August 14, 2026: A preliminary technical assessment by Airbus has revealed that an Air India Airbus A320neo operating from Phuket to Delhi briefly lost normal control of key flight surfaces after all three of the aircraft’s hydraulic systems lost pressure during the flight. The aircraft subsequently dropped around 300 feet, leaving the pilots struggling to control it for approximately four seconds. The incident has raised fresh questions about the cause of the failure and the safety systems designed to protect aircraft from multiple-system malfunctions.
The incident involved Air India flight AI2379 on August 4. The aircraft was cruising towards Delhi when it suddenly experienced the loss of altitude. The aircraft later stabilised and landed safely in Delhi, but passengers and crew were injured during the sudden descent. Earlier reports put the number of injured at 24.
What happened to the Air India aircraft?
According to Airbus’ initial assessment of the aircraft’s flight-data recorder, the three hydraulic systems known as the Green, Blue and Yellow systems experienced a rapid loss of pressure. These systems are critical because they provide hydraulic power to important flight-control surfaces.
The simultaneous loss affected the aircraft’s elevators and ailerons, which are essential for controlling pitch and roll. For several seconds, pilot control inputs reportedly did not produce the expected response. The aircraft then lost approximately 300 feet of altitude before the hydraulic systems recovered and normal control returned.
The fact that all three hydraulic systems were affected makes the incident particularly unusual. Aircraft are designed with multiple independent systems precisely to provide redundancy if one system experiences a failure.
Why four seconds became critical
Four seconds may sound insignificant during a normal flight, but at cruising altitude and high speed, it can be extremely important.
The aircraft’s autopilot disconnected during the event, while the co-pilot reportedly applied nose-down control input after stall warnings were generated. The initial control response was limited because of the temporary hydraulic failure. Once hydraulic pressure returned, the pilots were able to regain control.
The incident therefore demonstrates how quickly a technical malfunction can become a serious flight-control emergency.
It also highlights the importance of the aircraft’s redundancy systems and the pilots’ ability to respond when automated systems suddenly become unavailable.
What caused the hydraulic failure?
This remains the biggest unanswered question.
Airbus’ preliminary assessment has identified what happened to the hydraulic systems, but it has not yet established the definitive root cause. Airbus has reportedly requested detailed maintenance information from Air India as part of the continuing investigation.
A possible faulty pressure sensor has been raised in reporting, but that should not yet be treated as the confirmed cause of the incident. The investigation will need to establish whether the pressure loss resulted from a sensor problem, a mechanical failure, an electrical issue, a combination of faults or another technical factor.
That distinction is important because the current Airbus assessment is preliminary.
Why the incident matters for aviation safety
Modern commercial aircraft are designed with multiple layers of redundancy. The A320 family, like other commercial aircraft, does not depend on a single hydraulic system for all flight-control functions.
The simultaneous loss of pressure across all three systems is therefore an event that requires detailed technical examination.
The investigation will need to determine how apparently independent systems were affected at almost the same time and whether there was a common underlying factor.
That answer could have implications beyond Air India if the investigation identifies a component or system-level issue that could potentially affect other aircraft.
Airbus and Indian investigators are examining the incident
The investigation is being conducted with assistance from Airbus and other aviation authorities. India has secured the aircraft’s flight-data recorder and cockpit voice recorder as part of the investigation into the incident.
The Aircraft Accident Investigation Bureau is also examining the circumstances surrounding the sudden altitude loss.
Investigators are expected to combine flight-recorder information with maintenance records, aircraft technical data and crew accounts.
This process is important because flight-data recordings can show what the aircraft systems did, but investigators still need to determine why the systems behaved that way.
Pilot factors are also being examined separately
The technical findings come amid a separate investigation into the flight crew.
Reuters has reported that the captain’s confirmatory drug test was positive for marijuana following the incident, while both pilots were removed from duty pending the investigation. The aviation authorities are examining the matter separately from the aircraft’s technical malfunction.
It is important not to automatically connect the two issues.
The Airbus assessment identifies a serious hydraulic-control event, while the investigation into the pilot’s test results concerns crew fitness and operational factors.
Authorities will ultimately have to establish whether, and to what extent, different factors contributed to the incident.
The bigger question is aircraft redundancy
The most important technical question emerging from the incident is whether the aircraft’s multiple hydraulic systems can be sufficiently isolated from one another.
Redundancy is one of the foundations of commercial aviation safety. A failure in one system should ideally not remove the aircraft’s ability to maintain controlled flight.
The temporary loss of all three systems therefore makes this incident particularly important from an engineering perspective.
If investigators discover a common failure mechanism, aircraft operators and manufacturers may need to examine whether similar aircraft could be exposed to the same risk.
Conclusion
The Air India Phuket-Delhi incident has moved beyond an initial report of turbulence or a sudden altitude loss. Airbus’ preliminary assessment indicates that the A320neo experienced a rare simultaneous loss of hydraulic pressure across all three systems, temporarily affecting important flight controls for around four seconds.
The aircraft ultimately recovered and landed safely, but the incident resulted in injuries and has triggered a detailed technical investigation.
The most important question now is not simply why the aircraft dropped 300 feet. It is why three hydraulic systems that are designed to provide redundancy were affected during the same event.
Until investigators establish the root cause, it would be premature to draw final conclusions about the aircraft, maintenance procedures or crew performance.
What the incident does demonstrate is the importance of continuous monitoring, independent safety systems and rapid investigation when a modern commercial aircraft experiences an unusual loss of flight-control capability.
