An Air India Boeing 787-800, registration VT-ANE performing flight AI-380 from Delhi (India) to Singapore (Singapore) with 206 passengers and 10 crew, was enroute at FL390 about 210nm northwest of Kolkata (India) when the crew reported smoke in the cabin and decided to divert to Kolkata, where the aircraft landed safely about 45 minutes later.
A replacement Boeing 787-800 registration VT-ANS continued the flight and reached Singapore with a delay of 20.5 hours.
The airline confirmed the aircraft diverted to Kolkata and was declared AOG due to a technical issue. The passengers were taken to hotels and continued the flight the following day.
The occurrence aircraft was still on the ground in Kolkata about 25 hours after landing.
On Jul 6th 2020 India's DGCA released their final report (editorial note: India's DGCA have broken all links to previously released reports and no longer permit to directly link to their reports, hence we now link the report as released on Jul 6th 2020 via our site).
The report concludes the probable cause of the incident was:
CAC (Cabin Air Compressor) surge resulted in burn/overheat of CAC inlet Y-Duct, inlet housing and interfacing boot leading to smoke and acrid smell in the cockpit and cabin.
The DGCA summarized: "Post landing, during inspection of aircraft in LH Air conditioning bay, the AME observed Left CAC (Cabin Air Compressor) inlet Y-Duct, inlet housing and interfacing boot damaged and torn with burn and overheat signs. Post rectification action at Kolkata, the aircraft was released under MEL to Mumbai for detailed maintenance action."