The Directorate General of Civil Aviation (DGCA) is investigating a serious safety incident involving an Air India flight from Phuket to Delhi, after the pilot-in-command allegedly left the cockpit during the flight and attempted to smoke inside the passenger cabin, according to reports.

The incident reportedly came to light after the aircraft experienced a sudden drop in altitude, injuring 20 passengers and four cabin crew members.

According to a Times of India report, the pilot allegedly entered the passenger cabin, sat on the floor near an emergency exit and asked members of the cabin crew for a lighter. Crew members reportedly intervened and asked him to return to the cockpit.

The circumstances surrounding the pilot's alleged conduct are now part of the DGCA investigation.

Flight Suffered Sudden Altitude Drop

The incident occurred during the Phuket-Delhi flight when the aircraft reportedly lost around 300 feet in altitude.

The sudden change in altitude resulted in injuries to passengers and crew members onboard.

The DGCA subsequently began examining the circumstances of the incident, including the aircraft's operation, the actions of the cockpit crew and the events surrounding the altitude change.

The alleged conduct of the pilot inside the passenger cabin has added another dimension to the investigation.

Pilot Tests Positive for Marijuana

The pilot-in-command has reportedly tested positive for marijuana in a confirmatory laboratory test, according to CNN-News18.

Both pilots underwent mandatory psychoactive-substance screening following the incident.

The initial screening of the pilot-in-command reportedly required further confirmation, following which the sample was sent to a designated laboratory. The confirmatory test subsequently returned a positive result for marijuana.

The pilot has reportedly told investigators that he had been taking prescribed sleeping medication because of personal problems and suggested that the medication may have contributed to the test result.

That explanation is now being examined as part of the investigation, and no final conclusion has been reached regarding the cause of the positive test.

Both Pilots Removed From Duty

Air India has removed both pilots from flying duties while the investigation continues.

The airline said it follows a zero-tolerance policy towards behaviour that could compromise the safety of passengers and crew members.

Air India has also said it is cooperating with the DGCA investigation.

The action comes as aviation authorities increase scrutiny of safety procedures and psychoactive-substance testing involving flight crew.

Government Orders Review

The Ministry of Civil Aviation has taken a serious view of the incident.

Aviation Secretary Samir Sinha has asked Air India to take responsibility for the matter and said that anyone found guilty following the investigation would face action.

The government has also directed the DGCA to review existing drug-testing procedures for pilots and other aviation personnel.

The review is expected to examine whether mandatory screening procedures need to be strengthened and whether tougher penalties should be introduced for confirmed violations.

Authorities have also called for further assessment of cases where prescribed medicines could potentially affect test results.

Air India CEO Questioned

The incident comes at a time when the government is already increasing scrutiny of Air India's safety and operational practices.

Outgoing Air India CEO Campbell Wilson was summoned to the Ministry of Civil Aviation headquarters on Tuesday.

Officials reportedly questioned Wilson about the AI2379 incident and discussed broader safety and operational concerns involving the airline.

The meeting forms part of the government's wider review of Air India's operations as aviation authorities examine recent incidents involving the carrier.

DGCA Probe Underway

The DGCA investigation will determine the circumstances surrounding the flight, including the reported cockpit departure, the alleged attempt to smoke in the cabin and the pilot's reported drug-test result.

Investigators will also examine whether aviation regulations or airline safety procedures were breached.

Until the inquiry is completed, the allegations against the pilot remain subject to investigation. The final findings will determine whether disciplinary or regulatory action is warranted.

The investigation into the Air India Phuket-Delhi flight that suddenly lost around 300 feet of altitude on August 4 has shifted attention from initial speculation about turbulence and the pilot's drug test to a possible chain of technical failures involving the aircraft's hydraulic and flight-control systems.

Air India flight AI2379, an Airbus A320 carrying 137 passengers and crew, was flying towards New Delhi when the sudden altitude change occurred roughly two-and-a-half hours after departure from Phuket. The incident left 17 people injured and prompted a formal investigation by the Aircraft Accident Investigation Bureau (AAIB).

While the exact cause remains under investigation, reports citing sources familiar with the probe have pointed to triple hydraulic-system failures, an autopilot disconnect and other temporary system indications on board the aircraft.

What Happened Mid-Flight?

The aircraft had reportedly been flying normally before the sudden incident. Passengers described an abrupt disturbance followed by intense shaking and a rapid drop in altitude.

Some passengers reported that cabin baggage and other objects were thrown around during the episode. Crew members instructed passengers to fasten their seatbelts as the aircraft experienced the sudden change.

The aircraft subsequently continued its journey and landed in Delhi, where injured passengers and crew members received medical attention.

The AAIB is investigating the sequence of events under the applicable international aviation investigation framework.

