An All Nippon Airways (ANA) Boeing 777 was forced to divert to Chicago O’Hare Airport, the US, after suffering engine vibrations during the flight to Tokyo-Narita International Airport, Japan.
On January 20, 2021, the All Nippon Airways Boeing 777-300ER, registered as JA794A, was en route from Chicago O’Hare Airport (ORD) to Tokyo-Narita International Airport (NRT) when the flight crew noticed unusual vibrations in the left engine of the aircraft. The incident occurred shortly after take-off when the jet was climbing out of runway 28R at the ODR airport and received a clearance to climb to 15,000 feet.
According to the initial incident report, the aircraft stopped climbing after reaching 12,000 feet and the pilots declared an emergency by squawking a 7700 distress signal. The flight crew reported the Air Traffic Control (ATC) having experienced vibrations on the left-hand engine and were cleared to enter a hold.
About 20 minutes later, while holding at a flight altitude of 6,000 feet, the flight crew reported being able to stabilize the parameters of the engine and kept the engine at idle power. After receiving clearance to divert to Chicago, in order to reduce the landing weight, the crew decided to dump fuel and safely landed on runway 22L at ODR airport about 95 minutes after departure.
Fortunately, no injuries were reported. The All Nippon Airways Boeing 777-300ER rolled out without further incident.