The terrain awareness and warning system was also switched on, the source in the mixed Indonesian-Russian team said.
Media speculated earlier, citing photos from the cockpit before the jet’s final flight, that the system might have been turned off, which may have been the reason why the plane crashed into a mountain outside Jakarta on May 9, killing all 45 on board.
Experts were still studying data from the flight recorder on Monday, while rescuers continued to look for the second “black box” at the site of the crash.