One person was killed and four others were missing when their helicopter crashed into the high seas having missed the landing platform, 109 km off the Brazilian coast in Rio de Janeiro.
The incident occurred at about 4.30 pm (1930 GMT) on Tuesday. The aircraft developed mechanical problems during its flight between the platforms in Campos marine base in the northern shore of Rio de Janeiro state.
Brazilian oil company Petrobras owned the helicopter. Fifteen passengers were rescued. One person was killed and four were missing, an official of Petrobras said.
Rescue teams of Brazil's navy and air force and Petrobras were carrying out the search for the missing.