The Throttle Control Module (TCM) of the ill-fated Air India plane, which crashed near the Ahmedabad airport on June 12, was replaced by the airline twice in the last six years, following a directive from Boeing in 2019, news agency PTI quoted sources as saying.

The TCM includes fuel control switches, the ones that feed fuel into the aircraft’s engines, the focus of which was shifted in the ongoing probe into the crash.

The preliminary report on the crashed Air India plane, released by the Aircraft Accident Investigation Bureau (AAIB) on Saturday, noted that the TCM was replaced in 2019 and 2023.

However, it also stated that the TCM replacement was not linked to the fuel control switches.

According to PTI, sources said that a revised maintenance planning document (MPD) was issued by Boeing for all the operators of the Dreamliners in 2019, according to which, the operators have to change the TCM every 24,000 flight hours.

Specific details about the MPD could not be immediately ascertained, the report stated.

It also quoted an Air India spokesperson as saying that the airline was working closely with stakeholders, including regulators.

“We continue to fully cooperate with the AAIB and other authorities as their investigation progresses. “Given the active nature of the investigation, we are unable to comment on specific details and refer all such enquiries to the AAIB," the spokesperson said.

AIR INDIA CRASH PRELIMINARY REPORT

AAIB, in its report, mentioned that at this stage of the investigation, “there are no recommended actions to B787-8 and/or GE GEnx-1B engine operators and manufacturers".

Air India’s Dreamliner VT-ANB, which crashed on June 12, was powered by GEnx-1B engines.

According to the report, the FAA issued a Special Airworthiness Information Bulletin on December 17, 2018, regarding the potential disengagement of the fuel control switch locking feature.

“This SAIB was issued based on reports from operators of Model 737 aeroplanes that the fuel control switches were installed with the locking feature disengaged. The airworthiness concern was not considered an unsafe condition that would warrant an airworthiness directive by the FAA," it said.

AAIB also said the fuel control switch design, including the locking feature, is similar on various Boeing aeroplanes models, including part number 4TL837-3D, which is fitted in B787-8 aircraft VT-ANB.

“As per the information from Air India, the suggested inspections were not carried out as the SAIB was advisory and not mandatory. The scrutiny of maintenance records revealed that the throttle control module was replaced on VT-ANB in 2019 and 2023."

“However, the reason for the replacement was not linked to the fuel control switch. There has been no defect reported about the fuel control switch since 2023 on VT-ANB," the report stated.
After being in cut-off mode, the fuel control switches of the aircraft’s two engines were turned on late. Still, the London-bound aircraft could not get enough thrust and altitude before it crashed into a building in Ahmedabad, killing 260 people.