An Air India Airbus A320 operating flight AI2379 from Phuket to Delhi suffered a rare and serious technical failure on August 4, when all three of its hydraulic systems temporarily lost pressure while the aircraft was cruising at 36,000 feet. The incident triggered an autopilot disconnect, a stall warning and a sudden altitude upset, with the aircraft briefly losing key flight-control functions.
According to the preliminary findings of the Aircraft Accident Investigation Bureau (AAIB), the aircraft first detected a loss of pressure in the green hydraulic system, followed within seconds by losses in the blue and yellow systems. The simultaneous failure of all three systems is considered extremely rare on the A320. The aircraft subsequently recovered and landed safely in Delhi, while 24 people on board sustained injuries.
The preliminary report has also flagged a non-negative psychoactive-substance test involving the pilot-in-command and recommended that aviation regulator DGCA take appropriate action. However, the investigation has not established that the pilot’s test result contributed to the hydraulic failure or the altitude upset. The AAIB probe into the technical and operational aspects of the incident remains ongoing.