How Does Aa Handle Cultural Diversity,non-verbal & Written Communication?

You can read the American Airlines' Diversity and Inclusion: A Way of Life at American Airlines in which you will find In-language marketing, promotions and communications; International and in-language web presence.  Under Deliver Product Travel/Service you will see Multi-language personnel in reservations, at the airport, onboard aircraft.  You will also see In-language sinage and inflight entertainment.

Tomas W Horton, Chairman, President and CEO,AMR Corp and American Airlines has stated: "American is more than an airline. We are a global company that connects people from many different cultures and communities. For us, diversity and inclusion aren't just inspirational goals. That's just the way we do business."

In February 2011, Michael Collins, Managing Director of Diversity Strategies at American Airlines wrote: Each customer, client, and employee brings a unique perspective that allows us to solve problems, overcome challenges and implement new ideas. At American Airlines, we promote inclusion for all and strive to create an environment where all differences are valued. American uses a combination of third-party partners, newly-formed external advisory councils, our employees, and relationships with key advocacy organizations to gain greater insights into how to deliver the best travel experience possible"

Your question, of course, is how they do this.  You should be able to get some insight in this linked American Airlines video.

Yes, there are probably areas which need improvement. On the linked page to American Airlines online form for International Passenger Information, you will see a drop down menu when you open English on the top row of tabs. From that tab you can select a country and a language for the form. I was surprised that some languages were not available choices but perhaps there is a technical reason, an oversight or a decision.

If you go to the Worldwide Reservations Phone Numbers page at American Airlines, you will see a chart for non-English speakers within the United States which includes, Japanese, Mandarin, Spanish and of course TDD (hearing and speech impaired).  

Remember that airlines have affiliates, alliances and codeshare partners who might also fill a niche in cultural diversity. American Airlines has several alliances, affiliates and partners.