Investigators believe the Air India Boeing Dreamliner had its emergency-power generator operating when it crashed last week in India's Ahmedabad, the Wall Street Journal reported on Wednesday citing people familiar with the probe.

Was the Boeing 787-8 Dreamliner that crashed over Ahmedabad seconds after taking off airworthy? When was it overhauled and maintained last time? Was there any issue with the engine? These questions are being asked the pilot sent the Mayday signals immediately after the plane could take off.