welcome back. the faa is taking action after an air traffic control center in the washington, d.c. area recorded its 22nd dangerous mistake last week. now, wednesday the faa sent a team of experts to the warrenton center that controls all flights in the greater d.c. area. the latest controller mistake involved a united airline airbus that narrowly avoided colliding with a business jet. that happened on june 28th. nbc's tom costello covers aviation. he joins us now. 22nd dangerous mistake recorded. what is the problem? >> well, that is not a simple easy answer. we're talking about in the most recent case an airbus a-319 from chicago inbound landing at reagan national airport and came