Narrative:

The flight was in a twin engine be-76 leaving addison for local IFR training at night. Aircraft performance through takeoff and climb was normal. As the takeoff progressed through about 200 ft AGL, I happened to glance out my left window at the left engine. I was completely surprised to see the bottom of the engine cowling wreathed in a blue flame. I notified tower that we had a possible engine fire and that we were returning to land. Tower asked if we needed the equipment, I declined as at this point, power had been reduced and most of the flame had dissipated. An uneventful landing followed. Post-flight investigation showed no signs of fire. Upon consulting several other pilots and an a&P, it was determined that this was in fact normal behavior for the aircraft. Under certain atmospheric and engine conditions, the engines can produce quite a bit of flame. However, nowhere in the pilot operating handbook or in my training, or in my study, was I ever told to expect flame from a 180 hp engine. In my case, the result was 2 mins of terror and a little embarrassment. However, had the WX been worse, or had I elected to secure the engine, the outcome might not have been so happy. I consider myself to be a competent pilot. I had flown the aircraft many times at night, but had never seen this phenomena, which turns out to be quite common. This whole incident could have been avoided if someone, be it beechcraft, a CFI, or an FAA AC on flying twins had bothered to tell me to expect this common, rather unnerving phenomena.

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Original NASA ASRS Text

Title: PLT INST TRNEE RETURNED TO LAND AFTER TKOF DUE TO WHAT APPEARED TO BE AN ENG FIRE DURING THE START OF A NIGHT INST TRAINING FLT.

Narrative: THE FLT WAS IN A TWIN ENG BE-76 LEAVING ADDISON FOR LCL IFR TRAINING AT NIGHT. ACFT PERFORMANCE THROUGH TKOF AND CLB WAS NORMAL. AS THE TKOF PROGRESSED THROUGH ABOUT 200 FT AGL, I HAPPENED TO GLANCE OUT MY L WINDOW AT THE L ENG. I WAS COMPLETELY SURPRISED TO SEE THE BOTTOM OF THE ENG COWLING WREATHED IN A BLUE FLAME. I NOTIFIED TWR THAT WE HAD A POSSIBLE ENG FIRE AND THAT WE WERE RETURNING TO LAND. TWR ASKED IF WE NEEDED THE EQUIP, I DECLINED AS AT THIS POINT, PWR HAD BEEN REDUCED AND MOST OF THE FLAME HAD DISSIPATED. AN UNEVENTFUL LNDG FOLLOWED. POST-FLT INVESTIGATION SHOWED NO SIGNS OF FIRE. UPON CONSULTING SEVERAL OTHER PLTS AND AN A&P, IT WAS DETERMINED THAT THIS WAS IN FACT NORMAL BEHAVIOR FOR THE ACFT. UNDER CERTAIN ATMOSPHERIC AND ENG CONDITIONS, THE ENGS CAN PRODUCE QUITE A BIT OF FLAME. HOWEVER, NOWHERE IN THE PLT OPERATING HANDBOOK OR IN MY TRAINING, OR IN MY STUDY, WAS I EVER TOLD TO EXPECT FLAME FROM A 180 HP ENG. IN MY CASE, THE RESULT WAS 2 MINS OF TERROR AND A LITTLE EMBARRASSMENT. HOWEVER, HAD THE WX BEEN WORSE, OR HAD I ELECTED TO SECURE THE ENG, THE OUTCOME MIGHT NOT HAVE BEEN SO HAPPY. I CONSIDER MYSELF TO BE A COMPETENT PLT. I HAD FLOWN THE ACFT MANY TIMES AT NIGHT, BUT HAD NEVER SEEN THIS PHENOMENA, WHICH TURNS OUT TO BE QUITE COMMON. THIS WHOLE INCIDENT COULD HAVE BEEN AVOIDED IF SOMEONE, BE IT BEECHCRAFT, A CFI, OR AN FAA AC ON FLYING TWINS HAD BOTHERED TO TELL ME TO EXPECT THIS COMMON, RATHER UNNERVING PHENOMENA.

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.