Preliminary findings into last month’s Air India plane crash suggest the aircraft’s fuel control switches were turned off, causing a loss of engine thrust shortly after takeoff.

Boeing and the United States Federal Aviation Agency (USFAA) recently notified that the fuel switch locks used in flight are safe, as per a report from Reuters. This comes at a time when the fuel switch lock mechanics have come under scrutiny amid the ongoing investigation into the Air India AI 171 crash.

Authorities released a preliminary report on the Air India crash, following an investigation. The London-bound flight from Ahmedabad crashed minutes into the June 12 flight. Only one passenger of the 242 passengers and flight crew survived.