New Delhi, Aug. 14 -- Air India and Air India Express will begin screening of all their pilots psychoactive substance from Thursday after the commander of a Phuket-Delhi flight that lost altitude sharply last week tested positive for marijuana, even as the Centre is planning to amend rules to enforce stricter action against pilots testing positive for drugs, people familiar with the matter said. "We have decided to undertake a full screening of all Group pilots for any substances or medications that are not permitted under prevailing regulations. This testing is mandatory and will start today, 13 August 2026," Manish Uppal, head of flight operations, Air India, wrote in an email to all pilots of the group. HT has seen the email. "It will be conducted concurrently with training at the Gurugram academy, post flight at our Flight Briefing Centres / Air India Offices, or at locations provided by your respective bases," the internal communication added. Air India and Air India Express together have around 5,000 pilots. The move follows an August 4 incident involving Air India flight AI2379, an Airbus A320neo flying from Phuket to Delhi, which suddenly lost about 300 feet in altitude during cruise. While the case is being investigated by the Aircraft Accident Investigation Bureau (AAIB), the pilot-in-command tested positive for marijuana in an initial, and a second confirmatory, test early this week. A preliminary defect report prepared by the pilots suggested the incident was preceded by multiple technical glitches, including an autopilot disconnection. Meanwhile, people aware of the matter said the government is planning to amend the drug-testing rules for aviation personnel. "The Directorate General of Civil Aviation (DGCA) will review the existing civil aviation requirements (CAR) on testing for psychoactive substances, with a possible increase in random testing and stronger penalties under the revised framework," one of the people said, requesting anonymity. The current CAR, effective since January 2022, requires scheduled commercial airlines, air traffic controllers, flight training organisations and air navigation service providers to conduct random drug tests covering at least 10% of employees annually. The rules also provide for removal from safety-sensitive duties following a non-negative screening result....