What are the most effective airport management principles for different types and sizes of airports?

Indeed 👍 Smaller size Airports have dual role to play. On one side they have to provision for every infrastructure needed for meeting the regulatory requirements and right ambeince & customised comforts to the traveller,on the other. In a developing economy, these small town airports,play a vital role in creating the logistical support and connectivity for local business to thrive and grow. Besides, it's these small towns, who are going to provide remote market, and opportunities to the airlines, expand their business to the less treaded areas, having untapped potential, with relatively less competition.

Actually I do not know whether to agree or not but surely successful flight operation in an area contributes to become a measure of progress there. Viability of an airport is subject to it's location which should be convenient for the locals as well as it should become first choice to travel. Time saved and compatitive cost of travel will matter in its success. As far as facilitation is considered it can be left to develop with the build up of travel demand. Let initial costs of airport infrastructure be just sufficient to have operations. Not being hubs business activity cannot be expected to be paying.

this is the type of airport that is bound to grow in the future as large airports are now saturated and the large aircrafts are retiring and the new fleet is adapted to medium sized aircrafts.

I believe Big does not have to mean complex and costly which is what you find with many cities' international airports. Having traversed through many- more than 30 airports in the world, both as a passenger and an operator user; I now generally choose a small to medium airport to traverse through. Why? efficiency, customer centric. One thing I have found about Big airports have rigid design that do not differentiate the needs of the diverse clients in different users categories.For instanc, they could have different sections/terminals tailored experience designs, operational output scalable to different market demands etc. Technology is playing a big part in efficiency e.g DXB airport has one of best passenger throughput efficiency

Whatever the size though it is relevant to look at an airport as a place where you would like to be without or without aircrafts. As strange as this statement might seem I just would like to share the example of Singapore which has absolutely understood that the airport is a lot more than an airport and families friends go there to visit it and spend some time and spend money obviously. The ground part of travelling has become very cumbersome as most large airports are reaching their saturation levels (which the pandemic only delayed by a few years though it was announced much before that 2022-2023 would saturation in many places) : just to get there can become complicated lately and once there massive queues are becoming the norm.

Airports should start getting inspiration from the most recently developed train stations: Saint Pancras in London - Saint Lazare in Paris. Make them part of the city- a place where you want to meet gather shop and live whether you are travelling or not. This should also make it sustainable in the long term if one can get there by train subway tram bus or even bikes!