Piper PA-28-161 N140FT incident near St. Augustine, Florida

Probable cause

The pilot's failure to adhere to the controller's takeoff instruction. Contributing to the incident was the controller's failure to properly monitor the flight, and the controller's decision to perform lesser duty priorities during the takeoff roll.

NTSB analysis

The airplane departed on runway 6 at St. Augustine (SGJ) Airport, St. Augustine, FL, and proceeded off the end of the runway into the marshy waters of the Intracoastal Waterway. According to the pilot, "The air traffic controller told me that I was good there and gave me clearance to depart 31. I understood that to mean I was on [runway] 31 and clear for departure so I completed my pre-takeoff checklist and began my ground roll. Then I noticed I was on the wrong runway and tried to stop, but was too late and the momentum carried me into the marsh." According to the FAA's preliminary report, the student solo pilot arrived from Deland, Florida and requested to taxi back to the active runway for departure. The controller instructed the pilot to make a left turn on B2 then taxi to runway 31 via taxiway B, and hold short of runway 31 at taxiway B4. The pilot acknowledged the clearance. The pilot taxied past taxiway B4 and went onto runway 6/24. While on runway 6/24 and short of runway 31, the pilot requested progressive taxi instructions from the tower controller. The controller advised the pilot, "You're fine where you're at. Are you ready to go?" The pilot stated that he was ready to depart. The controller instructed "Zero foxtrot tango, runway 31 at runway six intersection, cleared for takeoff left turn southbound." The pilot read back "cleared for takeoff." According to the preliminary report, the tower controller observed the aircraft make a turn onto runway 31 at runway 6 intersection and then returned to do administrative duties, (the hourly weather). The pilot had departed straight ahead on runway 6 from the intersection of runway 6/31 with approximately 200 feet of runway remaining. A short time later the pilot buzzed the tower door and advised the controller that he had ran off the runway into the Intracoastal Waterway.

Text from the NTSB. Open the NTSB docket for OPS08IA006 for the full record.