Air India has terminated the employment of the pilot-in-command of its August 4 Phuket-Delhi flight after a post-incident drug test detected a psychoactive substance. The decision came after the aircraft suffered a sudden altitude upset while cruising, leaving 20 passengers and four crew members injured.
According to a preliminary report released by the Aircraft Accident Investigation Bureau (AAIB) on Friday, the pilot returned a “non-negative” result for a psychoactive substance in a confirmatory test. “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.
The pilot was serving as the pilot monitoring at the time, meaning the crew member who was not operating the aircraft’s primary controls. The co-pilot tested negative in both rounds of testing.
However, the AAIB report found no evidence linking the substance detected in the pilot’s system to the aircraft’s altitude upset. “Detailed investigation regarding technical and other aspects is underway,” the report said.
The AAIB has recommended that the Directorate General of Civil Aviation (DGCA) take appropriate action to prevent the misuse of psychoactive substances, calling the issue a serious safety concern.
The aircraft left Phuket at 7.11 am IST and initially reported no abnormalities. It entered the Kolkata Flight Information Region at around 9.10 am. At 9.32 am, the aircraft detected a failure in its green hydraulic system. Within four seconds, the blue and yellow hydraulic systems were also reported to have failed.
The hydraulic systems control several critical aircraft functions, including flight-control surfaces, landing gear, wheel brakes and nose-wheel steering. The autopilot disengaged moments later, accompanied by a continuous warning chime. A stall warning was also triggered for two seconds. The aircraft subsequently experienced an altitude upset.
“The aircraft encountered altitude upset. Initially, it gained 372 ft and fell by 292 ft from its assigned FL360 during the event,” the AAIB said. The blue hydraulic system was restored first, followed seconds later by the yellow and green systems. This restored control of the aircraft’s control surfaces and allowed the flight to return to normal operating conditions. The AAIB’s technical investigation into the incident remains ongoing.
