Reports that an Air India pilot tested positive for cannabis following a flight have raised questions about aviation safety and whether drug use could have contributed to an incident in which an aircraft suddenly lost altitude.

However, the reported test result has not been officially confirmed by Air India. Even if confirmed, a positive cannabis test would not necessarily prove that the pilot was impaired while operating the aircraft.

What Happened on the Air India Flight?

On 4 August, an Air India Airbus A320 travelling from Phuket to Delhi suddenly lost around 91 metres (300 feet) of altitude.

The incident injured 13 passengers and four crew members. The aircraft, carrying 137 passengers and eight crew members, eventually landed safely in Delhi.

The incident remains under investigation.

Both pilots underwent routine post-flight screening for psychoactive substances, according to India’s aviation ministry.

The ministry said the captain’s initial test produced a result requiring confirmatory testing. Both pilots were subsequently removed from flying duties while the investigation continues.

Was the Pilot Confirmed to Have Cannabis in His System?

Several media reports, citing unnamed sources, later claimed that the captain’s confirmatory laboratory test was positive for marijuana.

However, Air India has not officially confirmed the reported result.

That distinction is important because an initial screening result is not necessarily considered conclusive. Confirmatory laboratory testing is used to establish whether a substance or its metabolites are actually present.

Until the relevant authorities release an official finding, the reported positive result should therefore be treated as an allegation rather than an established fact.

Does a Positive Cannabis Test Prove Impairment?

Not necessarily.

This is one of the most important issues investigators will have to consider.

Cannabis can affect reaction time, attention, coordination and decision-making while a person is intoxicated. But some drug tests detect THC metabolites, which can remain in the body after the effects of cannabis have worn off.

As a result, detecting cannabis in a biological sample does not automatically establish when the substance was consumed or whether the person was impaired at the time of the flight.

Investigators therefore need to look beyond a single test result.

What Will Investigators Examine?

The aviation investigation is expected to consider multiple possible explanations for the sudden loss of altitude.

These can include:

• Aircraft or technical problems
• Pilot inputs and operational procedures
• Medical factors
• Environmental conditions
• Human factors
• Crew coordination
• Training and workload
• Any evidence of substance-related impairment

The reported cannabis test may form part of that evidence, but it would not by itself establish the cause of the incident.

Why the Timing of the Test Matters

The central question is not simply whether cannabis was detected.

Investigators need to determine whether the pilot was impaired at the time the aircraft lost altitude.

A test performed after landing may indicate exposure to cannabis, depending on the type of test used, but interpreting that result requires understanding the testing method, the concentration detected and the relevant timeframe.

That makes it difficult to use a positive result alone to reconstruct a pilot’s condition several hours earlier.

No Link to the Incident Has Been Established

At present, there is no official finding linking the reported cannabis test to the aircraft’s sudden loss of altitude.

The investigation is still examining the wider circumstances surrounding the incident.

The reported test result is therefore significant enough to warrant scrutiny, but it should not automatically be interpreted as evidence that cannabis caused the aircraft to lose altitude.

The final investigation will need to establish what happened in the cockpit and whether any medical, technical, operational or human factors contributed to the incident.

What the Reported Result Really Tells Us

If the confirmatory result is eventually officially established, it could provide investigators with evidence that cannabis exposure occurred.

But that is different from proving impairment during the flight.

The distinction is particularly important in aviation investigations, where conclusions must be based on a combination of evidence rather than a single test.

Until the investigation is complete, it remains unclear what caused the Air India aircraft to suddenly lose altitude — and whether the reported cannabis test has any connection to the incident.