Flynn was arguably McChrystal's most important partner in building JSOC's network. "We once had a problem in terms of how we were going to track our units on the ground using satellite technology. It's almost unthinkable today because of GPS, Blue Force Tracker and so forth," recalls Andrew Exum, now a senior fellow at the Center for a New American Security, referring to a GPS receiver system that allows U.S. troops to track the movements of their allies. "I remember Gen. Flynn's solution was to track down a really smart engineer at Georgia Tech University, who developed a piece of software for use by commercial aircraft. It went outside the standard Army acquisition process – we'd still be waiting for the equivalent of Navstar if [Flynn] hadn't. But the fact that he was comfortable interacting in the world outside of the military in order to achieve an effect says a lot about him."
DARPA McChrystal relied heavily on Flynn
https://www.wired.com/2011/09/mcchrystal-network/
Charlie and Mike Flynn worked closely with McChrystal Staff.
The two brothers have more in common than simply holding some of the highest offices in the US military, though. Both are graduates of the ROTC program at URI and both have served extensive tours in Afghanistan and Iraq. The two also worked very closely together on the staff of retired four-star general Stanley McChrystal—the previous commander of Coalition Forces in Afghanistan. Michael served as his Director of Intelligence, while Charlie—then a colonel—served as his Executive Officer.
Charlie calls McChrystal one of his most respected mentors, and attributes much of his career’s success to the guidance provided by the retired General. Charlie was put under commander McChrystal at a young age, a “sweet spot” as he calls it, “the time when you’re deciding whether or not you want to go for the career.”
https://www.golocalprov.com/news/two-ri-brothers-two-usa-generals