A Southwest Airlines flight returned to Mitchell International Airport just 24 minutes after it took off early Tuesday morning.
The pilot reported a problem with one of the engines on the Boeing 737.
A passenger reported hearing two pops and seeing something that looked like a spark or flame from the right-wing.
The plane landed safely.
The flight to Baltimore originally took off at 6:00 a.m.
The 138 passengers were loaded on another plane and it departed at about 9:00 a.m.
Mechanics were inspecting the original plane at the gate after the passengers got off.
