Fatigue
The following is extracted from an article titled “The Runway and You” by Ian Wigmore, published in Eurocontrol’s “Hindsight No 6”, January 2008 pp. 22-24.
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“Seatle/Tacoma International Airport, July 8, 2001
A controller issued a taxi clearance to a Boeing MD-80 to cross a runway 34R at the same time that a Boeing 767 was on short finals to the same runway. The pilots in the landing aircraft reported applying maximum braking to avoid a collision with the crossing aircraft, and the 767 stopped only 810 feet short of the MD-80. On the night of the incident, the controller was working his third shift in 2 days, with an 8-hour rest period between shifts. The day before the incident, he had worked from 1400 to 2200, slept between 4 and 5 hours at home, worked from 0555 to 1355 the day of the incident, slept 3 hours at home and then returned to work the incident shift, which began at 2245. The controller stated that he tried to avoid midnight shifts whenever possible because of fatigue; at the time of the incident he was feeling tired, in part because he knew he “… had to be up all night long on a double quick turn around.”
Denver International Airport, September 25, 2001
A Boeing 757 departed runway 08 in night-time VMC. Runway 08 had been closed because of construction workers and equipment operating near its departure end and, during takeoff, the aircraft passed within 32 feet of lights that had been erected to illuminate the construction area. The controller handling the 757 was aware of the runway closure and had instructed the crew to taxi to a different runway. However, after the crew requested takeoff on runway 08, the controller agreed and instructed the crew to taxi and takeoff from the closed runway. The controller had worked a shift at the tower from 0530 until 1330 the day before the incident and then had a 9 hour rest period during which she obtained between 60 and 90 minutes of sleep. She then returned to work the incident shift, which began at 2230. When asked why the incident occurred, the controller stated that she was “… probably tired, not alert enough.”
LOS ANGELES INTERNATIONAL AIRPORT, AUGUST 19, 2004
A controller cleared a Boeing 737 to taxi onto and take off from runway 24L at the same time that a Boeing 747 had been cleared to land on the same runway and was on a short finals. The pilots in the landing aircraft saw the 737 taxi onto the runway and discontinued their approach about 12 seconds before the impending collision would have occurred, passing approximately 200 feet above the 737 during the go-around. The controller had worked a shift the previous evening from 1530 until 2330, then went home and slept between 5 and 6 hours before returning to work the incident shift, which began at 0730.The controller described the portion of his shift before the incident as a “hard day’ and attributed his error, in part, to fatigue.
CHICAGO OHARE
INTERNATIONAL AIRPORT, MARCH 23, 2006
A controller cleared an Airbus A320 to cross runway 4L and, less than 15 seconds later, cleared a Boeing 737 to take off on the same runway. The pilots in the departing 737 observed the A320 moving toward the runway, rejected the takeoff, and stopped before reaching the taxiway intersection where the A320 was to cross. The controller had worked an 8-hour shift the previous day until 2130 and was then off duty for 9 hours. Because of commuting and personal activities, he slept only about 4 hours before returning to work for the incident shift, which began at 0630. He reported that he felt “semi-rested” during his shift but was “not as sharp as he could have been.” He stated that the second shift had been a quick turnaround with “no coffee.”
The effects of fatigue on controller performance have been under study in USA for many years, and the issue was raised again following the fatal accident involving a Comair CRJ-100 which crashed while attempting to take off from the wrong runway at Lexington Blue Grass airport on August 27, 2006. During its investigation, the NTSB learned that the air traffic controller who cleared the accident aircraft for takeoff had worked a shift from 0630 to 1430 the day before the accident, then returned 9 hours later to work the accident shift from 2330 until the time of the accident at 0607 the next morning. The controller stated that his only sleep in the 24 hours before the accident was a 2-hour nap the previous afternoon between these two shifts. In its final report on this accident, the NTSB concluded that the controller did not detect the flight crew’s attempt to take off on the wrong runway because, instead of monitoring the airplane’s departure, he performed a lower-priority administrative task that could have waited until he transferred responsibility for the airplane to the next ATC facility. The extent to which fatigue was a factor in the controller’s decision could not be established.”
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Typical turnarounds on the current Dublin roster include
1400-2230/0830-1800 or
1400-2230/0700-1400
and night duties are preceded as follows,
0630-1400/2330-0700 or
0600-1400/2330-0700.
These duties are part of a 5/3 roster.
One of the recent proposed rosters (6/3, 6/3, 7/2 sequence) included a turnaround of 0600-1200/2130-0800.
Draw your own conclusions.
Yours.
FoxyTotty 
Last edited by FoxyTotty; 23rd Feb 2008 at 09:41.