Originally Posted by
aeroengineer
So how well is the air filtered on the typical airliner? Getting the flying public confident in flying again means they have to believe that they're not inhaling a bunch of potential pathogens. Of course people packed shoulder to shoulder doesn't help in the prevention of spreading germs either. I suspect there will be a fundamental paradigm shift in this area going forward.
The duct and filter installation is very good on a brand new airplane. The filters get changed after there is about an inch dust on them. All the ducting is ripped apart at overhaul and haphazardly reinstalled. After a decade they are really nasty inside. This was back when the airlines did their own work in house. The South American shops that everyone use now are surely better!