With the recent crisis and grounding of so many aircraft and crews having to stand down, when commercial flights do start to resume, will crew just be able to start again just as they left off or will there have to be some sort of cognitive retraining?
Yes, but not just on an individual level.
It’s not uncommon for pilots to have several years off during the middle of a career, due medical reasons, loss of employment or just a desired sabbatical for whatever reason. When returning to their flying job however they are going back via a training system and comprised of instructors, both simulator and flying, who have maintained total recency with the current environment and procedures, and their first few months will be with line crew who as well haven’t had years off work so they’re cognitively quite sharp.
With the groundings of entire fleets and airlines, for a period of some which may be years, you have a unique situation where all pilots, line and training, in that airline or fleet haven’t been operational for that time. And in the intervening time have been focusing their brains not on aviation but other pursuits.
The upcoming situation when large groups of pilots return to the air all at once after considerable time off will produce challenges that aviation safety systems will need to mitigate.