Generally aircraft as a Super fund is not a good move, because when a quick sale is required they are worth a fraction of what they are in good times. I have seen $180-$200K B58's being offered $50K.
They also cost money to maintain and park if not in use.
This with fixed calendar life items including engines and props and even a sudden AD (the C441 life caught a few out), make for a very high risk retirement portfolio.