A Southwest Airlines flight bound for Maryland returned to Pittsburgh International Airport after receiving a “maintenance indication,” officials say. A Southwest spokesperson says Flight 1399 landed safely after receiving the indication Monday morning. The crew followed safety procedures, and the plane landed without issue, the spokesperson says. The plane will be evaluated before returning to service. The flight was bound for Baltimore/Washington International Thurgood Marshall Airport. Southwest apologizes for any inconvenience to customers and will accommodate them to their final destination as soon as possible, the spokesperson says.