Cessna 172N N739ZE accident near Avalon, California

Probable cause

Undetermined because the airplane was not located.

NTSB analysis

The flight instructor and student pilot departed for an instructional flight from an airport on an island en route back to their home airport on the mainland. A review of radar data indicated that the airplane took off with its transponder in the "off" position; therefore, no altitude information was available. The data indicated that, after taking off, the airplane flew north. The track ended 3 minutes later over open water about 5 miles north of the departure airport. After the airplane was reported missing, a search ensued. Although an oil slick consistent with drift models was present in this area, neither the airplane nor the occupants were found.

Four minutes before the airplane took off, the reported weather at the departure airport included 9 statute miles visibility and a broken cloud ceiling at 800 ft above ground level (agl); however, the remarks section reported that the ceiling varied between 600 and 1,000 ft agl. In addition, satellite imagery indicated that there was a thick marine layer just north of the airport.

Text from the NTSB. Open the NTSB docket for WPR16FAMS1 for the full record.