A United Airlines flight from Charlotte, North Carolina, to Houston had to divert to Atlanta Wednesday because of a mechanical issue.

United did not go into detail on the nature of the issue. However, the Federal Aviation Administration, which is investigating the incident, said, “United Airlines Flight 575 landed safely at Hartsfield-Jackson Atlanta International Airport around 8 a.m. local time on Wednesday, Jan. 31, after the crew reported a possible engine issue.”

According to the airline, there were 131 passengers and six crew members on board the Boeing 737-800.