The incident is just the latest maintenance problem for United flights, with at least eight cropping up in the past two weeks. No injuries have been reported.
A United flight headed from San Francisco to Japan had to return to the gate from the runway because of mechanical issues, delaying the fight by five hours and making it at least the eighth flight with maintenance issues for the airline in the past couple weeks.
As United flight 35 taxied to the runway on Monday afternoon, it received an indication of an engine start issue. The pilot announced they were experiencing engine problems and the plane returned to the gate, according to a statement sent to USA TODAY from United Airlines.
When USA TODAY asked what triggered the indication, United said it did not have any information to share past its statement.
The plane, a Boeing 777, departed for Osaka at 4:56 p.m., almost five hours past the time it was supposed to take off.
String of incidents "sharpen our focus."
The incident occurred the same day United CEO Scott Kirby sent customers a letter acknowledging recent issues the airline faced in the last few weeks.
"Our airline has experienced a number of incidents that are reminders of the importance of safety," wrote Kirby. "While they are all unrelated, I want you to know that these incidents have our attention and have sharpened our focus."
At least eight incidents have happened on flights operated by United in the past two weeks, all taking off from or headed to airports in the U.S. and five involving planes made by Boeing, according to the New York Times. The incidents have ranged from a tire being lost shortly after takeoff and a fire started by plastic wrap, though none have caused injuries.
Kirby's letter says that his team is reviewing details from each case to understand what is happening and using the information they find to "inform our safety training and procedures across all employee groups."
The letter states that it will be in addition to changes that were already planned, like...
Adding an extra day of in-person training for all pilots starting in May
Centralize training curriculum for newly hired maintenance technicians
Article and image originally appeared on USA Today