New Delhi, Aug. 13 -- Air India started testing all its pilots and copilots for psychoactive substances on Thursday-the first such group-wide exercise since the Tata Group took control of the airline in January 2022, two people familiar with the development said.

The mandatory one-time screening comes after the pilot-in-command of an Air India Phuket-Delhi flight tested positive for a banned substance, one of the two people said. The aircraft suddenly plunged about 300 feet while cruising last week and 20 passengers and four cabin crew members were injured. Air India and the ministry of civil aviation have not disclosed the identity of the pilot or detailed the test results.

The airline has decided to undertake a "full screening" of all...