Current economics are based on the notion that fuel is expensive and therefore you try to fly huge planes with lots of people because it delivers better fuel economy. This completely dominates everything in the aviation industry currently from design, logistics, to operations. The economies are such that you only fly routes where you can fill all the seats and still pay for the fuel. With electric your energy cost is a much less significant. Your main cost shift to infrastructure, cost, maintenance, etc. of the plane. If electric cars are an indication, you can expect some reduced cost there as well.
So, suddenly, flying short hops with small air planes becomes cheap and feasible. So, why fly short hops with a few huge planes that cost tens of millions and burn tons of fuel when you can fly the same route with many smaller planes that you charge using solar/wind/etc. for a fraction of the cost? Changes the game completely. E.g. London-Amsterdam could be dozens/hundreds of 6-12 seater electrical planes instead of a handful of airbuses flying back and forth. Also, London City suddenly becomes more attractive because small electric planes are not so noisy.
Basically on board staff becomes the limiting factor, not fuel cost. Now add autonomous flying to the mix and you solve that as well.
If air traffic scales down to flights 1/10 the size of today, 10 times as many takeoffs and landings are needed to move the same number of people.
I don't think we have any way to get 10x the airport capacity?
Problems with lots of small planes:
* They fly like a roller-coaster (4 seaters are crazy scary for many people).
* More crashes - bad "optics"
* Number of pilots required
They do have the potential to have more direct routes, and very short hops, with less security overheads. Maybe run more regularly, but not much of an advantage because most people want to travel at particular times of the day (same problem with buses).
As long as they don't all need 2 pilots. I'd really like to see self-driving planes, must be easier than self-driving cars surely? (And, yes, I would fly in one)
A plane has to find a way of landing safely first. I am not versed enough in aeronautics to even begin to understand how hard it is to reach human-level in mayday situations.
The issue I think is that airplane autopilots rely significantly on sensors which occasionally fail. That means self-flying planes must be able to cope with sensor failures which generally means falling back to visual cues. Self-driving cars that rely just on cameras (rather than LIDAR) are a point of debate regarding their feasibility. Planes that would have to rely on just cameras likely have the same issues.
I wouldn't, if it was made by Boeing. Just look at how badly they fucked up something as simple as their MCAS system, making it only use input from a single sensor. That kind of incompetence isn't going to yield a safe plane that flies by itself.
There are many smaller airports in and around London that you can go to with a smaller plane and quite a few that are more convenient to get to from inside the city. If noise and pollution stop being concerns, many of those would be able to absorb the traffic and building more would be a lot less controversial.