Air India has ordered mandatory drug screening for all its pilots after the captain of the Phuket-Delhi flight that suddenly lost altitude tested positive for marijuana in a confirmatory test. The move comes as a separate technical investigation into the August 4 incident reveals that the Airbus A320neo briefly lost control of key flight surfaces after problems affected all three of its hydraulic systems.
The developments have put Air India safety, pilot fitness, aircraft maintenance and flight-control systems under intense scrutiny. The aircraft, operating as flight AI2379 from Phuket to Delhi, dropped about 300 feet during the incident, leaving 24 passengers and crew members injured. It later landed safely in Delhi.
Air India has begun substance screening for around 5,000 pilots across Air India and Air India Express. The airline’s decision goes beyond the existing regulatory requirement under which at least 10% of flight crew are randomly tested each year for psychoactive substances. The expanded exercise is intended to reassure passengers and strengthen confidence in the airline’s safety procedures.
The airline’s action follows the confirmatory test of the pilot-in-command of AI2379. Both pilots underwent mandatory screening after the August 4 incident, but the captain’s initial result was not negative and was sent for laboratory confirmation. The subsequent test confirmed the presence of marijuana. The captain and first officer had already been removed from flying duties pending the investigation.
Importantly, investigators have not established a link between the captain’s positive drug test and the aircraft’s sudden loss of altitude. The technical findings emerging from the investigation point towards a separate and unusual malfunction involving the aircraft’s hydraulic systems.
According to Airbus‘ preliminary assessment of the flight data recorder, the A320neo experienced a loss of hydraulic pressure involving all three of its independent hydraulic systems. The problem temporarily affected the aircraft’s elevators and ailerons, which are essential for controlling its pitch and roll. The loss of effective control lasted approximately four seconds.
The four-second period was critical. The aircraft’s control surfaces did not immediately respond to pilot inputs, even as the crew attempted to stabilise the aircraft. The first officer applied full nose-down input after the aircraft began pitching up, but the controls initially failed to respond. Hydraulic pressure subsequently returned, allowing the aircraft’s flight-control surfaces to operate normally again.
The aircraft’s sudden movement caused passengers and crew members to be thrown around the cabin. Twenty-four people were injured in the incident. Despite the loss of altitude and temporary control problem, the pilots were able to regain control and continue the flight to Delhi.
The Airbus findings are significant because the A320 family is designed with multiple hydraulic systems to provide redundancy. A problem in one system should not ordinarily result in the loss of control of critical flight surfaces. The fact that all three systems were affected within a short period has therefore become a major focus of the investigation.
However, Airbus has not yet established what caused the hydraulic pressure loss. The manufacturer has sent an initial assessment to Air India and asked the airline to provide detailed maintenance records and technical information. Investigators are examining the aircraft’s hydraulic components, sensors and related systems to determine whether there was an actual mechanical failure or whether an erroneous signal may have contributed to the event.
The investigation is being led in India as a serious aviation incident, with technical assistance from Airbus and France’s Bureau of Enquiry and Analysis for Civil Aviation Safety, or BEA. The Aircraft Accident Investigation Bureau is examining flight-data recordings, aircraft systems, maintenance history and the actions of the crew.
The preliminary Airbus assessment has also provided investigators with a clearer timeline of the incident. During the brief malfunction, the aircraft lost effective control of major surfaces before the hydraulic systems recovered. The episode was short but severe enough to produce the sudden 300-foot altitude change that startled passengers and injured people inside the cabin.
At the same time, the positive drug test has opened a second line of scrutiny for Air India and aviation regulators. Pilot drug testing, substance abuse, crew fitness and cockpit safety are now receiving greater attention. The Directorate General of Civil Aviation (DGCA) is reviewing its existing rules and considering whether stricter measures are required when pilots test positive for prohibited substances.
The regulatory review may also examine how positive tests should be treated when they involve medicines taken for legitimate medical reasons. This distinction is important because aviation authorities need to ensure that pilots are not impaired by prohibited substances while also recognising that some medications can produce positive screening results or affect fitness to fly.
Air India’s decision to test its entire pilot workforce represents a major expansion of its immediate safety response. The screening will cover pilots at training facilities and other designated locations before the airline returns to the regular testing framework.
The two developments — the marijuana-positive pilot test and the rare hydraulic malfunction — are being examined separately. There is currently no evidence that the captain’s test result caused the aircraft’s loss of altitude. The technical investigation must establish whether the four-second loss of control was the result of a genuine hydraulic failure, a sensor or electrical problem, or another fault.
The Phuket-Delhi incident has consequently raised questions on two fronts: the effectiveness of pilot drug screening and the reliability of critical aircraft systems. Air India’s expanded testing addresses the first concern, while Airbus and Indian investigators continue to work on the second.
