I find pain to be a bit of a, well, pain. But it's admittedly pretty useful for telling me when I'm hurt. Now engineers are developing aircraft with a similar warning system.
Spraying on tens of thousands of micro-sensors can give planes a kind of skin that allows them to 'feel' problems even before they occur. The coating could also measure things such as wind speed, temperature and strain.
As planes become smarter, I wonder if we should feel bad about inflicting pain on them?