Challenges in aviation security: How will it emerge from a sequence of crises?

The aviation sector is widely identified as having been acutely wounded by the Covid-19 virus, albeit this is far from the only challenge it has faced. Commercial uncertainty as a result of Brexit is one issue, the 737 MAX scandal is another, while the dangers of cyber threats to aircraft remain very real and terrorist threats ever present. In all this what has been happening in airport security? How have airlines and airports worked together, or have they? What have been the key lessons lear...