Two pilots of the Air India Group have failed the initial drug test as their results came “non-negative” and their samples have been sent for confirmatory tests, according to a source.On August 13, Air India and Air India Express started mandatory psychoactive substance testing of all their pilots, expanding checks beyond regulatory requirements.These tests were made mandatory following the August 4 incident, when the captain of an Air India Phuket-Delhi flight, that suddenly lost altitude, tested positive for marijuana.The source on Monday said psychoactive substance tests have been completed for around 400 pilots of the Air India Group so far.Of them, the initial screening test results have come “non-negative” for two pilots, the source said.Specific details could not be immediately ascertained.There was no official comment from Air India.The two Tata Group-owned airlines have more than 5,000 pilots.The comprehensive screening covers substances and medications prohibited under prevailing aviation regulations.On August 4, Air India flight AI2379, an Airbus A320neo flying from Phuket to Delhi, suddenly lost about 300 feet (91 metres) in altitude during cruise amid turbulence. The aircraft was carrying 145 people — 137 passengers and eight crew members. At least 24 people were injured in the incident.The flight’s pilot-in-command tested positive for marijuana in a confirmatory drug test. The pilot had initially tested “non-negative” for a psychoactive substance, with the confirmatory test subsequently identifying marijuana, sources had said.