A cut in the fuel supply to the engines caused last month’s Air India crash that killed 260 people, a preliminary report has found.
The London-bound plane had barely left the runway at Ahmedabad airport when it hurtled back to earth. Everyone on board was killed, except for one passenger.
According to the report by India’s Aircraft Accident Investigation Bureau, obtained by CNN, the fuel control switches in the cockpit of the Boeing 787 Dreamliner had been flipped, starving the engines of fuel.
Investigators were able to get data out of the plane’s “black box” recorders, including 49 hours of flight data and two hours of cockpit audio, including from the crash.
The aircraft had reached an airspeed of 180 knots when both engines’ fuel cutoff switches were “transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec,” according to the report.
“In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so,” the report reads.
Shortly after, the switches were reversed back to where they should have been, and the engines were in the process of powering back up when the crash happened.
On the 787, the fuel cutoff switches are between the two pilots’ seats, immediately behind the plane’s throttle levers. They are protected on the sides by a metal bar and have a locking mechanism designed to prevent accidental cutoff.
Airport footage shows the Ram Air Turbine, an emergency power source on an aircraft, deployed during the plane’s initial climb after takeoff, the report said. The plane started to lose altitude before crossing the airport perimeter wall.
“When fuel control switches are moved from CUTOFF to RUN while the aircraft is inflight, each engines full authority dual engine control automatically manages a relight and thrust recovery sequence of ignition and fuel introduction,” the report states.
Seconds after the engines attempted to relight, one pilot called out, “MAYDAY MAYDAY MAYDAY.” The controller called out for the plane’s callsign, but didn’t get a response and watched the plane crash in the distance.
The fuel switches were “designed to be intentionally moved,” according to CNN safety analyst David Soucie, who said cases in which all fuel switches were turned off accidentally are “extremely rare.”
“Throughout the years, those switches have been improved to make sure that they cannot be accidentally moved and that they’re not automatic. They don’t move themselves in any manner,” Soucie said on Friday.
The captain of the flight was a 56-year-old who had flown more than 15,000 hours in his career. The first officer was a 32-year old man with over 3,400 flying hours.
Investigators also noted settings on equipment found in the wreckage was normal for takeoff. The plane’s fuel was tested and found to be of satisfactory quality, and no significant bird activity is observed in the vicinity of the flight path, according to the report.
The takeoff weight for the plane was found to be within allowable limits, and there were no “Dangerous Goods” on the aircraft. Investigators found the flaps on the wings of the plane were set in the 5-degree position, which is correct for takeoff, and the landing gear lever was in the down position.
The left engine was installed on the plane on March 26 and the right was installed on May 1, the report said.
Air India flight 171 took off from Ahmedabad’s Sardar Vallabhbhai Patel International Airport in India’s western state of Gujarat on June 12. The Boeing 787-8 Dreamliner was headed to London Gatwick, and scheduled to land at 6:25 p.m. local time.
Air India had said 242 passengers and crew members were on board. That included 169 Indian nationals, 53 Britons, seven Portuguese and one Canadian.
In addition to those on board, a number of people on the ground were killed when the plane crashed into the BJ Medical College and Hospital hostel.
The crash resulted in 260 fatalities total, according to the report. A number of the dead on the ground resulted from the plane hitting the hostel.
Air India acknowledged that it received the report and said it will continue cooperating with authorities in the investigation.
“Air India stands in solidarity with the families and those affected by the AI171 accident,” the airline posted to X on Saturday (local time). “We continue to mourn the loss and are fully committed to providing support during this difficult time.”
Source: CNN
--Agencies
