First report on Boeing crash: fuel supply to engines was cut off after takeoff

Air India's Boeing 787 Dreamliner crashed shortly after takeoff on June 12 due to a fuel cutoff in both engines, according to a preliminary report by the Air Accident Investigation Bureau of India (AAIB). The crew failed to regain thrust in time to avoid tragedy: the aircraft crashed into an urban development, killing 260 people. Investigators found no significant malfunction of the airplane or its engines, but described a known feature of another Boeing model that could theoretically have led to a fuel cutoff.

The document, published a month after the crash of the Air India plane, describes the events before the plane went down in a densely populated area of the Indian city of Ahmedabad. According to the chronology outlined in the report, almost immediately after takeoff, both fuel supply switches to the engines were switched to the cutoff (i.e., "off") position from the run (i.e., "running") position. As the fuel supply to the engines was cut off, they lost thrust and the airplane began to descend.

The reason for switching the toggle switch has not yet been established. The transcript of cockpit conversations records an episode when one of the pilots asked the other pilot why he had turned off the fuel supply, to which the other replied that he had not done so. The pilots then restored the fuel supply, but the engines did not have time to gain thrust before the collision. Only about 30 seconds elapsed between takeoff and the crash.

During takeoff, the co-pilot controlled the airplane while the captain monitored the flight. The report does not specify which pilot asked the question and which pilot answered it. The flight's crew commander had more than 10,000 hours of flying time on wide-body aircraft, Air India said. Второй пилот имел опыт более 3400 часов полетов, пишет The Wall Street Journal.

The investigation is ongoing and it is not yet clear whether the fuel cutoff to the engines was caused by crew error, a technical malfunction or another factor, stated Bloomberg. A final report on the crash is expected to be released in a few months.  

Investigators said they found no evidence to suggest the Boeing or the GE engines aboard it malfunctioned.

"No recommendations are being made to the operators or manufacturers of Boeing 787-8 aircraft and/or GE GE GEnx-1B engines during the current phase of the investigation, indicating that there are no identified serious defects in the airplane's design or its engines," the report said.

The problem with the fuel switch likely means the crash is not related to a design flaw, wrote two days before the report was released, Vertical Research Partners analyst Rob Stallard wrote in a note cited by Barron's.

The AAIB report also indicates that the FAA issued an airworthiness bulletin in 2018 regarding a smaller model, the Boeing 737. The document said the fuel switches could inadvertently shift from run to cutoff position without triggering the safety lock. The Air India plane was not inspected for this defect because such an inspection was never required, investigators said.

The report is based on data from the flight voice recorder (CVR), digital flight data recorder (FDR) and information collected at the scene of the tragedy. AAIB specialists said they intend to examine additional evidence, records and information;

The crashed aircraft made its maiden flight in 2013 and was handed over to Air India in early 2014, Flightradar24 reported.

The Boeing 787 has flown 41,700 hours and made about 7,800 flights. In 2023, it underwent a comprehensive C-check type inspection, which is performed every 20-24 months. The engines underwent an overhaul earlier this year in accordance with standard operating procedures, reports Barron's.

According to data Bloomberg, the plane was produced shortly after the launch of the 787 program, when Boeing was facing the fallout from a decision to outsource much of its design and engineering work to third-party contractors in an effort to cut costs. As part of the Dreamliner program, the jetliner had a factory number of 26 - meaning it was among the first 60 planes that were subsequently heavily modified after leaving Boeing's factory.

Assembly of the plane for Air India began in August 2010, according to All Things 787, a blog that tracked Boeing's production at the time. The plane was not delivered to the airline until more than three years later, a typical timeframe for early Dreamliners that required extensive modernization, Bloomberg notes.

The Dreamliner remains extremely popular with airlines, but there were problems with it early in its operation. Less than two years after its launch, Boeing was forced to suspend operations of its entire Dreamliner fleet to test its lithium-based batteries - there was a risk of them overheating and catching fire, reminds Bloomberg.

This article was AI-translated and verified by a human editor