There Are Backups For Snoozing Air Traffic Controller
- By Jason Paur
- March 25, 2011 |
- 8:00 am |
- Categories: Air Travel
Falling asleep on the job is pretty much a no-no anywhere. But as the air traffic controller who took a 24 minute nap late Tuesday night has found out, falling asleep at certain jobs makes national news.
As bad as it was for the person inside the tower at Reagan National Airport to take a snooze, he was just one of many air traffic controllers that an inbound airliner would have talked with on a flight to the airport near Washington D.C. that night. And as was demonstrated, there are several options for aircraft should the situation arise when there is nobody answering inside the tower. In fact many airports with control towers do not have anybody working the overnight shift and aircraft will come and go all night long on their own. Though these aren’t usually at busy commercial airline hubs.
The big commercial airlines operate on instrument flight plans and are (normally) in contact with an air traffic controller throughout the entire time the airplane is moving. A simplified overview of a typical flight involves talking to many people, all of whom are often referred to as “air traffic controllers.”
At Reagan National on Tuesday night, the pilots of two aircraft were unable to establish contact with the control tower. But the pilots were still in contact with the air traffic controllers who had been following them on radar up until their arrival at the airport. One of these controllers advised the first aircraft, an American Airlines flight from Dallas-Fort Worth, to follow the procedures for an arrival at an uncontrolled airport.
The procedures for landing at an uncontrolled airport are familiar to any pilot and are commonly used by many airlines at airports across the country. The pilots simply announce their location on the airport frequency designated for such use, and complete the landing on their own following standard patterns while keeping an eye and ear out for other aircraft. In addition to the flight from DFW, a United flight from Chicago also landed using the uncontrolled airport procedures.
Once the American Airlines flight was on the ground, the pilots were able to reach the controller in the tower who subsequently admitted to falling asleep according to a preliminary National Transportation Safety Board report.
A typical airline flight will be handed off between roughly four distinct groups of air traffic controllers: ground, tower, approach/departure and center. And within a few of these, the pilots could be handed off to several different people located in the same facility.
Air traffic controllers inside the tower at Boeing Field in Seattle.
After confirming a flight plan and receiving IFR (instrument flight rules) clearance, the pilot will typically contact a ground controller located at the airport who will handle the airplane from near the gate to a position near the runway. From there, the pilot is told to contact the tower and a person in the tower will tell the pilots when they are cleared to take off. Usually it’s only a matter of seconds after take off that the tower then hands the airplane over to departure control, or simply “departure.”
The controllers acting as departure control are located at the terminal radar approach control, or TRACON facility that handles both departures and arrivals. These facilities are usually very close to the airport they serve, but can be many miles away from smaller airports also controlled by the same people. The controllers sit in darkened rooms and monitor all of the aircraft on radar screens where the flight information, altitude and speed are displayed next to a small icon indicating the airplane’s location.
The view for an air traffic controller at the Seattle TRACON. SeaTac airport is located near the center of the picture.
Once an aircraft is handed off to departure, it is considered to be under positive control, meaning it is being followed on a radar screen at all times. Departure control only handles the aircraft for a limited amount of time within about 50 miles of the airport before handing the pilots off to an air route traffic control center, better known simply as “center.”
There are 20 center facilities in the contiguous 48 states and one each for Alaska and Hawaii. These facilities are simply known by the cities where they are based. A pilot flying from Seattle to Chicago would be handed off from Seattle Center (top picture) to Salt Lake Center to Minneapolis Center and finally to Chicago Center. These controllers also sit in darkened rooms and monitor a wide area, often handing off aircraft to another controller within the same room as an aircraft passes through a particular center’s airspace.
A map showing the 20 "center" facilities in the contiguous United States.
Once an aircraft nears its destination, the center controller will once again pass the aircraft to a TRACON facility, though it will now be handled by an approach controller, such as “Chicago approach.” The approach controller will typically handle an aircraft from inside the same 20-50 mile radius until it is able to navigate using an approach procedure for the destination airport. Once the pilots are established on the specific approach (usually when they are more or less lined up with the runway, though they could still be several miles away), the aircraft is once again handed over to the control tower. The control tower will then guide them in with a combination of radar and visual contact. Once the airplane is on the ground and off the runway, the tower hands them back to ground control which will take them to the gate.
During the nap time on Tuesday night, it was the controller in the tower who took a snooze. It’s not unusual for the overnight shift to be a single person who would handle not only the tower duties, but also the ground control duties for the small handful of aircraft landing late at night and early morning. It was the controllers in the Potomac TRACON who worked with the pilots and advised them to land using the uncontrolled airport procedures.
The napping person in the tower was a 20 year veteran who has been suspended. The NTSB is continuing their investigation of the incident.
Photos: Jason Paur / Wired.com, Map: FAA
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