Air India pilot who tested positive for marijuana slept 30-35 minutes during Phuket-Delhi flight

The pilot told investigators he had been struggling with his sleep for some time because of personal circumstances.

The commander of the Air India Phuket-Delhi flight that lost altitude suddenly on August 4, injuring several passengers, told investigators he had been struggling with sleep and was on medication prescribed by his family doctor, two people familiar with his account to the Aircraft Accident Investigation Bureau (AAIB) said. They spoke on condition of anonymity and described more than an hour of questioning by investigators.

Medical personnel with injured passengers in wheelchairs after the Air India flight (AI2379) from Phuket to Delhi experienced brief in-flight turbulence. (ANI Video Grab)

The disclosure comes a day after it emerged the pilot’s preliminary post-flight drug test was recorded as “non-negative,” a screening result indicating a sample flagged for further analysis, and that his confirmatory test came back positive for cannabis.

The pilot told investigators he had been unable to sleep during his layover in Phuket. He said he had experienced sleep difficulty for some time because of personal circumstances, one of the persons said. He did not name the medication or say how long he had been on it, the person said.

DGCA rules require pilots on prescription medication to declare it to their airline. Non-disclosure can invite action from the operator. It was not clear if the pilot had done so.

Pilot slept for 30-35 minutes

The first officer was flying the aircraft. The commander was the pilot monitoring, two people said.

A cabin crew member on the observer seat, a role a departing pilot must assign when leaving the cockpit, helped him up, the persons said. It was the first detailed account from the cockpit crew of what happened aboard flight AI2379, an Airbus A320 registered as VT-EXO.

The full sequence of events inside the cockpit could not be independently established from the pilots’ accounts to investigators. A copy of the aircraft’s post-flight Centralised Fault Display System log, seen by HT, recorded nine warning messages within one minute at 9.32am IST – a time when the flight had entered over the coast of Odisha from the Bay of Bengal.

Warning signs during flight plunge

The messages included low pressure across the Green, Blue and Yellow hydraulic systems in different combinations, low reservoir levels on the Yellow and Blue systems, an autopilot disconnect and an elevator flight-control fault. Two door emergency-exit sensor messages followed at 9.33am and 9.35am. No further hydraulic or elevator messages were logged for the next 43 minutes. A separate engine anti-ice fault was recorded at 10.16am, and a second autopilot disconnect at 10.52am. The second disconnect was not accompanied by any hydraulic messages, unlike the first. The log doesn’t state a cause.

The pressure readings toggled across different system combinations within a minute rather than one system failing and staying failed. That pattern could allude to a transient event of the kind a sharp vertical excursion — or a sudden altitude loss, as reported by those onboard and the airline. — can produce through brief fluid movement in the hydraulic reservoirs, on a reading of the log by HT against standard A320 fault-code references. A sustained mechanical failure would have thrown up more messages including a number to indicate recurrency.

Flightradar24 tracking data places the altitude event within the same minute as the fault cluster. The aircraft was cruising at 36,160 feet when an altitude anomaly was recorded at 9.33am IST. It dropped to about 35,800 feet, a loss of around 360 feet, according to Flightradar data.

Air India did not issue a statement on the development till the time of going to press.