Narrative:

During climb out from bwi at approximately 10000 ft, a flight attendant reported that a passenger said he saw sparks from the left engine. Our engine instruments were normal, so we asked the flight attendant to have a look at the engine and report what he sees. The flight attendant called back a few mins later and said yes, he sees intermittent flame coming from the left engine. Our indications were still normal. We got a hold of dispatch and had requested a patch to maintenance. A few mins later, at about FL190, 2 loud bangs came from the left engine which appeared to be compressor stalls.

Related reports:

Google
 

Original NASA ASRS Text

Title: B767 PAX NOTICED FLAMES COMING FROM THE L ENG DURING CLB AND, SUBSEQUENTLY IN THE CLB, THE FLC HEARD LOUD BANGS FROM THE ENG WHICH SOUNDED LIKE COMPRESSOR STALLS.

Narrative: DURING CLBOUT FROM BWI AT APPROX 10000 FT, A FLT ATTENDANT RPTED THAT A PAX SAID HE SAW SPARKS FROM THE L ENG. OUR ENG INSTS WERE NORMAL, SO WE ASKED THE FLT ATTENDANT TO HAVE A LOOK AT THE ENG AND RPT WHAT HE SEES. THE FLT ATTENDANT CALLED BACK A FEW MINS LATER AND SAID YES, HE SEES INTERMITTENT FLAME COMING FROM THE L ENG. OUR INDICATIONS WERE STILL NORMAL. WE GOT A HOLD OF DISPATCH AND HAD REQUESTED A PATCH TO MAINT. A FEW MINS LATER, AT ABOUT FL190, 2 LOUD BANGS CAME FROM THE L ENG WHICH APPEARED TO BE COMPRESSOR STALLS.

Data retrieved from NASA's ASRS site as of July 2007 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.