After every flight a plane changes its oil
At least twice a year.
There are several different oils used in an airplane. Engine oil, fuel oil, hydraulic oil etc.
Yes, dealerships do oil changes. However, they often take longer than fast oil change places, and they are frequently more expensive as well.
Once a year or every 50 hours of use.
Change the oil/filter every 5,000 miles if you use conventional oil, and every 8,000 miles if you use synthetic.
Level should remain fairly constant. oil changes 3-5k mi. If you are losing oil, that is a sign of wear.
Most use Synthetic Oil.
Yes, you can take an empty oil can on an airplane. The oil can must be cleaned and can not have any residue in the can. The residue can be cleaned by using hot soapy water.
If oil changes were kept up, never
This website has the recomendations for all fluid changes. smg.toyotapartsandservice.com/index.php
oilcan fuel
To pump oil around the engine where it is needed.