FAA Warned In 2018 Of Boeing Engine Shutdown Risk But Air India Ignored Fuel Switch Advisory

News18

12-07-2025

Last Updated:
To move the switch from one position to the other where the locking feature is engaged, it is necessary for the pilot to lift the switch up while transitioning the switch position
Did the fuel control switch in the ill-fated Air India 171 Boeing aircraft malfunction because it was disengaged and not locked? The preliminary inquiry report into the incident points to an FAA warning in 2018 that said inadvertent operation of the switch could result in an unintended consequence, such as an in-flight engine shutdown. But the report has stopped short of blaming this as the cause for the crash.
CNN-News18 has accessed the 2018 warning by Federal Aviation Administration (FAA) that Boeing received reports from operators of Model 737 airplanes that the fuel control switches were installed with the locking feature disengaged.
The fuel control switches (or engine start switches) are installed on the control stand in the flight deck and used by the pilot to supply or cut off fuel to the engines. The fuel control switch has a locking feature to prevent inadvertent operation that could result in unintended switch movement between the fuel supply and fuel cut-off positions.
To move the switch from one position to the other under the condition where the locking feature is engaged, it is necessary for the pilot to lift the switch up while transitioning the switch position.
'If the locking feature is disengaged, the switch can be moved between the two positions without lifting the switch during transition, and the switch would be exposed to the potential of inadvertent operation. Inadvertent operation of the switch could result in an unintended consequence, such as an in-flight engine shutdown," the FAA warning said.
'While the airplane is on the ground, check whether the fuel control switch can be moved between the two positions without lifting up the switch. If the switch can be moved without lifting it up, the locking feature has been disengaged and the switch should be replaced at the earliest opportunity," the FAA said.
For Boeing Model 737-700, -700C, -800, and -900ER series airplanes and Boeing Model 737-8 and -9 airplanes delivered with a fuel control switch having P/N 766AT613-3D, it was advised that the fuel control switch be replaced with a switch having P/N 766AT614-3D, which includes an improved locking feature.
Was this Done?
The AAIB report says that the fuel control switch design, including the locking feature, is similar on various Boeing airplane models including part number 4TL837-3D which is fitted in B787-8 aircraft VT-ANB that crashed in Ahmedabad.
'As per the information from Air India, the suggested inspections were not carried out as the FAA directive 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 pertaining to the fuel control switch since 2023 on VT-ANB," the AAIB report says.
What Happened on AI-171
After the AI-171 aircraft achieved the maximum recorded airspeed of 180 Knots, immediately thereafter, the Engine 1 and Engine 2 fuel cut-off switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec, says the AAIB report.
The Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cut off.
'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 report says. The pilots then tried to restart the engines—but it was too late.
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