Last Wednesday a Northwest Airlines Airbus A320 overflew its intended destination airport by at least 150 miles before reversing course and proceeding inbound to land. The A320 was operating as Northwest Flight 188 with service from San Diego to Minneapolis/St. Paul (MSP). What the heck happened?
We're not sure yet. After landing the crew was interviewed by the FBI and airport police at which time they admitted they were in a heated conversation about airline policy which caused a loss of situational awareness on the flight deck. If that's true, the conversation must've been pretty darn heated because it takes a colossal episode of inattention to fly beyond the TOD (top of descent) point, then continue flying for another 250-300 miles while missing repeated calls from air traffic control. I don't fly A320s, but every modern airline jet that I know of will automatically alert the crew in some way, even if minimally, when the TOD is reached without a descent being initiated. That means the crew of Flight 188 had to ignore messages from both their aircraft and ATC for hundreds of miles.
Were both pilots asleep? Maybe. The pilots denied this during interviews, but it doesn't sound impossible to me. The aircraft's cockpit voice recorder (CVR) will be reviewed and we'll find out what really happened to cause such an extraordinary foul up.
People wonder, were the passengers at risk? Of course! No matter what the case was on the flight deck, sleeping pilots, arguing pilots, whatever, there was no one in command of that aircraft for hundreds of miles. That has all sorts of implications on flight safety. The pilots could've missed a developing mechanical problem as they were obviously not actively monitoring the aircraft's systems, a low fuel situation could've developed, the aircraft could've wandered even further off course, or any number of other dangerous situations could've developed.
Any pilot incompetent enough to allow something like this to happen is probably stupid enough to lie about it too. Luckily, the CVR will reveal the truth. More regulations are certain to be born at the conclusion of this investigation about cockpit crew conduct during cruise flight. When a couple of clowns screw up, it creates a mess and new restrictions for the rest of us, including the good guys.
