Is it permissible to work as an inspector to ensure that aircraft meal boxes are free of prohibited items, with the possibility of alcohol and pork being present in them, without touching or carrying them, but merely by observing and confirming their placement in the truck?

There is no impediment to the aforementioned work as long as the worker is not involved in carrying alcohol and pork, but rather the work is in monitoring boxes and ensuring they are free from what was mentioned. The basis of the work is permissible, and it does not appear to involve direct or intended assistance with alcohol and pork. The worker's job is primarily focused on ensuring that luggage and the like are free from explosives. What is placed in terms of alcohol and pork is not the intended object of the work, and the one who places it bears its sin.