Air India Phuket–Delhi flight: Cascade of tech failures preceded 300-ft plunge, not turbulence, sources say
The Phuket–Delhi flight that experienced a “momentary loss in altitude” on August 4, injuring 17 people on board, was preceded by a cascade of failures
The Phuket–Delhi flight that experienced a “momentary loss in altitude” on August 4, injuring 17 people on board, was preceded by a cascade of failures involving the aircraft’s hydraulic and flight-control systems, according to multiple sources familiar with the matter, contradicting the airline’s initial attribution of the incident to turbulence. Nearly 2.5 hours after taking off from Phuket at 6.56 a.m., Air India flight AI 2379 operated on Airbus A320 neo was hit by a cascade of technical failures at 9.32 a.m. IST, involving the aircraft’s hydraulic and flight-control systems. The sequence involved low-pressure indications and failures affecting one or two hydraulic systems at a time, with different combinations appearing as the failures cascaded. This was followed by an autopilot disconnect and simultaneous fault indications affecting both the left and right elevators, which are the control surfaces that move the aircraft’s nose up or down.
Automated post-flight maintenance report The A320 neo has three independent hydraulic systems that power critical functions including the primary flight controls, landing gear, nose-wheel steering, thrust reversers, flaps and slats, and braking systems. The automated post-flight maintenance report records failures and warning indications in different hydraulic systems, occurring either individually or in combinations of two systems, according to a source who has seen a copy of the report. The report records nine such fault messages within one minute. As the aircraft pitched up and a stall warning was triggered, one of the pilots took manual control and attempted to push the nose down, according to another Air India source familiar with the sequence of events. The pilot may have applied significant control input while attempting to recover the aircraft, the source said, causing the aircraft to lose around 300 feet of altitude in a matter of moments and throwing passengers and crew upward.
The available technical records do not show further fault messages after this sequence. Sources said this indicates that the flight-control systems were recovered following the pilots’ intervention, although the precise relationship between the technical failures, the flight-control response and the subsequent altitude excursion remains subject to investigation. The pilots decided to continue to Delhi rather than divert to a nearby airport due to the availability of better medical facilities for the injured passengers as well as aircraft engineering support. While the Ministry of Civil Aviation said in a press statement that the pilot-in-command’s psychoactive substance screening test requires confirmatory testing, the result of which is awaited, sources said the commander was not at the controls when the incident occurred and had momentarily left his seat. The incident has been classified as a serious incident and is being investigated by the Aircraft Accident Investigation Bureau (AAIB).
The BriefWire