Air India said in a statement on Friday that it has terminated the pilot-in-command (PIC) of its August 4 Phuket-Delhi flight after the aircraft experienced a sudden loss of altitude in cruise, injuring 20 passengers and 4 crew members.

The pilot tested “non-negative” for a psychoactive substance in a confirmatory test, according to a preliminary report released by the Aircraft Accident Investigation Bureau (AAIB) on Friday.
“Safety remains Air India's highest priority. The Pilot-in-Command of the Phuket-Delhi flight tested positive for a psychoactive substance. In line with Air India's zero-tolerance approach to violation of safety, fitness or regulatory requirements, the pilot's employment has been terminated with immediate effect,” an Air India spokesperson said in a statement.
What AAIB report said
The report said the PIC was the pilot monitoring, meaning the crew member on a two-pilot aircraft who was not handling the primary controls at the time. The copilot tested negative in both tests.
The report did not find any connection between the detection of the psychoactive substance and the altitude upset. “Detailed investigation regarding technical and other aspects is underway.”
{{/usCountry}}The report did not find any connection between the detection of the psychoactive substance and the altitude upset. “Detailed investigation regarding technical and other aspects is underway.”
{{/usCountry}}The AAIB advised the aviation regulator, Directorate General of Civil Aviation (DGCA), to take appropriate action as deemed fit to prevent the misuse of psychoactive substances.
It described the use of such substances as a serious concern and said a detailed investigation into the technical and other aspects was still underway.
Loss of hydraulic systems
The flight departed Phuket in Thailand at 7.11am IST and initially reported no issues. At 9:10am, it entered the Kolkata Flight Information Region.
At 09:32 am, the aircraft's flight-control system detected a loss of the green hydraulic system. Four seconds later, it detected the loss of the blue and yellow hydraulic systems.
Hydraulic systems operate several aircraft components, including wheel brakes, nose-wheel steering, landing gear retraction, flight control surfaces, windshield wipers, and propeller pitch control.
Later, the autopilot disengaged, and a continuous repetitive chime began. Three seconds later, the stall warning was activated for two seconds.
“...the aircraft encountered altitude upset. Initially, it gained 372 ft and fell by 292 ft from its assigned FL360 during the event,” the AAIB report said.
It added that the blue hydraulic system was restored around 09:32am. The yellow and green hydraulic systems were restored a few seconds later, restoring control of the surfaces and allowing the aircraft to return to normal operating conditions.
Deep Dive
What led to the termination of the Air India pilot after the Phuket-Delhi flight?
What investigations are being conducted regarding the pilot's drug test results?
How is Air India responding to safety concerns after the incident?
More details will be added shortly