Airbus SE discovered hydraulic system faults on an Air India Ltd. jet that dropped about 300 feet in mid-flight last week, according to a preliminary assessment by the planemaker. The DFDR reading of Air India flight AI-2379 from Phuket to Delhi showed a 4-second loss of control surfaces caused a sudden 300-foot mid-air drop. During this window, the A-320 NEO’s elevators and ailerons drifted without pilot command due to a total failure of the aircraft's three hydraulic systems. The autopilot disconnected immediately, and co-pilot inputs had no effect during cockpit stall warnings until hydraulic systems recovered.

Air India ordered mandatory drug testing for all pilots after Captain Sudeep Vashistha failed post-flight urine tests for marijuana. The pilot’s conduct is under investigation, but no direct link to the incident has been established. Airbus linked the emergency to a potentially faulty hydraulic pressure switch, though no definitive root cause was identified. A technical team from Airbus and BEA examined the aircraft, and findings were shared with India’s Aircraft Accident Investigation Bureau.

Hydraulic systems are critical for controlling flight surfaces like elevators, ailerons, and spoilers. The failure of all three systems left the aircraft vulnerable, highlighting risks in aviation safety protocols. The incident underscores the importance of robust maintenance and real-time data analysis in preventing such emergencies.