The airplane landed wheels up and slid 6,850 feet before coming to rest in grass about 140 feet left of the runway centerline. The cabin began to fill with smoke, and the airplane was evacuated. Investigation showed that because the captain had omitted the 'Hydraulics' item on the in-range checklist and the first officer failed to detect the error, hydraulic pressure was not available to lower the landing gear and deploy the flaps. Both the captain and the first officer recognized that the flaps had not extended after the flaps were selected to 15 deg. The pilots then failed to perform the landing checklist and to detect the numerous cues alerting them to the status of the landing gear because of their focus on coping with the flap extension problem and the high level of workload as a result of the rapid sequence of events in the final minute of flight. The first officer attempted to communicate his concern about the excessive speed of the approach to the captain. There were deficiencies in Continental Airlines' (COA) oversight of its pilots and the principal operations inspector's oversight of COA. COA was aware of inconsistencies in flightcrew adherence to standard operating procedures within the airline; however, corrective actions taken before the accident had not resolved this problem.