Probe agency finds psychoactive substance use by pilot of Air India flight from Phuket, suggests appropriate action

The Aircraft Accident Investigation Bureau (AAIB) has found that the pilot-in-command of an Air India flight from Phuket to Delhi tested positive for a psychoactive substance in a confirmatory test and has recommended that the Directorate General of Civil Aviation (DGCA) take “appropriate action” on priority.

The preliminary report does not link the pilot’s psychoactive-substance test result to the altitude upset or establish the cause of the hydraulic-system disruption yet.

The 4 August incident involved Air India flight AI2379, an Airbus A320-251N carrying 145 people. The flight lost pressure in all three hydraulic systems while cruising at 36,000 feet, gained 372 feet and then fell 292 feet, injuring 24 people, the report said. AAIB has not stated the cause of the loss of hydraulic pressure.

AIBB does not name the substance or the pilot but uses the regulatory term “non-negative” in its report to describe the pilot’s test. “In this case, it has been observed that the PIC (pilot in command) was found non-negative for psycho-active substance in the confirmatory test,” the AAIB report said. “The confirmation of use of psycho-active substances is a serious concern and AAIB recommends appropriate actions by DGCA on priority.”

Both pilots underwent breath-analyser tests after landing in Delhi. They were subsequently tested for psychoactive substances. The pilot-in-command’s initial test was non-negative, following which blood samples of both pilots were sent to a laboratory for confirmation. The co-pilot tested negative in both tests.

Under DGCA rules, a first confirmed case of psychoactive-substance use does not automatically mean cancellation or suspension of a licence. The pilot is required to undergo rehabilitation or de-addiction and can return to flying only after completing the prescribed process. A second confirmed violation can result in a three-year licence suspension, while a third can lead to cancellation.

An Air India spokesperson said the airline was extending full cooperation to the investigation. “Following the incident, Air India has started voluntary testing of 100% of its pilots as a further step to reinforce its safety-first approach. The airline maintains zero tolerance for any breach of safety, fitness or regulatory requirements and will take appropriate action wherever warranted,” the person said.

Flight-control system

The report, under the section “Brief Description of Accident”, says the aircraft encountered an altitude upset during the event. The A320 has three hydraulic systems—Green, Blue and Yellow—which provide power to key aircraft systems, including flight controls. In the incident, the hydraulic systems recovered within seconds, followed by the recovery of the flight-control surfaces.

The report noted that during the incident, the flight-control system first detected a loss of pressure in the Green system at 04:02:43 UTC. Four seconds later, it detected losses in the Blue and Yellow systems. The autopilot then disengaged, followed by a continuous warning chime and a two-second stall warning. The Blue system recovered in nine seconds, at about 04:02:52 UTC, followed a few seconds later by recovery of the Yellow and Green systems. The flight-control surfaces then recovered.

UTC stands for coordinated universal time. A 04:02.43 UTC would mean 9.33 AM IST.

“No adverse weather was reported by flight crew and ATC,” the report said. This is particularly useful because the incident was initially reported as turbulence.

The report noted that with the seat-belt signs switched off, passengers and cabin crew were injured. The crew decided to continue to Delhi instead of diverting to the nearest airport. The aircraft landed safely at IGI airport, where 20 passengers and four cabin crew received medical assistance. Four people were hospitalised for further treatment.

The aircraft also sustained damage inside the cabin and not the cockpit. The damage included cracked ceiling panels, bent or dislodged passenger-service-unit panels, a broken handrail, a damaged emergency-exit handle and overhead-bin doors detached from their hinges.

The post-flight report mentions that the warnings indicated low hydraulic pressure, the autopilot switching off and problems with the elevators, which help control the aircraft’s nose-up and nose-down movement.

The incident was initially reported to AAIB as a turbulence encounter, but its weather assessment says: “No adverse weather was reported by flight crew and ATC.”

AAIB said flight-recorder data had been downloaded and hydraulic components and samples collected for further analysis. Airbus technical experts also inspected the aircraft between 13 and 15 August.

“Detailed investigation regarding technical and other aspects are underway. The final report will be published in due course,” AAIB said.