Narrative:

Following a normal takeoff on runway 36 at rkjk (kunsan airbase, korea), during climb out in VMC, night conditions, a very loud, sharp, 'bang' was heard in the cockpit at about 3000 ft MSL. The bang occurred immediately after the slats were retracted, and as the captain was calling for the after takeoff checklist. Captain was hand flying the aircraft, although night VMC prevailed, it was a dark night, with no visible horizon. Crew was in agreement that the bang was external to the aircraft, somewhere under the cockpit area. During this discussion a light, burning smell was discerned, but rapidly dissipated. All aircraft system were normal. The captain continued manually flying the aircraft to insure flight control integrity and the autoplt was subsequently engaged about 8000 ft MSL. With no abnormal aircraft system indications, I sent the international relief officer to the cabin to check for any abnormal noises and to discuss the situation with the in-flight service manager (ism) and to assure the flight attendant crew that everything was 'okay.' kunsan ATC asked if we required any assistance, but we declined as all system were operating normally. We were then handed off to the next ATC sector, which I believe was 'tokyo control.' the international relief officer returned from the cabin and advised that there was nothing abnormal in the cabin and that the flight attendants were informed that everything was normal in the cockpit. With all 3 crew members back in the cockpit we discussed the possibilities. We had ruled out a midair collision, a blown nose-gear tire, any aircraft system and now centered on a bird strike. We agreed that a large crane, hawk, etc, that struck the fuselage, somewhere near the cockpit or nose area, could have disintegrated with some of these parts being ingested into an air-conditioning pack inlet or an engine. We were continuing scrutiny of all engine parameters, but no abnormalities were observed, including the engine vibration monitors. We were in agreement that engine damage had not occurred. I made the decision to continue the flight to destination as we had absolutely no reason to do otherwise. Returning to kunsan air base or diverting to another suitable airport would have required a fuel dump of approximately 130000 pounds to achieve maximum certificated landing weight. The in-flight service manager then informed us that a passenger wanted to speak with the crew about something he saw on the #3 engine. I asked the international relief officer to investigate and he returned several mins later and explained there was a dent at the 12 O'clock position, of the engine inlet cowl ring and a long, red streak on the side of the #1 engine. I had previously told the 2 first officer's that concurrent with the loud bang, I had observed a bright flash from the peripheral vision of my left eye. My theory was that if a large bird had impacted the left landing light, which extends 90 degrees into the airstream when extended, this would explain the bright flash, as the glass would have shattered at this impact. We further discussed some of the carcass continuing past the #1 engine, which would explain the red (blood) streak and the rest going under the fuselage and impacting the #3 engine cowl, or perhaps there were 2 or more birds? I then established a phone patch with company maintenance control to advise them of the dent in the #3 cowl ring, probable bird(south) strike and marginal dispatch capability of the aircraft at anchorage. The rest of this flight was normal and without incident. During postflt we discovered the magnitude of the situation for the first time. We had apparently impacted a large flock of birds numbering 30-40, which had destroyed both landing lights and dented the #3 and #1 engine inlet cowl rings. Red 'hit' marks pocked the aircraft from the pack inlets back to the slats, where one carcass remained, as the slats trapped it at the O degree/retract position. The #1 engine cowl dent was not visible in-flight as it was on the outboard section. Based on the available information in-flight and complete lack of any aircraft system abnormalities, I believe we made the correct decision to continue to destination.

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Original NASA ASRS Text

Title: MULTIPLE BIRD STRIKES ON MD11 ARE ASSESSED AS NOT CAUSING ENOUGH DAMAGE TO REQUIRE A RETURN TO DEP STATION. CONSIDERABLE DAMAGE IS FOUND ON LNDG AFTER A PACIFIC XING.

