How better to maintain the status quo with the union and possibly get more for your members.

First, get government to take a stake under the guise that they're bailing everyone out to save jobs.
Then, use votes of union membership as a neogitating tactic to influence the operation of the airline to your advantage by influencing the politicians who inevitably meddle in the management of that airline due to the government taking a stake.
Run airline into ground, get government to pour more public funds in to keep it in the air, and continue to support a business model that doesn't work.