How often are the tires on a typical 747(say)changed..Are these tires a different grade rubber?

Question

How often are the tires on a typical 747(say)changed..Are these tires a different grade rubber?

Answer 1

When they need to be.  Each flight one of the pilots checks the tires as part of the preflight, if the tires are worn beyond limits the mechanics will replace the tire.

Airplane tires have wear threads, so when the tires is worn to the threads (where you can see the threads or see the pattern of the threads) they replace it.  If there are huge cuts or gouges in the tire it will be replaced.

Answer 2

every aircraft before flight is inspected and if a problem is seen than it is fixed before takeoff and about the rubber thing idk