- By Supratik Das
- Sat, 12 Jul 2025 08:40 AM (IST)
- Source:JND
Air India Crash report: Investigators probing the tragic crash of the Boeing 787 Dreamliner that killed 260 people have fixed their attention on the plane's engine fuel control switches, which had been inexplicably set to the 'CUTOFF' position seconds after departure, depriving both engines of fuel. Air India's nearly 12-year-old Boeing 787-8 aircraft, VT-ANB, en route to London Gatwick, crashed soon after takeoff into the residential quarters of BJ Medical College in Ahmedabad on June 12.
In its 15-page initial report of the crash that occurred within about 30 seconds after the plane had taken off, the Aircraft Accident Investigation Bureau (AAIB) on Saturday reported that the fuel control switches were activated later, but the deceleration in one of the engines was unavoidable. According to the EAFR, the engine 1 fuel cutoff switch went from CUTOFF to RUN at approximately 08:08:52 UTC. Then at 08:08:56 UTC, the engine 2 fuel cutoff switch also changes from CUTOFF to RUN.
"When fuel control switches are translated from CUTOFF to RUN during flight of the aircraft, each engine's full authority dual engine control (FADEC) will automatically control a relight and thrust recovery sequence of ignition and fuel introduction," the report stated. "The EGT (Exhaust Gas Temperature) was seen to be increasing for both engines, showing relight. Core deceleration ceased, reversed, and began to move towards recovery in engine 1. Engine 2 successfully relit but could not stop core speed deceleration and re-introduced fuel continuously to accelerate core speed and recovery," the report added. The EAFR recording cut off at 08:09:11 UTC (Coordinated Universal Time).
What are Boeing 787 Fuel Control Switches?
Boeing 787 fuel control switches control the fuel supply to individual engines. Used mainly for engine starting or shutdown on the ground, these switches have protective systems in place to stop movement by accident in flight. Pilots intentionally pull and slide the spring-loaded switches from 'RUN' to 'CUTOFF' or vice versa. Aviation safety analysts cited by Reuters emphasise that these switches have an essential function in the plane's operation. "No rational pilot would ever turn them off during flight, particularly during climb," opined John Nance, an American aviation safety consultant.
As per the initial crash report, flight data indicated that seconds after takeoff, both engines' fuel switches flipped from 'RUN' to 'CUTOFF' exactly one second apart from each other. Cockpit voice recordings caught one pilot asking the other if he had moved the switch, but neither accepted blame. Despite the fact that both switches reverted to 'RUN' seconds later, the engines had by then lost power. The plane crashed seconds later. At the site of the crash, investigators established that both switches were in the 'RUN' position, verifying the in-flight reversion. Experts in aviation explain to Reuters that accidental activation is extremely unlikely. "You can't just bump these switches; they are intentionally spring-loaded and gated to prevent inadvertent usage," said US-based aviation safety consultant John Cox. Adding to the mystery, that neither engine manufacturer General Electric nor aircraft manufacturer Boeing has made a formal safety alert or MOM since last month, India's civil aviation authority had gone through the black box information. According to experts, this indicates that a mechanical failure is not yet the main reason being probed.
When Are Boeing 787 Fuel Switches Turned Off or On?
Fuel shut-off switches or fuel pump shut-off systems are routine safety devices on aircraft as well as automobiles.In automobiles, analogous inertia switches shut off fuel in the event of an impact to avoid leaks and fires. On airplanes, the switches are pilot-actuated and employed only for engine restart or shutdown procedures, e.g., in an emergency or on the ground during maintenance. When transferred to 'CUTOFF', the switch immediately shuts down fuel flow, shutting off engine thrust and eliminating power to systems dependent upon the engines' generators, a potentially disastrous situation if executed during critical flight maneuvers such as takeoff or climb.
Engine Start: The most common application of fuel switches is engine startup and shutdown when the plane is on the ground. Before takeoff, pilots first switch the switches from 'CUTOFF' to 'RUN' so that fuel can supply the engines for firing. Upon landing and taxiing to the gate, pilots switch them back to 'CUTOFF' to shut down the engines safely.
In-Flight Emergency Situations: During flight, the fuel switches can be shifted to 'CUTOFF' only in exceptional emergencies. As an example, if there is a fire or catastrophic failure of an engine, then the fuel switch can be used by pilots to immediately cut off fuel supply to such an engine, cutting power to avoid more damage or fire propagation. Newer aircraft engines also have automatic fuel cutoff switches, but the manual switches act as a vital backup, allowing pilots to have control directly when necessary. Engine Relight Following Shutdown: When an engine is shut down during flight, either deliberately because of a failure or accidentally because of flameout, the pilots can try to restart it in-flight. To do so, they push the fuel switch rearward from 'CUTOFF' to 'RUN'. The engine control system of the aircraft then coordinates ignition and fuel supply to relight the engine safely, if all requirements are in place.
Protected Against Accidental Actuation: Due to their significance, these switches are mechanically protected against accidental actuation. A pilot will need to pull the switch up against a spring-loaded mechanism before moving it in the opposite direction. This guards against unintentional shut-off of an engine by bumps or vibrations, a vital protection particularly during takeoff, climb, or turbulence.
No In-Built Trigger in Day-to-Day Operations: While cars possess inertia fuel shut-off switches that switch off fuel automatically after accidents, an airliner's fuel switches are purely pilot-operated. They do not switch automatically due to turbulence, hard landings, or abrupt maneuvers.
On 17th December 2018, the Federal Aviation Administration (FAA) published a Special Airworthiness Information Bulletin (SAIB) on the possibility of disengagement of the fuel control switch locking feature. The SAIB came out following reports by operators of 737 aircraft that the fuel control switches had been installed with the locking feature inoperative. AAIB reported that the issue was not thought to be an unsafe condition requiring an airworthiness directive by the FAA. "The fuel control switch design, which includes the locking feature, is common on several Boeing airplane models, such as part number 4TL837-3D, which is installed in B787-8 aircraft VT-ANB." "According to Air India information, the proposed inspections were not performed since the SAIB was advisory and not obligatory," the report stated.
While families wait for answers, investigators are looking at whether switches were manipulated due to human error, a mechanical failure, or a potential system failure. The final report should propose increased cockpit protections if any design or procedural deficiencies are found. The Air India crash has reopened debate over Boeing 787 Dreamliner flight safety procedures and the necessity of fail-safes to avoid inadvertent fuel shut-off in mid-air.
