Currently, with new space DLC, there is a system of air pressure and if someone flies too high up, there's no air to breathe unless the craft is sealed. But, as you may know, most of planes in Stormworks are not sealed and, therefore, cannot go high up, which is not very realistic, since irl modern planes are sealed and oxygen goes to the pilot through the mask which is the improvement I'm suggesting: make pilot mask partially function like space suit and conume oxygen from a node in the pilot seat. This will make planes able to go higher without the pilot inide taking damage.