"When asked about ORD (O'Hare) controllers' awareness
of the need for adequate sleep, one supervisor stated that
controllers did not discuss the issue much and were 'just used to
being tired.'"
Source: John Clark, NTSB aviation safety
director, in the May 16 letter to FAA Chief Operating Officer
Russell Chew regarding a possible link between a series of runway
incursion incidents at Chicago's O'Hare International Airport this
year... and controller fatigue.