Jetstar has a pretty low cASK and it is likely as low as it can go without any fundamental change in the model. As mentioned previously - LCC's can't yield up unless they're the only operator on a particular market and there is demand on that market that isn't driven by leisure. Jerstar does a good of capturing yield via ancillary revenue. I think they're pushing the $30 per person mark from the different materials I have seen on the internet. That's pretty good globally with the best airline in the world (Spirit in the US) pushing USD$45 per passenger.
Leisure demand is inelastic so it is a precarious seesaw of pricing flex for JQ. What matters most is that JQ drives an enviable EBITDAR margin. This is what matters. This is the cash. The rest (minus lease costs) is just for accounting purposes, and the current operating margin is good. Contribution earnings to the QF Group as a whole isn't so much as important as the ability for JQ to generate strong cash flow. Now, is JQ being supported by Qantas in different areas where it is appropriate to? Yes. As it should. It is a group company and the group should take advantage of opportunities to spread cost, leverage scale, and muscle capability to support each other (but not at the risk of another). If JQ was a stand-alone company the results would be different. We know this. But it would still be making money. It has strong market share and provides for the other portion of the market. It would be profitable on its own if it was. The only issues is that the is a capacity limit in Australia due to our low population and consistency in competition. When growth stops, and fixed costs cannot be spread further, and you get cASK creep - margins are eroded, with the only option to increase fares, which doesn't work.