Focus Turns to Hydraulic Systems

One of the most significant developments in the investigation is the reported failure of all three hydraulic systems.

Aircraft hydraulic systems use pressurised fluid to operate and assist several critical components, including flight-control surfaces and other mechanical systems. Modern commercial aircraft are designed with multiple levels of redundancy, making a simultaneous failure of all three hydraulic systems an unusual event.

According to reports citing aviation sources, the cockpit crew responded to the problem by manually controlling the aircraft and temporarily changing its flight path or altitude.

The reported 300-foot descent may therefore have been part of the crew's response to the technical problem rather than an uncontrolled plunge.

Why Did the Aircraft Lose Altitude?

The precise sequence remains unclear.

Reports indicate that the aircraft's autopilot disconnected during the incident, requiring the co-pilot to regain manual control. Several cockpit indicators or switches were also reportedly observed to change temporarily.

If confirmed by investigators, the combination of hydraulic-system problems and an autopilot disconnect could help explain why the aircraft experienced a sudden change in altitude.

However, investigators will need to establish whether the hydraulic failures occurred simultaneously, whether one system failure triggered another and how the aircraft's flight-control systems responded.

What About the Pilot's Drug Test?

The pilot's initial psychoactive-substance screening has also attracted attention.

The Civil Aviation Ministry said the initial screening produced a result that required further analysis and that a confirmatory test was being conducted. The final result had not been established at the time of the reports provided.

The Airline Pilots Association of India has also pointed out that some commonly used medicines can potentially affect preliminary screening results.

Therefore, the initial "non-negative" screening should not be treated as proof that the pilot was intoxicated or that it caused the altitude loss.

Investigators will have to consider the confirmatory test alongside cockpit recordings, aircraft data and other evidence.

Turbulence Theory Also Under Review

Turbulence was initially cited in Air India's description of the incident. However, subsequent statements reportedly did not place the same emphasis on turbulence.

This has raised questions about whether turbulence was actually responsible for the altitude loss or whether the aircraft's technical problems played the central role.

Only the formal investigation can establish whether turbulence, a technical malfunction or a combination of factors contributed to the event.

Airbus Joins the Investigation

Aircraft manufacturer Airbus is assisting the investigation.

The company has said it is providing technical assistance to the relevant authorities in accordance with ICAO Annex 13 and is sending specialists to support the probe.

Investigators are expected to examine the aircraft's flight-data recorder, cockpit voice recorder, maintenance records and relevant system data. These sources should help establish exactly what happened inside the aircraft during the critical seconds.

The investigation will also examine whether the reported hydraulic failures occurred before or after the altitude change and how the cockpit crew responded.

What Happens Next?

At this stage, several explanations remain possible, but none has been conclusively established.

The investigation will need to determine the relationship between the reported triple hydraulic failure, autopilot disconnect, cockpit indications, the aircraft's 300-foot altitude change and the injuries sustained inside the cabin.

The pilot's confirmatory test will also be important in determining whether the preliminary screening has any relevance to the incident.

Until the AAIB completes its investigation, claims that the aircraft plunged because of pilot intoxication or turbulence remain unproven.

For passengers, however, the incident has once again highlighted the importance of keeping seatbelts fastened throughout a flight, including when the aircraft appears to be flying normally.

An Air India flight travelling from Phuket to New Delhi experienced a sudden loss of approximately 300 feet in altitude during cruise, prompting a formal aviation-safety investigation and additional testing of the pilot-in-command.

The incident occurred on August 4 aboard Air India flight AI2379, operated by an Airbus A320 registered as VT-EXO. The aircraft stabilised after the altitude loss and later landed safely in Delhi.

According to the Ministry of Civil Aviation, the flight was carrying 137 passengers—including three infants—and eight crew members. A few passengers and cabin-crew members reportedly suffered injuries during the incident. The ministry did not disclose their condition or the exact nature of the injuries.

Initial Screening Not a Final Finding

Both pilots underwent the prescribed psychoactive-substance screening as part of the standard procedure followed after such incidents.

The pilot-in-command’s initial screening produced a result requiring confirmatory testing. Samples have been sent to a designated laboratory, and the final report is awaited.

The preliminary result must not be described as a confirmed positive drug test. The ministry has also not disclosed which substance, if any, may have been indicated.

The Directorate General of Civil Aviation has removed both pilots from the flying roster while the investigation continues.

AAIB Investigating ‘Serious Incident’

The occurrence has been classified as a “serious incident” and is being investigated by the Aircraft Accident Investigation Bureau.

Air India said it was aware that the pilots had undergone post-flight screening but had not been informed of the results. The airline said it would cooperate with the investigating authorities.

The investigation will examine the aircraft’s flight data, cockpit actions and possible technical or operational factors behind the sudden altitude loss.