The ‘Boom’ Before The Fall: Boeing 787’s Electrical System Under Scanner After Air India Crash

Last Updated:June 16, 2025, 12:36 IST

A mysterious "boom", a rapid descent, and questions swirling around Boeing 787’s electric systems — could a critical design flaw have led to the deadly Air India AI 171 crash?

DGCA's initial safety directives indicate that there was a problem in the aircraft's electrical system. (PTI/File)

Days after the tragic crash of Air India flight AI 171, questions continue to mount over what caused the fatal accident that left only one survivor. While some experts are examining the possibility of failure in one or both engines, several senior pilots now suspect an electrical system malfunction, adding a new layer to the ongoing investigation.

The Boeing 787 is a “more-electric aircraft", relying on electrical systems rather than traditional hydraulic and pneumatic ones to reduce weight and improve fuel efficiency. However, this very design feature is now under scrutiny, with some experts suggesting it may have contributed to the failure that led to the crash.

The VFSG (Variable Frequency Starter Generator) system, a critical subsystem serving as both an engine starter and generator, is under scrutiny. Experts suspect that the “boom" sound heard during the flight may be linked to a malfunction in the electrical system, potentially causing an excessive or complete cut-off in electric supply to the engines. In such a scenario, even the pilots would have little to no control over the situation.

The sole survivor reported hearing a “boom", suggesting a possible partial or complete engine failure. However, modern aircraft like the Boeing 787 should not crash due to the failure of just one engine, prompting further investigation into whether both engines failed.

How Many Twin-Engine Aircraft Have Crashed?

Delving into the history of dual-engine flight crashes, only seven such instances have been recorded, mostly due to bird strikes, incorrect engine shutdowns, or fuel issues. The possibility of a bird strike has been ruled out in this case. Questions remain about whether the crash resulted from an incorrect engine shutdown or a fuel problem.

What Caused The Mysterious ‘Boom’ Sound

A senior B787 pilot said, “The boom sound indicates an engine shutdown, but why did the plane descend so rapidly? Could it be that the pilots mistakenly shut down the right engine?"

Many pilots believe that during the first 400 feet of takeoff, the crew focuses mainly on assessing the situation. Since the fuel cutoff process takes time, the accident likely occurred before any such action was possible. Some pilots have also suggested that the crew may have made an error due to the ‘startle effect’, such as retracting the flaps instead of the landing gear. However, if even one engine was functioning, the aircraft should have been capable of returning safely.

What Could Have Gone Wrong

Experts are also examining the VFSG (Variable Frequency Starter Generator) system, which not only starts the engine but also supplies the main electrical power during flight. If the VFSG fails, the Electronic Engine Control (EEC), also known as the ‘throttle computer’, may shut down, causing the engine to remain in ‘idle’ mode, preventing the pilots from increasing thrust, even if required.

The APU (Auxiliary Power Unit) also helps in such situations, but it takes 90 seconds to reach full RPM (Revolutions Per Minute). According to experts, the entire AI 171 crash unfolded in just 32 seconds, making it impossible to rely on the APU.

DGCA’s initial safety directives also indicate that there was a problem in the aircraft’s electrical system, which affected engine responsiveness.

Some experts are also talking about the possible deployment of the RAT (Ram Air Turbine), a small turbine that provides power in case of emergency. However, RAT only supports basic controls and does not enable landing. Pictures of a black patch have also surfaced, which is being linked to the deployment of the RAT.

Air safety expert Captain Amit Singh blamed overloading for the tragedy. He said that if excess cargo was loaded onto the plane, a long takeoff and a crash after an engine failure would have been inevitable.

A senior B777 pilot put forward another theory — the pilots may have mistakenly entered zero fuel weight, causing the computer to make incorrect thrust calculations. As a result, the takeoff thrust was insufficient, and the plane failed to climb properly.

Location :

First Published:

News india The ‘Boom’ Before The Fall: Boeing 787’s Electrical System Under Scanner After Air India Crash