Robert Gates, U.S. Secretary of Defense, fired U.S. Air Force's military and civilian chiefs for a series of mishaps related to nuclear weapons in the Air Force's custody. The most serious, of course, was the incident at the Minot Air Force base in August 2007.
This goes a step further that firing of colonel-rank commanders in November 2007, which followed the initial investigation of the incident. It not surprising that that first set of measures failed to change anything. I wrote at the time that
... the incident at Minot is a sign of a deeper process and that short of starting a new Cold War, no amount of organizational change could provide the military with the sense of mission required to handle nuclear weapons with the attention they deserve.
This is more or less what we see today. Hans Kristensen reported that the Air Force did not even properly registered the Minot incident in its database. And just last Sunday, the 5th Bomb Wing at Minot Air Base failed to pass a nuclear inspection.
I doubt that the current change of Air Force's leadership would change anything as well. There is a better choice and it is still available - remove nuclear weapons from the Air Force.