2 days ago
Airlines initiate locking mechanism checks in Boeing 787 aircraft fuel switches
The identification in the preliminary report of fuel being cut off to both engines shortly after take off as the cause of the Air India plane crash in Ahmedabad last month has prompted airlines to issue directives for checking the locking mechanism in the fuel switches of Boeing 787 aircraft. AAIB's report into the Air India plane crash said fuel control switches were found in the 'cutoff' position. (REUTERS)
The Aircraft Accident Investigation Bureau (AAIB)'s report into the crash, released on Saturday, said fuel control switches were found in the 'cutoff' position. The report triggered a debate over whether pilot action or mechanical failure caused the crash, which left 260 people dead. It said that there was no 'recommended action' for either Boeing, the maker of the aircraft, or GE, the engine manufacturer, at this time.
Against the backdrop of the report, Etihad Airways, one of the United Arab Emirates two flag carriers, asked its engineers to inspect the locking mechanism of the fuel control switches in the B-787 aircraft. It asked them to be careful while operating the switches.
The fuel control switch is a key cockpit component pilots use to start or stop fuel supply to an engine. It includes a locking feature that requires the pilot to lift the switch before moving it to avoid accidental operation.
In its safety circular or 'standard work package' for its engineering team, a copy of which was posted on X, the Etihad asked them to fully inspect the fuel control switch locking feature for 'proper engagement'. 'Attempt to gently move (without applying excessive force) the Left (L) fuel control switch on the P10 Control Stand from 'CUTOFF' to 'RUN' without lifting the switch,' the circular said. 'If the switch cannot be moved without lifting, the locking feature is functional. No further action is required. Proceed to the next step.'
HT has reached out to the airline for comments on the circular.
The AAIB said that the Air India plane's engine 1 and engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec. 'In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so'.
The 15-page report was published a month after the disaster. It provided the first official account of India's worst aviation accident in decades. The report cited data from the black boxes.
The crew restored fuel flow within 10 and 14 seconds, triggering automatic engine restart sequences, but the Boeing 787 had already begun its irreversible descent toward a medical college hostel in Ahmedabad.
Civil aviation minister Ram Mohan Naidu urged caution and called for waiting for the final report. The investigation into the plane crash is still on.
On Saturday, the US Federal Aviation Administration (FAA) cited the AAIB's preliminary report regarding potential disengagement of the fuel control switch locking feature on Boeing Model 737 air planes. It said that this was based on reports that the fuel control switches were installed with the locking feature disengaged. The FAA added that although the fuel control switch design, including the locking feature, is similar on various Boeing air plane models, the FAA does not consider this issue to be an unsafe condition that would warrant an Airworthiness Directive on any Boeing air plane models, including the Model 787.
The FAA said it will continue to share relevant information with foreign civil aviation authorities. It noted the AAIB continues to lead the accident investigation, with the FAA providing technical support.
The AAIB report referred to the FAA's Special Airworthiness Information Bulletin on December 17, 2018, warning aircraft operators of a potential issue involving the locking mechanism on engine fuel control switches in Boeing aircraft models, including the Boeing 787-8.
The SAIB said that the issue affects Boeing models, including the 717, 737, 747, 757, 767, and 787 series. It issued a bulletin to check whether the switch moved freely without lifting and replacing the switch if the locking mechanism was found disengaged. It did not make it mandatory for the airline operators to conduct the checks and asked them to report any failure of the locking mechanism to Boeing with relevant aircraft and part details.
The preliminary crash report said that Air India did not perform the inspections. The Indian aviation regulator, the Directorate General of Civil Aviation (DGCA), has not issued any directive. Officials said the DGCA was reviewing the situation and is likely to make a decision soon.
