New Delhi: The Air India Phuket-Delhi flight that suddenly lost around 300 feet of altitude during cruise on August 4 reportedly suffered a rare triple hydraulic system failure, along with other technical glitches, according to reports citing aviation sources.
The incident involved Air India flight AI2379, operated by an Airbus A320 registered as VT-EXO. The aircraft was flying from Phuket, Thailand, to Delhi when it experienced a sudden altitude loss before the crew stabilised the aircraft and continued the flight safely to Delhi.
The incident is now being investigated as a serious aviation occurrence, with India’s Aircraft Accident Investigation Bureau (AAIB) examining the aircraft’s systems, flight data and cockpit recordings.
What Happened To The Air India Flight?
Flight AI2379 was cruising toward Delhi on August 4 when the aircraft suddenly lost approximately 300 feet of altitude.
The abrupt change caused passengers and crew members to be thrown around the cabin. Reports said at least 17 people were injured, including cabin crew members who suffered neck and spinal injuries. Reuters, citing earlier official figures, reported eight passengers and four crew members injured.
The aircraft subsequently stabilised and completed its journey, landing safely in Delhi.
Triple Hydraulic Failure Reported
One of the most significant revelations from the ongoing investigation is the reported failure of all three hydraulic systems on the Airbus A320.
Captain Sam Thomas, president of the Airline Pilots Association of India, told The New Indian Express that the pilot-in-command realised the aircraft had suffered a triple hydraulic system failure while the aircraft was approaching the Jharsuguda area.
According to Thomas, the hydraulic systems are critical to the operation of the aircraft’s flight controls and other functions.
An Airbus A320 has three independent hydraulic systems. A failure affecting all three systems is considered a rare event, making the reported malfunction a major focus of the investigation.
Why Are Hydraulic Systems Important?
Hydraulic systems play a crucial role in an aircraft’s operation.
On the Airbus A320, hydraulic power is used for several important aircraft functions, including components associated with flight controls.
The aircraft has three hydraulic reservoirs, with hydraulic lines connecting them to systems throughout the aircraft. The redundancy provided by multiple systems is designed to help the aircraft continue operating even if one system experiences a failure.
The reported simultaneous failure of all three systems therefore raises important questions for investigators about what triggered the malfunction and how the systems interacted with other technical problems during the flight.
Autopilot Also Disconnected
The hydraulic failure was not the only technical issue reported on the flight.
Sources cited by PTI and India Today said the aircraft also experienced an autopilot disconnect.
After the autopilot disconnected, the co-pilot reportedly took manual control of the aircraft. A flight-control stall warning then appeared, while several indicator switches briefly went off.
Investigators are examining the sequence of these events to determine whether the various technical problems were connected to the sudden loss of altitude.
Was Turbulence Responsible?
The incident was initially described by Air India as a brief episode of in-flight turbulence that resulted in a momentary change in altitude.
However, the airline’s subsequent statement described the event as a sudden loss of altitude during cruise, without using the word turbulence.
The change in description has added to questions surrounding the exact cause of the incident. Reports now indicate that investigators are examining technical failures alongside atmospheric conditions rather than assuming turbulence alone caused the altitude drop.
Pilots Taken Off Flying Duty
Both pilots of the flight were removed from the flying roster while the investigation continues.
The development came after mandatory psychoactive-substance screening conducted following the incident.
According to the DGCA, the initial screening of the pilot-in-command produced a result requiring further analysis. The sample was sent to a designated laboratory for confirmatory testing, and the final result was awaited.
Importantly, an initial screening result does not by itself establish confirmed drug use. Further action will depend on the laboratory result and the findings of the aviation investigation.
AAIB Leads Investigation
The Directorate General of Civil Aviation has classified the occurrence as a serious incident.
The Aircraft Accident Investigation Bureau is investigating the circumstances surrounding the altitude loss. Investigators have secured the aircraft’s Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR), which are expected to provide important information about what happened during the flight.
The investigation will examine:
- The reported triple hydraulic system failure
- The autopilot disconnection
- Flight-control warnings
- Other technical glitches reported during the flight
- Weather and turbulence conditions
- Pilot actions and cockpit communications
- Flight recorder data
- The sequence leading to the 300-foot altitude loss
Airbus And French Investigators To Assist
Airbus is sending specialists to assist the Indian investigation.
France’s Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA) is also expected to participate in the probe.
Airbus said it would provide technical assistance to the relevant investigating authorities and dispatch a team of specialists.
The involvement of both the aircraft manufacturer and French aviation investigators is expected to help authorities analyse the technical aspects of the incident.
What Investigators Will Look For
The key question is whether the hydraulic failures directly caused the aircraft’s sudden altitude loss or whether multiple independent technical and environmental factors combined to produce the incident.
Investigators will also need to establish the precise sequence of events.
Flight recorder information could help determine when the hydraulic problems began, when the autopilot disconnected, what warnings appeared in the cockpit and how the pilots responded.
The investigation may also provide information about whether the aircraft’s systems behaved as designed during the emergency.
Aircraft Landed Safely
Despite the sudden altitude loss and the technical problems reported during the flight, the pilots managed to stabilise the aircraft.
The A320 continued to Delhi and landed safely.
The reported injuries were primarily associated with the sudden movement of passengers and crew inside the cabin. The incident therefore highlights the potential consequences of even a relatively short-lived loss of altitude during cruise.
Investigation Still Underway
The triple hydraulic failure is currently a reported finding, not a final determination of the cause of the incident.
The AAIB investigation remains ongoing, and the final explanation will depend on technical examinations, flight recorder data, cockpit recordings and other evidence.
Until the investigation is completed, it would be premature to attribute the incident to a single cause.
