Air India has ordered immediate substance testing for all its pilots, going beyond existing aviation rules, following an incident in which a flight from Phuket to Delhi suddenly lost altitude shortly after take-off.
The airline said the new tests will cover pilots at both Air India and its budget carrier, Air India Express, with the exercise also targeting substances and medications prohibited under aviation regulations.
The move comes after the August 4 incident involving an Airbus flight that dropped about 91 metres (300 feet) in height soon after leaving Phuket. Seventeen passengers and crew members were injured during the incident.
A preliminary report said the senior pilot had to retake a substance test. Reports have said the pilot initially tested positive for marijuana, although the incident remains under investigation.
Both pilots who operated the flight have since been removed from duty while Indian authorities continue investigations in cooperation with Airbus and France's air safety agency.
Air India said it was taking the wider testing step to strengthen safety checks across its operations.
In a memo seen by the BBC, the airline said it was "important to go further" in its testing.
"This initiative, which goes beyond regulatory requirements, reflects our determination to uphold the highest standards of safety and professionalism, and to provide reassurance to our passengers, stakeholders and the community at large," it said.
Under existing rules, airlines are required to randomly test at least 10% of their pilots for banned substances. Air India's new plan will subject all its pilots to testing, while pilots at Air India Express will also begin undergoing the checks from Thursday.
The tests are being conducted at several locations, including the airline's academy, briefing centres and offices. They are being carried out alongside training sessions.
The latest move comes as Air India continues to face close attention over flight safety following a fatal crash in June 2025.
That flight, which was travelling from Ahmedabad to London, crashed shortly after take-off, killing 241 people on board and 19 people on the ground. Only one passenger survived the crash.
Air India also appointed former Ethiopian Airlines boss Tewolde Gebremariam as its new chief executive last week, adding a new leader to the airline as it works through increased safety scrutiny.
The Phuket-Delhi incident is still being investigated, with authorities examining what caused the sudden loss of altitude and the circumstances surrounding the flight.