New Delhi, Sept. 11 -- The aviation regulator has ordered airlines to conduct one-time psychoactive substance tests on all pilots, with testing in the current cycle running until July 31 next year, people aware of the matter said on Thursday, days after the August 4 Phuket-Delhi Air India flight pilot-in-command tested "non-negative" for such a substance. An official said testing of pilots across all airline operators is currently underway. "An order has been issued," the official said. A second official said tests began last month. HT was the first to report last month that the government was examining increasing the scope of random testing, with the possibility of every pilot being tested at least once a year. The government is working on amending the drug test rule. The new testing mandate marks a significant expansion of the existing regime under which 10% of flight crew and air traffic controllers are randomly tested for psychoactive substances annually. Asked about an amendment to the drug test rule, civil aviation minister Ram Mohan Naidu on Thursday said the government is moving for a change by the month end. "...the DGCA [Directorate General of Civil Aviation] is still holding discussions with stakeholders, but hopefully before the end of this month, we will be able to finalise." On any action against the Phuket-Delhi PIC, he said the DGCA has to do that....