Air India flight AI2379, an Airbus A320 operating from Phuket to Delhi on 4 August, experienced a sudden loss of roughly 300 feet in altitude during cruise. Twenty passengers and four cabin crew were injured. The aircraft recovered and landed safely in Delhi. Both pilots were immediately removed from flying duties. The event has been classified as a serious incident and is under formal investigation by the Aircraft Accident Investigation Bureau.
A confirmatory laboratory test of the pilot-in-command has returned positive for marijuana, according to multiple sources familiar with the process. An initial post-flight psychoactive substance screening had produced a non-negative result, triggering the mandatory confirmatory analysis required under existing procedures. The Aircraft Accident Investigation Bureau has stated that it is systematically collecting and examining technical, operational, medical and human-factors evidence in its entirety and has cautioned against drawing conclusions from any isolated piece of information while the investigation continues.
A positive confirmatory test establishes the presence of the substance in the sample analysed. It does not, by itself, determine impairment at the moment of the altitude loss, nor does it establish causation. The investigation must still establish the sequence of events, the aircraft’s systems behaviour, any meteorological or technical factors, crew actions, and the full medical and human-factors context before any finding of contribution can be made.
The episode nevertheless places Indian aviation’s fitness-for-duty framework under examination. Current Directorate General of Civil Aviation rules require that an employee whose screening is non-negative be removed from safety-sensitive duties pending confirmatory results. A first positive confirmatory result leads to referral for de-addiction and rehabilitation before any return to duty can be considered. Subsequent positives carry progressively heavier licence sanctions. The system is designed to respond after detection. The sharper question is whether the combination of random and post-incident testing, fatigue management, confidential reporting channels, peer intervention mechanisms and organisational safety culture is structured to identify and address risk before an aircraft departs.
Peer intervention programmes and non-punitive reporting pathways exist in many mature systems precisely to encourage early disclosure of substance, fatigue or medical issues without immediate career destruction. Their effectiveness depends on trust that disclosure will lead to support rather than automatic exclusion. India’s rapid fleet growth and high utilisation rates increase the operational pressure under which such systems must function. The Phuket–Delhi investigation will test whether those safeguards are robust enough to surface problems upstream of departure or whether they remain largely reactive.
Air India senior management has met civil aviation ministry officials. The regulator is reviewing substance-use provisions. The Aircraft Accident Investigation Bureau continues its Annex 13 inquiry with technical support from Airbus and France’s Bureau of Enquiry and Analysis for Civil Aviation Safety. Until the full evidence set is analysed, the positive test remains one data point among many. The broader systemic question it raises about pre-departure risk detection will outlast any single finding on this flight.