India, Sept. 4 -- Air India on Friday responded to the Aircraft Accident Investigation Bureau's (AAIB) preliminary report into the Phuket-Delhi flight incident. The airline said it has started voluntary testing of 100% of its pilots to further strengthen safety measures.

The AAIB report found that the pilot-in-command tested "non-negative" for a psychoactive substance in a confirmatory test. It called the finding a "serious concern" and recommended that the Directorate General of Civil Aviation (DGCA) take appropriate action.

Air India said it continues to fully cooperate with the probe and has provided access to all relevant operational, maintenance and technical records.

"We acknowledge the release of the preliminary report by the Ai...