Here are a couple links:
http://www.cntraveler.com/story/virg...t-tsa-precheck
http://www.theverge.com/2017/1/27/14...tlantic-spirit

Nothing more than saying Emirates and ten other airlines are now part of pre-check. Always nice to make more use of Global Entry although the times I've been in and out of IAD both immigration and security have almost been ghost towns.