On twitter there is an AA pilot with a following of over 4000, who posts comments, pictures, etc. (see @Chris_Manno)
Recently he posted a picture of a mug of coffee, and even showed that the BIG planes' cockpits have cup holders for this.
https://t.co/VwLU9Acawy
My question to him was whether an accidental spill on all those instruments and electronics will not be a problem, and he sort of brushed off my question with "Beverages have been on the flight deck for the last 50 years. Have you heard of any problems?"
Does anyone have a serious and more informative answer to this?