To give a broader understanding of the situation:
QANTAS is having a hard time competing for international flights, especially against Asian airlines operated by our near neighbours, as they pay lower wages etc. To make that arm of the business profitable, they want to move maintenance of international flights offshore, and possibly hire pilots at lower wages from outside Australia. This is for international flights only, the domestic arm of the company is making money.
Th unions for months now have been complaining, saying they want guaranteed jobs for life, plus pay rises. So they've been striking every few weeks, disrupting people for a day or two at a time.
QANTAS won't agree to the 'job security' clauses the unions want, as they need to be able to fire people and restructure when market forces require it. Otherwise the company will go belly up and everyone loses their jobs. But the unions want their members to be 'unsackable'.
The CEO has had enough, and stopped flying so bring the issue to a head. Already the government has stepped in to resolve the situation (as we knew would happen), telling both parties to get on with working. This is in QANTAS' favour, as they retain the ability to manage their company rather than have unions run it.