I write and have written for Aviation Week, Business & Commercial Aviation, and Airways magazines for a few years. Much of this duplicates what is already on the website, but in a different format. Many of the articles are unique to the magazines. The categories (human factors, operations, safety) are often picked by the magazine. When you get right down to it, it is all safety.
Human Factors
The articles dealing with us humans, mostly Crew Resource Management (CRM), leadership, management, and training.
Operations
Aviating, navigating, communicating, and maintaining.
Safety
Just about everything that has to do with safety that isn't covered in human factors or operations.