DGCA investigates ‘uncommanded’ RAT deployment on Air India's Boeing 787-8 Dreamliner flight to Birmingham

The Directorate General of Civil Aviation (DGCA) is investigating a major safety incident where an Air India flight to Birmingham, UK, deployed its Ram Air Turbine (RAT) without command.

The plane, a Boeing 787-8 Dreamliner aircraft, reportedly deployed its RAT system — usually used in case of engine failure, minutes before landing at the airport on October 4, according to a PTI report.

What is RAT in planes?

RAT is generally automatically deployed in the eventuality of a dual engine failure or electrical/electronic or hydraulic failure, among others. It uses wind speed to generate emergency power.

DGCA investigation: What we know

While the plane landed safely, according to officials on October 5, the aviation watchdog is investigating the incident on aircraft VT-ANO operating the flight AI117 from Amritsar to Birmingham on October 4, the report said.

The incident has raised red flags for safety, and the Federation of Indian Pilots (FIP) has urged the DGCA to thoroughly check and investigate the electrical system of all Boeing 787 aircraft in the country.

Currently, there are 33 Boeing 787s, also known as Dreamliners, with Air India. IndiGo also operates the aircraft that has been taken on lease.

Notably, this apparent malfunction assumes significance after an Air India Dreamliner crashed on June 12 minutes after take off, killing 260 people.

A senior DGCA official told PTI that RAT got deployed during landing of the plane at 400 feet but the pilot did not report any related abnormality. “The maintenance actions for uncommanded RAT deployment recommended by Boeing have been carried out and no discrepancy were observed, the official said and added that the aircraft is being released for service,” the official said.

They added that a detailed investigation will be be carried out.

What has Air India and Boeing said?

In a statement on October 5, an Air India spokesperson said the operating crew of flight AI117 from Amritsar to Birmingham on October 4 detected deployment of RAT of the aircraft during its final approach.

“All electrical and hydraulic parameters were found normal, and the aircraft performed a safe landing at Birmingham,” the airline said but did not share specific details, including the number of people who were onboard the plane.

There was no comment from Boeing on the latest incident involving the Air India plane, according to PTI.

Pilots group raises red flag over safety concerns

Meanwhile, in a letter to the DGCA, pilots' grouping FIP on October 5 said the RAT was deployed automatically from the Air India's Dreamliner aircraft at around 500 feet on approach to Birmingham.

"The Aircraft Health Monitoring (AHM) has picked up a fault of the Bus Power Control Unit (BPCU) which may have caused the auto deployment of RAT," the pilots' grouping said. BPCU manages an aircraft's electrical power system.

"There have been numerous incidents on B787 aircraft. We have strongly taken up with the Civil Aviation Ministry and Aircraft Accident Investigation Bureau (AAIB) to thoroughly check the electrical system of all B787 aircraft in the country.

“After the Air India 171 crash, the FIP has been constantly insisting on thorough check up of the electrical system of B-787 aircraft in the country. Subsequent to the crash, DGCA checked only the fuel control switches of B-787 in Air India (fleet),” the pilots' body said in the letter.

(With inputs from PTI)