What are the main problems associated with the airplane carts?
If you're serious about this project you need to consider the views from various groups....In no particular order:-
1) The customer (i.e the passenger)
2) The service provider (i.e. the airline)
3) The airline's employees (e.g. the cabin crew)
4) The airline's suppliers (e.g. caterers)
5) The safety regulators (e.g. CAA/FAA)
Good luck!