It's not unusual for infrastructure stocks to look like they are paying out unsustainable div yields and trading at ridiculously high PE ratios. It's a result of having a very expensive asset with high debt load and high interest and D&A charges but a very high cash flow due to low operating costs once the asset is completed.
The important thing to do is protect against a rise in interest rates and forex swings, which SYD have done through hedging.
So the dividends should be sustainable in the near term, although the rate of dividend growth probably isn't. As you said, there is only so much you can do to increase the profitability of a fixed asset like an airport. Even if they get the rights to the second airport they still would need to build the thing which would entail another massive debt load.
SYD Price at posting:
$6.40 Sentiment: Hold Disclosure: Held
