Just to add to this, I work on an enterprise sized project and we use UML all the time! Its not Boeing, but its a large code base and things get complicated fast. We make class diagrams for all of our large features. If there is complex workflows, we usually make a sequence diagram or some sort of state diagram, depends on the developer. It helps with estimating and helps flush out requirements. I can't image working without UML diagrams.

I`ve also done class diagrams for smaller projects when refactoring. It makes it easier to explain to coworkers what logic needs to go where.