Archive · 5 Sep 2026
AAIB Probe Finds Triple Hydraulic Failure on Air India Flight
An Air India plane flying from Phuket to Delhi had a sudden problem with all three of its hydraulic systems.
These systems help move important flight controls.
The autopilot switched off, and the plane briefly gave a stall warning.
It first went higher and then dropped about 292 feet.
The hydraulic systems began working again within seconds, and the pilots landed safely in Delhi.
Because the seat-belt signs were off, 24 people were injured during the sudden movement.
Most reports say the pilot-in-command, or PIC, had a non-negative result for a psychoactive substance, while the co-pilot tested negative.
One article incorrectly described the co-pilot as the pilot who tested positive, so the reports conflict on that detail.
Investigators have not said that the test caused the aircraft’s technical problem, and the investigation is still continuing.
Air India flight AI-2379/A12379 lost its green, blue and yellow hydraulic systems within seconds while cruising at 36,000 feet from Phuket to Delhi on August 4.
The failure disconnected the autopilot, triggered a brief stall warning and caused the aircraft to climb 372 feet before descending 292 feet.
All hydraulic systems recovered within seconds, and the aircraft landed safely at Delhi’s Indira Gandhi International Airport.
Twenty passengers and four cabin crew members were injured; reports differ on hospitalization figures, with one account saying four were hospitalized and another saying 17 of 24 were hospitalized.
The AAIB is examining the hydraulic failure, an earlier PTU-related MEL item, maintenance records and pilot testing; the PIC tested non-negative, while the co-pilot tested negative.
- Who
- Air India flight AI-2379/A12379, an Airbus A320 aircraft carrying 137 passengers, six cabin crew members and two pilots.
- What
- The aircraft experienced a near-simultaneous loss of all three hydraulic systems, an autopilot disconnect, a brief stall warning, an altitude upset and 24 reported injuries.
- When
- August 4, at about 09:32 India time, while cruising at 36,000 feet.
- Where
- The flight was traveling from Phuket to Delhi in the Kolkata Flight Information Region and landed at Delhi’s Indira Gandhi International Airport.
- Why
- The definitive cause has not been established; the AAIB is examining technical, maintenance and other operational factors.
Initial and Conflicting Accounts
AAIB Preliminary Findings
Nature of the event
Initial and Conflicting Accounts
The government and Air India initially attributed the aircraft’s movement to severe turbulence; some reports described the occurrence as a sudden altitude drop.
AAIB Preliminary Findings
The AAIB later treated the occurrence as an accident and focused on the near-simultaneous loss of the green, blue and yellow hydraulic systems. It said neither the pilots nor air traffic control reported adverse weather.
Identity and meaning of the drug-test result
Initial and Conflicting Accounts
One article’s headline attributed the positive test to the co-pilot, while another report said sources identified the substance as marijuana and described the PIC as testing positive.
AAIB Preliminary Findings
The AAIB preliminary report identifies the PIC as non-negative in both initial and confirmatory testing, while the co-pilot tested negative. The report did not name the substance or establish that it affected the flight.
Hospitalization and pilot employment
Initial and Conflicting Accounts
Reports differ on the medical outcome: one says four people were hospitalized, while another says 17 of the 24 injured people were hospitalized. One report also says Air India terminated the PIC’s services.
AAIB Preliminary Findings
The AAIB account cited in other reports says 20 people received medical assistance, 20 were discharged after initial treatment and four with serious injuries were hospitalized. The investigation remains focused on determining causes and contributing factors rather than assigning blame.
- Flight
- Air India flight AI-2379, also identified as A12379, operating from Phuket to Delhi
- Aircraft
- Airbus A320neo/A320-251N, registration VT-EXO
- People on board
- 145: 137 passengers, six cabin crew members and two pilots
- Hydraulic sequence
- The green system failed first, followed four seconds later by the blue and yellow systems; all recovered shortly afterward
- Aircraft movement
- The aircraft climbed 372 feet and then descended 292 feet from flight level 360
- Injuries
- Twenty passengers and four cabin crew members were injured; hospitalization figures differ among reports
- Pilot testing
- The PIC’s initial and confirmatory tests were reported as non-negative for a psychoactive substance; the co-pilot tested negative
- Investigation status
- The AAIB preliminary report identified no definitive cause; hydraulic components, flight-recorder data and records remain under examination
Sources
AI Phuket fiasco: AAIB report flags hydraulic failure, pilot's drug test
Air India Phuket-Delhi incident: AAIB initial report flags hydraulic failure, pilot’s drug test
Air India Phuket flight suffered triple hydraulic failure; AAIB flags pilot’s drug test
Air India Phuket-Delhi Flight probe: Preliminary report reveals hydraulic failure and pilot's positive drug test
Air India Phuket-Delhi flight’s plunge linked to hydraulic failure: Pilot who failed drug test sacked
