Narrative:

The captain and myself where departing. At around 600 ft afe there was a very loud bang and the aircraft had a significant yawing moment to the right. We both looked at the engine instruments and did not see anything indicating an engine malfunction. I kept flying the airplane and the captain started to analyze the situation. My thoughts were a compressor stall or a bird strike which I shared with the captain. About a minute later the flight attendant called up to the captain and said that several passengers had seen a very large flame come out the back of the number 2 engine. All indications on every system where showing no issues. The plane was handling fine. The captain had decided due to the very loud bang and the yawing moment plus the passenger assessment that we would return to the departure airport and not fly in the airplane. The captain handled all duties as the non flying pilot and I flew the airplane. The captain called operations and advised them of our air return and that maintenance should be expecting a possible bird strike and a definite overweight landing. ATC handled us back to [departure airport] with a successful landing. No emergency was ever declared because the captain and I did not think it was necessary. The captain handled the entire situation extremely professional and it was a very excellent example of CRM and doing what we are trained to do. After returning to the gate and maintenance inspecting the airplane it was determined that it was not a bird strike but a very likely compressor stall.

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Original NASA ASRS Text

Title: A B-737 crew reported a compressor stall at 600 FT after takeoff so they returned to the departure airport where Maintenance determined the cause was an engine malfunction and not a bird strike.

Narrative: The Captain and myself where departing. At around 600 FT AFE there was a very loud bang and the aircraft had a significant yawing moment to the right. We both looked at the engine instruments and did not see anything indicating an engine malfunction. I kept flying the airplane and the Captain started to analyze the situation. My thoughts were a compressor stall or a bird strike which I shared with the Captain. About a minute later the Flight Attendant called up to the Captain and said that several passengers had seen a very large flame come out the back of the number 2 engine. All indications on every system where showing no issues. The plane was handling fine. The Captain had decided due to the very loud bang and the yawing moment plus the passenger assessment that we would return to the departure airport and not fly in the airplane. The Captain handled all duties as the non flying pilot and I flew the airplane. The Captain called Operations and advised them of our air return and that Maintenance should be expecting a possible bird strike and a definite overweight landing. ATC handled us back to [departure airport] with a successful landing. No emergency was ever declared because the Captain and I did not think it was necessary. The Captain handled the entire situation extremely professional and it was a very excellent example of CRM and doing what we are trained to do. After returning to the gate and Maintenance inspecting the airplane it was determined that it was not a bird strike but a very likely Compressor Stall.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.