On August 4, Air India flight AI2379, an Airbus A320neo flying from Phuket to Delhi, suddenly lost about 300 feet of altitude over Odisha, injuring passengers and crew. The Aircraft Accident Investigation Bureau (AAIB) is investigating, with Airbus and France’s Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA) assisting. Airbus’ preliminary analysis indicates that pressure was temporarily lost in all three hydraulic systems, briefly disabling key flight controls for about four seconds. A separate inquiry was initiated after the captain’s post-flight psychoactive-substance screening reported a non-negative result. A subsequent confirmatory test is said to have tested positive for marijuana. Both pilots were grounded pending investigation.
What are the questions raised by the incident?
The incident therefore raises two different questions. What caused the aircraft to lose altitude? And how did a pilot who subsequently tested positive for a prohibited substance operate an international flight in the first place? The first belongs to the accident investigation. The second goes to the design of India’s aviation safety net.
A positive drug test cannot, by itself, establish that a pilot was impaired at the precise time of operating an aircraft. This distinction matters because the captain’s initial screening was a urine test. The test detects drug metabolites that can remain in the body after the psychoactive effects have worn off. A positive result can therefore establish prior exposure without, by itself, establishing when the drug was consumed or whether the pilot was impaired while flying. That does not make the Phuket result insignificant. A confirmed positive result for a prohibited substance is a serious regulatory matter. But investigators must establish when the substance was consumed, whether the pilot was impaired, whether any medication was involved and whether the result can be connected to the pilot’s performance.
How strict are India’s rules on alcohol and drugs?
India’s basic rules are unequivocal. Rule 24 of Aircraft Rules bars operating crew from consuming alcohol, sedatives, narcotics or stimulant drugs within 12 hours of a flight, using them during a flight, operating while intoxicated, or flying when their capacity is impaired. DGCA rules also require no detectable blood alcohol in the prescribed testing process. For psychoactive substances, however, the framework is not so watertight. It relies on random testing by airlines of at least 10% of the flight crew annually.
What is the limitation?
A 10% annual random testing is more of a surveillance mechanism than a preventive measure. Pilots generally report for duty without a drug test for a flight. Alcohol is easier to screen: crew undergo mandatory breathalyser testing at the first departure airport during a flight-duty period. Drug testing is different. Different substances have different detection windows, and a positive screening result requires laboratory confirmation. India’s system therefore draws a clear distinction between prohibiting substance use and detecting it before a particular flight.
How has Air India responded to the Phuket incident?
Air India ordered one-time substance screening of all about 5,000 pilots, including those of Air India Express, going beyond the existing annual regulatory minimum. The testing is being carried out at training sessions, after flights and at designated locations. The question is whether such comprehensive screening should remain an exceptional response or whether parts of it should become a permanent safety mechanism. Furthermore, the question that still stands is that will these surveilling measures be able to address the question of preemptive detection? The problem is not solved merely by increasing annual random testing from 10% to 20% or 25%. A pilot can still be tested on one day and operate many flights without being tested on another. A stronger system would combine random selection with testing at operational touchpoints, particularly where the crew is departing from an international station.
Why are international outstations a particular challenge?
At major Indian bases, airlines have established systems for pre-flight alcohol testing, medical checks and operational supervision. An international flight begins somewhere else. The crew may spend a day or more at an overseas station, away from the airline’s principal medical and operational infrastructure. This does not mean that international stations are unregulated or that Phuket lacked safeguards. It does mean that the regulator and airline have to answer a specific question: what independent mechanism exists at an overseas departure point to detect a pilot who may be unfit to fly? The difference matters because the most valuable test is the one that prevents an unsafe person from entering the cockpit.
Has India faced similar bottle-to-throttle problems with alcohol?
The history of alcohol violations shows that the problem is not new and that pre-flight testing can work when it is actually deployed. In 2012, an Air India commander scheduled to operate the Delhi-Jammu-Srinagar sector reportedly bypassed the mandatory pre-flight breathalyser test and went to the aircraft. The alerted Air Traffic Control (ATC) refused clearance. The pilot was removed from the cockpit, tested and found positive for alcohol. In 2016, two pilots—one from Air India and another from Jet Airways—were found positive for alcohol in post-flight tests. DGCA suspended both licences for four years and directed that FIRs be lodged. The most prominent case came in 2018, when Air India Director of Operations Captain Arvind Kathpalia failed the pre-flight breathalyser before a Delhi-London flight. He had previously been suspended for three months in 2017 after operating a flight without undergoing the mandatory test. DGCA suspended his licence for three years after the 2018 violation. In April 2024, an Air India pilot tested positive during the mandatory pre-flight alcohol test before a Delhi-Hyderabad flight and was grounded for three months. The previous month, Air India had terminated another pilot who had operated an international flight under the influence of alcohol.
So, the existing system has, in several instances, detected pilots before they could operate a flight, unlike the case in Phuket, where the initial drug finding emerged after the flight. That difference lies at the heart of the regulatory question: whether India’s existing pre-flight safeguards are sufficient to detect substances other than alcohol, and whether post-flight testing can compensate when pre-flight screening does not detect a potential impairment.
How do other countries approach pilot drug and alcohol testing?
The US system combines strict operational prohibitions with formal employer-run drug and alcohol testing programmes under 14 CFR (Code of Federal Regulations) Part 120. The Federal Aviation Administration also specifies minimum annual random-testing rates and requires employers or Medical Review Officers to report verified positive results. Australia goes further in putting the regulator directly into the operational environment. Under its Part 99 framework, the Civil Aviation Safety Authority operates a regime of random testing and can conduct non-notice testing. The system covers people performing safety-sensitive aviation activity.
The UK Civil Aviation Authority provides another useful model. Its ramp-inspection programme allows random or suspicion-based alcohol testing of flight and cabin crew. A positive result means the crew member cannot continue duties on that flight; refusal to cooperate also prevents continuation of duty. The UK has also explicitly incorporated operator responsibilities for preventing people from boarding aircraft when under the influence of psychoactive substances, alongside procedures for prevention and detection and support programmes for flight crew. The common principle is not a particular testing percentage. It is layering: employer controls, regulator oversight, random testing, reasonable suspicion, post-incident testing and mechanisms for removing an unfit crew member before departure.
