After pilot flags possible defect, Air India initiates precautionary inspection of Boeing 787 fuel control switches

Engine fuel control switches have been at the focus of the investigation into the fatal crash of an Air India Boeing 787 jet in Ahmedabad in June last year, with the preliminary probe report saying that the accident occurred after both engines of the ill-fated aircraft were starved as both its fuel control switches transitioned from RUN to CUTOFF position within a second of each other moments after lift-off.

According to sources aware of the matter, Air India’s Senior Vice President for Flight Operations Manish Uppal informed the airline’s Boeing 787 pilots that while the issue had been escalated to Boeing for priority evaluation, in the interim, the airline’s engineers have started a precautionary inspection.

“…while we await Boeing’s response, our engineers–out of abundance of caution–have initiated precautionary fleet-wide re-inspection of the Fuel Control Switch (FCS) latch to verify normal operations. To date, no adverse findings have been reported on the aircraft for which this re-inspection is completed,” Uppal’s communication to pilots read, it is learnt.

He further reminded the pilots to promptly report any defects observed during operations and to ensure that all required actions are completed before they accept the aircraft for operating a flight. The spring-loaded switches have a locking mechanism that requires the pilots to pull the switch up before moving it between either of its two positions—RUN and CUTOFF.

“We are aware that one of our pilots has reported a possible defect on the fuel control switch of a Boeing 787-8 aircraft. After receiving this initial information, we have grounded the aircraft and are involving the OEM (original equipment manufacturer) to get the pilot’s concerns checked on a priority basis. The matter has been communicated to the aviation regulator, DGCA. Air India had checked the fuel control switches on all Boeing 787 aircraft in its fleet after a directive from the DGCA, and had found no issues. At Air India, the safety of our passengers and crew remains top priority,” an Air India spokesperson had said on Monday.

The airline did not provide details regarding the likely defect reported by the pilot. The OEM for the aircraft is Boeing, while the fuel control switch manufacturer is Honeywell. “We are in contact with Air India and are supporting their review of this matter,” Boeing said on Monday.

According to a statement by aviation safety advocacy group Safety Matters Foundation, the crew of the Boeing 787 reported abnormal behaviour of the left engine fuel control switch on Monday, as during engine start, the switch failed to remain locked in the RUN position on two attempts, moving towards CUTOFF. These switches control the flow of fuel to the aircraft’s engines, and such a malfunction could lead to inadvertent engine shutdown under specific conditions, Safety Matters Foundation said.

In 2018, the US Federal Aviation Administration (FAA) had issued an information bulletin on the potential disengagement of the switch locking mechanism on certain fuel control switches on Boeing aircraft, including those on Boeing 787s. The FAA had advised airlines to inspect the fuel control switches, but as the bulletin was advisory and not mandatory, a number of airlines—including Air India—had not done the inspections at the time. However, after the crash of Air India flight AI-171 last June, India’s aviation regulator Directorate General of Civil Aviation (DGCA) had ordered fuel control switch inspections on almost all Boeing aircraft in India.

Identifying the transitioning of the fuel control switches to CUTOFF from RUN as the reason behind the AI-171 crash, which claimed 260 lives, the Aircraft Accident Investigation Bureau’s (AAIB) preliminary report mentioned that in the cockpit voice recording, one of the pilots was heard asking the other why he cut off the fuel, to which the other pilot responded saying he did not.

There has been considerable speculation on whether the switches were flicked by one of the pilots—inadvertently or otherwise—or whether the transition signal to the system was due to any technical, mechanical, or software issue. To be sure, the report does not state that either of the pilots physically moved the switches, just that they transitioned from RUN to CUTOFF. The investigation into the crash is ongoing, with the final probe report expected in a few months. According to the government, all possible angles and causes are being thoroughly investigated by the AAIB.