AAIB links Air India altitude upset to temporary three-system hydraulic loss
ಕನ್ನಡ version is not ready yet. Showing English.
Where it stands
Air India flight AI2379 from Phuket to Delhi suffered an altitude upset on 4 August 2026. The Airbus A320 briefly lost pressure in all three hydraulic systems while cruising at 36,000 feet. The autopilot disconnected. A stall warning lasted two seconds. The aircraft first climbed 372 feet and then fell 292 feet from its assigned altitude. All three systems recovered within seconds. Twenty-four people received medical help. Four had serious injuries. AAIB published preliminary findings on 4 September. The final cause remains under investigation.
Background
Aircraft hydraulic systems use pressurised fluid to move important flight controls. The Airbus A320 has separate green, blue and yellow systems. Each system has its own reservoir and pressure sources. Separation provides redundancy when one system fails. AAIB investigates civil aircraft accidents and serious incidents in India. AAIB investigations seek to prevent recurrence. The investigation does not decide criminal or civil liability.
How it developed
-
4 August 2026How it started
Air India flight loses altitude during cruise and lands safely in Delhi
Flight AI2379 left Phuket for Delhi on 4 August 2026. The aircraft suffered an altitude upset inside the Kolkata flight information region. The aircraft stabilised and continued to Delhi. The aircraft landed safely. Medical teams assisted 24 passengers and crew members. Four people had serious injuries. AAIB classified the occurrence as an accident and opened an investigation.
-
Preliminary report released 4 September 2026New fact
Preliminary report records temporary pressure loss in all three hydraulic systems
AAIB released its preliminary report on 4 September 2026. The green hydraulic system first lost pressure at 09:32:43 IST. The blue and yellow systems followed four seconds later. The autopilot disconnected. A two-second stall warning followed. All three systems recovered within seconds. The report records no adverse weather report from the crew or air traffic control. The report also records a non-negative psychoactive-substance test for the pilot-in-command. AAIB recommended priority action by DGCA to prevent substance abuse. AAIB has not identified the probable cause.
Why it matters for UPSC
For GS3, connect aviation technology with safety regulation. Separate the occurrence, evidence and cause. AAIB documented temporary hydraulic-pressure loss. AAIB issued one interim safety recommendation about psychoactive-substance abuse. AAIB did not state that the drug finding caused the hydraulic event. No adverse weather was reported by the crew or air traffic control. The final report may change the preliminary findings.
Key terms
Sources (5)
- Ministry of Civil Aviation · official · Sudden loss of altitude during cruise and injuries on Air India A320 flight AI23794 Sep, 9:00 pm
- Bureau of Enquiry and Analysis for Civil Aviation Safety · official · Accident to Airbus A320 VT-EXO operated by Air India on 4 August 20264 Sep, 9:00 pm
- Aircraft Accident Investigation Bureau · official · Preliminary report on Air India A320 VT-EXO flight AI2379 on 4 August 20264 Sep, 9:00 pm
- Business Standard · Triple hydraulic loss, no adverse weather on Air India flight: AAIB4 Sep, 9:00 pm
- The Indian Express · Air India Phuket-Delhi incident: AAIB report flags hydraulic failure and pilot drug test4 Sep, 9:00 pm