Let's be clear, air traffic controllers ought to stay awake during their duty period and when they are working traffic they should assure that minimum separation is maintained.

The media has recently reported on several incidents of controllers sleeping on the job.  Always this has been accompanied by everything from low key suggestions that safety was compromised to near hysterical proclamations about the near death of all aboard.  The most egregious case I saw was on CNN where a purported expert, a former controller, attempted to link the scattered incidents of controllers napping on the job to labor unions and a supposed pro union bias by Randy Babbit, the FAA administrator.  Where do they get these clowns?

Sleeping on the job:  Well obviously that is not a good thing to do and the FAA has quite reasonably implemented procedures to improve staffing so a single incapacitated (sleeping or locked out) controller can't bring operations to a halt.  But this was not the disaster in the making that media has used to increase their ratings.

What Controllers Do:  Air traffic controllers have two primary responsibilities and a great deal of pressure to be more productive.  Their two responsibilities are to Separate and to Sequence traffic.  Separation is just what it sounds like, keep airplanes from running into each other.  Sequencing is also just what it sounds like, keep the traffic flowing smoothly as it passes through their airspace.  These are tasks you do all on your own each time you get in your car and drive to the grocery store.  That being said, the rules and procedures are incredibly complex and the pressure to move more and more traffic is outrageous at most facilities.

Asleep at DCA:  While the lone controller asleep on duty is an event that should raise concern the two inbound airline crews could have easily landed and taxied their aircraft to the gate without talking to the tower and with no reduction in air safety.  This happens safely thousands of times a day at both controlled and uncontrolled fields.  At uncontrolled fields aircraft announce their positions on a common frequency, exercise care and vigilance and sequence themselves into a standard traffic pattern.  At controlled fields it also happens all the time here is how.  Let's imagine there is only one aircraft in the area.  The controller clears the aircraft entering his airspace to fly a visual approach and clears them to land.  He might say 'make right traffic' or 'make left traffic' or 'proceed straight in' or he might just leave all that to the pilot's discretion and say 'cleared the visual approach, cleared to land.'  In all those situations when the pilot accepts that clearance he just accepted responsibility for separating himself from other traffic.  The next aircraft to enter might be told to report the first aircraft in sight, and when the pilot does so he is cleared the visual approach and cleared to land. He too has accepted responsibility for separation and this time he has to be sure to keep adequate spacing between himself and the traffic he is following.  As you can see the only thing the controller did was sequence the traffic, tell them who goes first.  With only two aircraft in the air the flights could have easily done this on their own just by talking to each other.

The reason the sleeping controller was a problem that night at DCA is not that there was any danger to either of the aircraft, it is because the law does not allow a pilot to land at a controlled field unless he receives a clearance to do so.  Put another way the pilots could not land because the regulations did not allow it even though it was objectively safe to do so.  So, absent an emergency, the pilots have to go to plan B and head to an alternate.

Loss of Wake Separation:  This was a potentially more serious situation.  But the fact is that there was no danger of collision.  The danger was of a possible wake turbulence encounter.  Wake turbulence encounters can be very serious and it is possible that the First Lady's aircraft would have been knocked about pretty badly if it actually flew through the wake, but it seems very unlikely that this was going to happen.  Three miles is the normal separation criteria and they up it to five miles if the preceding aircraft is a "heavy."  But some heavy aircraft make very little wake, or their wake dissipates quickly, while other aircraft, the Boeing 757 comes to mind, causes serious wake turbulence even when it is 'light.'  So it is too early to tell what really went on.

The Air Ambulance Flight:  This is the only flight where the controller error, sleeping on the job, was likely to hurt someone.  In this case the patient was pretty ill (that's why they use an air ambulance) and the delay incurred in diverting to an alternate may have been detrimental.  But, the pilot still had an ace up his sleeve.  He could declare an emergency and land even though there was no landing clearance.  When a pilot declares an emergency the regulations are subservient to the situation and the pilot can land without a clearance.  A passenger about to die is undoubtedly an emergency and so the pilot could have exercised his command authority in an emergency situation to land despite the controller's lack of consciousness.