The calmly spoken “all right, good night” final known words from the missing jet may have been spoken by the co-pilot, Malaysia Airlines' CEO said Monday.
Initial investigations indicated the phrase came from First Officer Fariq Abdul Hamid and not his superior Capt. Zaharie Ahmad Shah, Ahmad Jauhari Yahya told a news conference.
He added that authorities were trying to determine whether the voice sounded stressed.
"All right, good night" was uttered to Malaysian air traffic controllers in response to the routine handover to their Vietnamese counterparts.
Officials previously confirmed that those words came at a point in the March 8 flight when the jet's ACARS (Aircraft Communications Addressing and Reporting System) automatic tracking system had already been switched off, fueling suspicions that one or both of the pilots may have been involved in the plane’s disappearance.