Those of us who can remember 1989 will recall the effect that the lack of air travel had on the entire economy, not just the tourism sector. Airlines are a necessary part of modern life and whilst behind electricity, running water, food delivery and telecommunications, they are still well up on the list. For regional areas they are definitely an essential service.
A period of government administration for the airlines is certainly on the cards. Fares will be regulated and employees terms and conditions laid down rather then negotiated. Expect a skeleton service to be maintained, with pilots rostered simply to maintain recency in anticipation of a gradual ramp up.
The recovery from all this will be similar to that from a major war.