Abu Dhabi-Hyderabad Etihad Boeing 787: No issue with fuel control switches, return flight was precautionary; inspection followed Air India crash preliminary report | Mumbai News
MUMBAI: An Etihad Airways Boeing 787 returned to Abu Dhabi shortly after take-off for Hyderabad on Sunday, following which the airline carried out an inspection of the aircraft’s fuel control switch locking mechanism as part of an engineering work order. On Thursday, the airline said the pilots decision to return was a precautionary measure. The locking mechanism of fuel control switches on Boeing aircraft is under global scrutiny after it was mentioned in the preliminary report on the June 12 Air India AI-171 Boeing 787 accident which killed 270 people.On Monday, in a statement to the Times of India on a query about the said engineering work order, the airline said: “Etihad always ensures its maintenance is fully compliant.”On Thursday, Etihad updated its statement. “Etihad has not experienced any issues with fuel control switches. The return of flight EY352 on 13 July was a precautionary measure and not related to the aircraft’s fuel system,” the airline said. The said aircraft (A6-BLI) took off and climbed to about 9500 feet when the pilots diverted it back to Abu Dhabi. TOI had reported that since the aircraft operated a flight on Monday, it is unlikely that a problem was detected in the locking mechanism. India’s Aircraft Accident Investigation Bureau (AAIB) released the preliminary report into AI 171 accident on Saturday, July 12. The Etihad engineering work order came a day later, on July 13. TOI had accessed the said document, it instructs engineers to inspect whether the locking mechanism on the fuel control supply switches in the said Boeing 787 aircraft can be moved without lifting.Why is this particular locking feature on Boeing aircraft in focus now?The AAIB report said that fuel control switches on Air India B787 transitioned from “Run’’ to ‘’Cutoff”’ three seconds after the aircraft lifted off from Ahmedabad runway. “In the cockpit voice recording, one of the pilots is heard asking the other why did he cut off (the fuel supply). The other pilot responded that he did not do so”, the report said.Fuel control switches have a locking mechanism to prevent inadvertent movement from “Run”, which starts and continues the fuel supply to “Cutoff” which discontinues the fuel supply or vice-versa. The switch has to be lifted and then moved forward where it drops into a slot and this starts the fuel supply. Similarly, to cut the fuel supply the switch has to be lifted and pulled back into a slot. But a faulty lock can be moved without lifting and so can inadvertently move during different stages of flight, such as a take-off for instance.The AAIB report referred to a 2018 safety bulletin issued by the US aviation regulator which instructed airlines to inspect for locking system failure in the fuel control switches of Boeing aircraft, including Boeing 787. A faulty locking system could cut off fuel supply to the engines without pilots input. The AAIB report said that Air India did not carry out the inspection as it was not mandated by the FAA.The Etihad engineering work order follows the 2018 directive issued by the Federal Aviation Administration (FAA). “If the switch cannot be moved without lifting, the locking feature is functional. No further action is needed. If the switch can be moved freely without lifting, the locking feature has failed or is disengaged. Replace the Thrust Control Module (TCM)”, said the Etihad work order.
