I don't believe nationalised airlines with soveriegn wealth funds and favourable taxation and accounting standards qualify as free markets. The idea of free markets is that the government stays out of them!
Getting slightly OT but to answer this, favourable taxation and accounting standards ARE what help define free markets. The same rules apply equally to all businesses operating from Singapore. Despite nothing but an island it's a thriving country based on these principles, unlike our rent-seeking welfare nation. Governments DO play a role in free markets, ideally they merely set the rules and stand back.
Saying Singapore Airlines is a nationalised airline is a bit disingenuous. For ease refer to
Singapore Airlines - Wikipedia.
The airline is a subsidiary of Singapore government investment and holding company Temasek Holdings which holds 54.5% of voting stock.
It has consistently shown via independent audits that it doesn't
receive() state funding, subsidies or preferential treatment from the government,..
Agree with the rest of your sentiments. Cheers.