New Delhi: Several technical and operational questions are being raised by various stakeholders from the aviation sector, as Airbus completed a preliminary probe into the Air India Phuket-New Delhi flight’s mid-air scare that injured 24 people last week.
A post-flight technical sheet and a preliminary Airbus assessment accessed by ThePrint show that the aircraft recorded multiple technical warnings around the incident, including low hydraulic pressure across all three hydraulic systems and a temporary loss of key flight-control surfaces.
The findings have emerged alongside the disclosure that the pilot-in-command (PIC) tested positive for psychoactive substances in both the initial and confirmatory tests, thereby putting the focus on two separate aspects of the pilot’s fitness to fly and what happened inside the aircraft.
Aviation experts say that in the absence of the airline coming out and clarifying what exactly transpired inside the Airbus A320neo, the ongoing situation raises questions over the opacity of the investigation process, the severity of the technical failure among others.
The Air India flight, carrying 137 passengers and eight crew members, was on its way to New Delhi on 4 August when it experienced the sudden loss of 300 ft altitude.
A dozen warnings
The post-flight technical sheet shows that the aircraft recorded 12 warning and failure messages around the time of the sudden mid-air altitude drop These included low-pressure warnings on its Green, Yellow and Blue hydraulic systems, an ‘AUTO FLT AP OFF’ alert, and faults involving both the left and right elevators.
The Airbus A320’s three hydraulic systems use pressurised fluid to operate important flight controls. The elevators control the aircraft’s pitch—whether its nose moves up (climb) or down (descent).
The ‘AUTO FLT AP OFF’ alert means the autopilot had disengaged. In simple terms, the system that was automatically maintain the aircraft’s flight path was no longer doing so and that the pilots had to control the aircraft manually.
The technical sheet recorded low reservoir levels in the Yellow and Blue hydraulic systems, an Engine 1 anti-ice fault and warnings related to the right door and aft emergency exits.
In its preliminary findings, Airbus found that the Green hydraulic system was lost shortly before 04:02:44 hours, followed about a second later by the Blue and Yellow systems. The loss of hydraulic pressure temporarily affected the aircraft’s elevators, ailerons and remaining spoilers for about four seconds.
During this period, Airbus said, the ailerons moved towards negative positions, causing the aircraft’s pitch to increase. Ailerons are hinged flight-control surfaces attached to the trailing edge of an airplane’s wings, used to control the aircraft’s roll and help it turn.
At about 04:02:46 hours, the autopilot disconnected and a full nose-down input was applied from the First Officer’s side, but there was initially no direct response from the flight-control surfaces, the report says. The hydraulic systems then recovered, allowing the flight-control surfaces to return to operation.
The flight-control behaviour, according to Airbus, was a consequence of the loss of hydraulic pressure. It also identified an issue involving the Green hydraulic pressure switch 1151GN — a component that monitors hydraulic pressure.
Air India was asked to conduct further tests of all three hydraulic systems, including their pressure switches and pressure transducers, which measure pressure in the system. Airbus has also sought records of hydraulic-system maintenance carried out during the previous month.
The Aircraft Accident Investigation Bureau (AAIB) has taken up the investigation, with technical assistance from Airbus and France’s Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA).
The AAIB has said it is examining the aircraft and its systems, recorded flight data, operational and maintenance records, medical information and human factors, besides interviewing people connected with the incident.
Another point of concern is when the 4th August episode is seen in the context of repetitive defects recorded across Air India’s fleet.
Government data tabled in the Lok Sabha in February 2026 showed that 137 of 166 Air India aircraft examined—about 82 percent—had been flagged for repetitive defects between January 2025 and 3 February 2026.
At that time, Air India had said the number was high because it had conducted checks across its fleet “out of an abundance of caution.”
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Decisions of pilot
Former pilots, meanwhile, have questioned why the aircraft continued to fly towards Delhi after the incident rather than diverting to a nearer suitable airport.
One of them alleged that the pilots should have been given the option of declaring an emergency and diverting after he made a Pan-Pan call—an international radio signal that means an aircraft has an urgent safety problem, but it is not in immediate danger.
Whether an emergency was declared, where the aircraft was when the altitude drop occurred, what instructions the crew received and why the decision was taken to continue to Delhi can be established through ATC (Air Traffic Control) recordings, flight data, crew accounts and operational records.
ThePrint has sought responses through email from Air India, AAIB, and France’s BEA. This report will be updated once a response is received.
PIC under the lens
The technical findings are unfolding alongside a separate investigation into the psychoactive-substance screening of the PIC. Both pilots of AI 2379 flight have been taken off the roster pending an inquiry.
The PIC’s initial screening required confirmatory testing, following which samples were sent to a designated laboratory. Sources told ThePrint that the PIC filed the initial test and that the confirmatory test was also positive.
A positive test does not by itself establish that the pilot was impaired during the flight or that the result had any connection with the altitude event. The timing, concentration and effect of any substance would have to be established separately.
Aviation consultant Sanjay Lazar said the pilot’s drug-test result and the aircraft’s technical problems should be treated as separate issues. “There are 2 parts to this onion – the ‘dope’ bit and the ‘technical failures’; both of them need to be looked at separately,” he posted on the social media platform X.
Questions for DGCA, Air India
The Airbus technical findings have also prompted questions from aviation insiders about what Air India and DGCA knew after the aircraft landed in Delhi.
Three industry insiders, including one formerly associated with the AAIB, questioned the handling of information following the incident.
One of them recalled that Air India’s engineering team downloaded the aircraft’s technical data after the flight and had access to the post-flight report and the pilot’s statement. “The engineering team downloaded this. Post-flight report, statement of the pilot. The DGCA was communicated promptly,” the insider alleged.
The insider also questioned why the initial account focused on turbulence if technical information was available to the airline and regulator.
Lazar also alleged that the DGCA had access to information about the 4 August incident but that it was not made public at the time. “ALL THESE FACTS WERE KNOWN TO THE REGULATOR @DGCAIndia ON 4 AUG. WE AS THE PUBLIC WERE MISLED INTO THE HOCUS POCUS OF CAT (turbulence) (sic),” he said on X.
(Edited by Tony Rai)
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