What is aircraft's fuel switch? Did it cause Air India crash or is US shielding Boeing, blaming pilots?

After the Aircraft Accident Investigation Bureau (AAIB) reported that the pilots somehow switched off the fuel battery, causing the Air India crash, the moot question that cropped up is- what is a fuel switch and how does it work? The fuel control unit is a vital part of an aircraft that acts as a computer to determine the amount of fuel needed to deliver the power requested by the operator. When activated, the switch keeps fuel from being pumped into the system to minimize the risk of fire in case the system has developed a leak. 

How does fuel switch work?

Once it is triggered, it must be reset manually by pushing a button on top of the device, which restores current to the fuel pump. It must be reset manually by pushing a button on top of the device, which restores current to the fuel pump. Besides, a fuel lock is a fuel pump locking PIN pad device that provides powerful online reporting of the operation. Fuel Lock secures the fuel and allows the pilot to view usage reports from a web dashboard or through a mobile app.

AAIB Report

However, the controversy erupted Saturday after the AIIB said in its report that the cockpit voice recorded one pilot asking the other why he "did the cut-off", to which the other replies that he didn't. The report also says that the switches were moved to "run" position, but the plane crashed within seconds. It was also said in the report that seconds after take-off, both of the Boeing 787 Dreamliner's fuel-control switches moved to the "cut-off" position, starving the engines of fuel. 

ICPA rejects report

Rejecting the report, Indian Commercial Pilots' Association (ICPA) said the crew "acted in line with their training and responsibilities under challenging conditions and the pilots shouldn't be vilified based on conjecture". Meanwhile, the US Federal Aviation Administration (FAA) said the fuel control switches in Boeing aeroplanes were safe. It also noted that its own 2018 advisory "was based on reports that the fuel control switches were installed with the locking feature disengaged". It added that it did not believe this made the planes unsafe.