At risk of reinventing a wheel I'm not aware of ... What about just mandating that they all pay some fraction of revenues into a common insurance fund that pay

At risk of reinventing a wheel I'm not aware of ... What about just mandating that they all pay some fraction of revenues into a common insurance fund that pays out "holding pattern" costs (furlough wages, hangar rental, etc) in times of travel-restricting emergencies. That way, no airline could gain a competitive advantage by running with a dangerously fragile buffer.