprisingly, this is far from always being the case. Unlike the lines on the roads, paths in the air crisscross and aircraft can be above and below one another. The geometry involved can get extremely complicated.
In the 1920s, innovations in Croydon[1] led to the world’s first air traffic control system. A growing amount of air traffic meant that a means had to be found to regulate their use of the air space. This was possible because an electronic means of aircraft communication had become viable.
The subject of Electronic Conspicuity[2] has come on in leaps and bound ever since. Finding ways of sharing awareness of everyone’s situation has made aviation safer. Radar and aircraft transponders are an integral part of commercial flying. This story doesn’t stop. I could go as far as to say that this whole subject is still in its infancy. With ever more airspace users demanding access then innovations continue to be absolutely vital.
[1] https://www.flightglobal.com/ops-safety/2020/02/colourised-images-mark-centenary-of-worlds-first-control-tower/
[2] https://www.caa.co.uk/General-aviation/Aircraft-ownership-and-maintenance/Electronic-Conspicuity-devices/
John Vincent 