Narrative: FOLLOWING A NORMAL TKOF ON RWY 36 AT RKJK (KUNSAN AIRBASE, KOREA), DURING CLBOUT IN VMC, NIGHT CONDITIONS, A VERY LOUD, SHARP, 'BANG' WAS HEARD IN THE COCKPIT AT ABOUT 3000 FT MSL. THE BANG OCCURRED IMMEDIATELY AFTER THE SLATS WERE RETRACTED, AND AS THE CAPT WAS CALLING FOR THE AFTER TKOF CHKLIST. CAPT WAS HAND FLYING THE ACFT, ALTHOUGH NIGHT VMC PREVAILED, IT WAS A DARK NIGHT, WITH NO VISIBLE HORIZON. CREW WAS IN AGREEMENT THAT THE BANG WAS EXTERNAL TO THE ACFT, SOMEWHERE UNDER THE COCKPIT AREA. DURING THIS DISCUSSION A LIGHT, BURNING SMELL WAS DISCERNED, BUT RAPIDLY DISSIPATED. ALL ACFT SYS WERE NORMAL. THE CAPT CONTINUED MANUALLY FLYING THE ACFT TO INSURE FLT CTL INTEGRITY AND THE AUTOPLT WAS SUBSEQUENTLY ENGAGED ABOUT 8000 FT MSL. WITH NO ABNORMAL ACFT SYS INDICATIONS, I SENT THE IRO TO THE CABIN TO CHK FOR ANY ABNORMAL NOISES AND TO DISCUSS THE SIT WITH THE INFLT SVC MGR (ISM) AND TO ASSURE THE FLT ATTENDANT CREW THAT EVERYTHING WAS 'OKAY.' KUNSAN ATC ASKED IF WE REQUIRED ANY ASSISTANCE, BUT WE DECLINED AS ALL SYS WERE OPERATING NORMALLY. WE WERE THEN HANDED OFF TO THE NEXT ATC SECTOR, WHICH I BELIEVE WAS 'TOKYO CTL.' THE IRO RETURNED FROM THE CABIN AND ADVISED THAT THERE WAS NOTHING ABNORMAL IN THE CABIN AND THAT THE FLT ATTENDANTS WERE INFORMED THAT EVERYTHING WAS NORMAL IN THE COCKPIT. WITH ALL 3 CREW MEMBERS BACK IN THE COCKPIT WE DISCUSSED THE POSSIBILITIES. WE HAD RULED OUT A MIDAIR COLLISION, A BLOWN NOSE-GEAR TIRE, ANY ACFT SYS AND NOW CTRED ON A BIRD STRIKE. WE AGREED THAT A LARGE CRANE, HAWK, ETC, THAT STRUCK THE FUSELAGE, SOMEWHERE NEAR THE COCKPIT OR NOSE AREA, COULD HAVE DISINTEGRATED WITH SOME OF THESE PARTS BEING INGESTED INTO AN AIR-CONDITIONING PACK INLET OR AN ENG. WE WERE CONTINUING SCRUTINY OF ALL ENG PARAMETERS, BUT NO ABNORMALITIES WERE OBSERVED, INCLUDING THE ENG VIBRATION MONITORS. WE WERE IN AGREEMENT THAT ENG DAMAGE HAD NOT OCCURRED. I MADE THE DECISION TO CONTINUE THE FLT TO DEST AS WE HAD ABSOLUTELY NO REASON TO DO OTHERWISE. RETURNING TO KUNSAN AIR BASE OR DIVERTING TO ANOTHER SUITABLE ARPT WOULD HAVE REQUIRED A FUEL DUMP OF APPROX 130000 LBS TO ACHIEVE MAX CERTIFICATED LNDG WT. THE INFLT SVC MGR THEN INFORMED US THAT A PAX WANTED TO SPEAK WITH THE CREW ABOUT SOMETHING HE SAW ON THE #3 ENG. I ASKED THE IRO TO INVESTIGATE AND HE RETURNED SEVERAL MINS LATER AND EXPLAINED THERE WAS A DENT AT THE 12 O'CLOCK POS, OF THE ENG INLET COWL RING AND A LONG, RED STREAK ON THE SIDE OF THE #1 ENG. I HAD PREVIOUSLY TOLD THE 2 FO'S THAT CONCURRENT WITH THE LOUD BANG, I HAD OBSERVED A BRIGHT FLASH FROM THE PERIPHERAL VISION OF MY L EYE. MY THEORY WAS THAT IF A LARGE BIRD HAD IMPACTED THE L LNDG LIGHT, WHICH EXTENDS 90 DEGS INTO THE AIRSTREAM WHEN EXTENDED, THIS WOULD EXPLAIN THE BRIGHT FLASH, AS THE GLASS WOULD HAVE SHATTERED AT THIS IMPACT. WE FURTHER DISCUSSED SOME OF THE CARCASS CONTINUING PAST THE #1 ENG, WHICH WOULD EXPLAIN THE RED (BLOOD) STREAK AND THE REST GOING UNDER THE FUSELAGE AND IMPACTING THE #3 ENG COWL, OR PERHAPS THERE WERE 2 OR MORE BIRDS? I THEN ESTABLISHED A PHONE PATCH WITH COMPANY MAINT CTL TO ADVISE THEM OF THE DENT IN THE #3 COWL RING, PROBABLE BIRD(S) STRIKE AND MARGINAL DISPATCH CAPABILITY OF THE ACFT AT ANCHORAGE. THE REST OF THIS FLT WAS NORMAL AND WITHOUT INCIDENT. DURING POSTFLT WE DISCOVERED THE MAGNITUDE OF THE SIT FOR THE FIRST TIME. WE HAD APPARENTLY IMPACTED A LARGE FLOCK OF BIRDS NUMBERING 30-40, WHICH HAD DESTROYED BOTH LNDG LIGHTS AND DENTED THE #3 AND #1 ENG INLET COWL RINGS. RED 'HIT' MARKS POCKED THE ACFT FROM THE PACK INLETS BACK TO THE SLATS, WHERE ONE CARCASS REMAINED, AS THE SLATS TRAPPED IT AT THE O DEG/RETRACT POS. THE #1 ENG COWL DENT WAS NOT VISIBLE INFLT AS IT WAS ON THE OUTBOARD SECTION. BASED ON THE AVAILABLE INFO INFLT AND COMPLETE LACK OF ANY ACFT SYS ABNORMALITIES, I BELIEVE WE MADE THE CORRECT DECISION TO CONTINUE TO DEST.

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.