All 189 people on board died when Flight JT610 fell into the sea shortly after taking off for the short journey to Pangkal Pinang.
The pilot had asked air traffic control for permission to turn back to the airport but then contact was lost.
Investigators say the plane had encountered technical problems.
The aircraft - a new Boeing 737 Max - broke into many pieces when it hit the water at high speed. The plane should not have been flying on the day it went down as it was not airworthy, Indonesian investigators have said.