The Aircraft Accident Investigation Bureau titled its 4 September paper an accident. Flight AI2379, Airbus A320-251N VT-EXO, was two hours out of Phuket with 145 people when, at 04:02:43 UTC, the flight-control computers saw the green hydraulic system lose pressure. Four seconds later they saw blue and yellow go with it. Autopilot dropped. A chime ran. A stall warning sounded for about two seconds. The aeroplane rose 372 feet above Flight Level 360 and then fell 292 feet. Blue pressure came back first, then yellow and green. The rest of the sector to Delhi was flown and landed. Twenty passengers and four cabin crew were hurt. Four people went to hospital. Ceiling panels cracked. Bin doors came off. A lavatory commode left its mounts. The seat-belt sign was off. The crew and ATC reported no adverse weather. That sequence is in the preliminary report. The cause of the triple pressure loss is not.
An A320 is built so that green, blue and yellow are separate circuits. They power flight controls, gear, brakes and steering. Designers treat a simultaneous loss as vanishingly rare because the point of three systems is that two survive if one dies. Investigators therefore have to ask whether a common-mode path existed on this aeroplane that day. A sensor or computer that declared three hydraulic Systems died, a maintenance state that linked the circuits, the Power Transfer Unit that had already been carried as a Minimum Equipment List item for a week, an environmental or contamination event, or something the recorders have not yet explained. Airbus had already told the airline, from flight-data review, that elevator and aileron authority was disrupted for about four seconds. Four seconds at cruise is long enough to throw unbelted bodies into the ceiling. It is also short enough that a crew which stays in the loop can still own the aeroplane. The co-pilot was pilot flying when the warnings started. The commander took control. The jet arrived on its wheels in New Delhi. That is not a hydraulic footnote. That is airmanship after a failure the type is not supposed to present.
The same report records that the commander’s confirmatory laboratory test was non-negative for a psychoactive substance and that the co-pilot’s was negative. AAIB called that finding a serious concern and asked DGCA to act. Aviation Safety Expert Capt S.S. Panesar says that why AAIB did not write that the substance caused the hydraulics to fail or the altitude to change. Those are different sentences. Screening kits can react to some foods and medicines. That is why a non-negative screen is sent to a confirmatory lab. Confirmatory methods are built to name a specific compound and cut the false-positive rate of a cup test. They are not perfect, they don't present a flying history.
One account circulating around the probe is that the commander spoke of sleeping medication. That claim is not the AAIB’s finding. Fitness-for-duty rules exist so impairment never has to be argued after the fact. They can require grounding, treatment and a later medical return on a first confirmed result. They do not require the public to pretend the hydraulic event was a character study. The people who were standing in the aisle when the nose moved were injured because the sign was off and the cabin was live. Airlines still serve at cruise as if clear-air and system shocks were someone else’s problem. Seat-belt policy is part of this accident even if no one likes that sentence.
Two truths emerge from one file. The aeroplane presented a failure that should have been almost impossible, and the crew brought 145 people to a runway. Removal from the roster while medicine and maintenance are examined is procedure. Treating the landing as an inconvenience on the way to a dismissal is not investigation. AAIB has FDR and CVR, the post-flight report, the MEL history, blood work and French accredited help. Until those pages say why three colours went dark together, the country should hold the cause open, keep the cabin-safety lesson and credit the hands that still had an aeroplane when the seconds ran out. The ability of the pilot who landed the aicraft inspite of the total failure of three hydraulic systems, who manually steered the aircraft up to its destination and did not make it to befall is something that deserves the highest accolades. This act surely does not deserve a termination letter. What kind of flight safety concern does AAIB want to convey to the world?