Indian investigators have released a preliminary report about an accident that left nearly two dozen passengers and crew of an Air India flight from Phuket to Delhi injured last month.
The report published by the Aircraft Accident Investigation Bureau on Friday found that the aircraft’s three hydraulic systems lost pressure within four seconds, disengaging the autopilot and setting off a continuous cockpit alarm.
The Airbus, cruising at 36,000ft, initially ascended 372ft then fell to 292ft below it. The investigators did not clarify why the pressure loss occurred.
A stall warning during the rapid pitch up and down threw passengers and cabin crew against overhead bins, injuring 24.
The 4 August incident was updated to “accident” from “serious incident” by investigators, with the report throwing light on a chaotic few seconds aboard a jet carrying 137 passengers and eight crew.
Air India had claimed the incident was caused by severe turbulence, but the investigators said that was unlikely because the pilots and the air traffic control had not reported adverse weather.
The Airbus is equipped with three independent hydraulic systems – green, blue and yellow – to provide redundancy. If one system fails, the remaining systems can continue supplying hydraulic power.
open image in galleryAt the time of the accident, the report said, the 32-year-old first officer was flying the plane, but then the 34-year-old captain took over. Both were interviewed as part of the investigation.
The captain later returned a “non-negative” result in a confirmatory test for psychoactive substances.
“The confirmation of use of psycho-active substances is a serious concern and AAIB recommends appropriate actions by DGCA,” the report said, referring to India’s aviation regulator.
It did not specify the substance consumed by the captain, but Reuters reported that it was marijuana.
The pilots were required to undergo a screening for drugs after the accident and the captain’s first test returned a result that required confirmatory testing, the civil aviation ministry said earlier.
The new report adds to scrutiny of Air India, which is under intense regulatory and public pressure since the June 2025 crash of one of its Boeing 787s in Ahmedabad killed 260 people.
Air India said it was cooperating fully with the probe and giving investigators access to operational, maintenance and technical records.
India’s second-largest airline is implementing a one-time mandatory substance testing for all pilots after the accident, expanding checks beyond regulatory requirements.
The India government is considering annual drug testing of all pilots after the accident as against the current requirement that 10 per cent be tested each year.