American Airlines Flight 438, an Airbus A321, had just departed from Dallas Ft. Worth en route to Seattle-Tacoma International Airport when flames were seen shooting out of the back of the engine, according to the FAA.
One passenger, who wishes to remain unnamed, shot a video from inside the plane showing emergency crews waiting on the tarmac. The plane made a hard landing, but all passengers and crew members are safe.
American Airlines spokesperson Ross Feinstein said the plane had a mechanical issue, more specifically the compressor within the engine.
The FAA echoed that explanation, saying an engine problem caused "compressor stalls." Compressor stalls are similar to an engine backfiring.
An Airbus A321 can perform safely with only a single working engine.
ABC News' Jonah Lustig contributed to this report.