Cessna 550 Citation II, Butler, Pa., Jan. 24, 2007–The NTSB attributed the runway overrun of the air ambulance Air Trek Citation II to the copilot’s failure to maintain proper airspeed and failure to land at the proper touchdown point, and the pilot-in-command’s inadequate supervision. Factors were the PIC’s failure to activate the speed brake upon touchdown and the snow-contaminated runway. The jet touched down halfway down the 4,801-foot runway at Butler County Airport at 140 knots. The runway was covered with about a quarter to half inch of loose, “fluffy” snow. Review of the cockpit voice recorder suggested that the PIC failed to activate the airplane’s speed brake upon touchdown. The ATP-rated pilot was seriously injured and the jet substantially damaged.