B747-400 rejects takeoff due to failed bearings in no 2 engine.

Attributes
ACN	741758
Time
Date	200706
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : ord.airport
State Reference	IL
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B747-400
Operating Under FAR Part	Part 121
Flight Phase	climbout : initial
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 120 flight time total : 23000 flight time type : 200
ASRS Report	741758
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : rejected takeoff other
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Aircraft

Narrative:

We had just began our takeoff roll with the first officer flying. I had taken the xfer of the throttles and we were at approximately 50 KTS when we heard 3 loud bangs coming from the left side of the airplane. There was a slight turning of the airplane to the left and I aborted the takeoff. There were no observed abnormalities from the engine instruments and the aircraft taxied normally. No fire or smoke was observed from outside the aircraft and everything appeared normally from the tower and ground personnel checking the runway. We notified maintenance and returned to the gate. Maintenance met the aircraft as well as an O'hare runway inspector. I was informed that there was nothing on the runway from the ground personnel. The mechanics checked the computer and found a problem with the #2 engine. 1 mechanic came up to the cockpit with bearing parts from the #2 engine tailpipe. I was informed that the engine had approximately 20000 hours on it and had been written up as coming in from a previous flight with egt some 40 degrees C higher than the other engines. We deplaned the passenger and proceeded to another gate and airplane.

Original NASA ASRS Text

Title: B747-400 REJECTS TKOF DUE TO FAILED BEARINGS IN NO 2 ENGINE.

Narrative: WE HAD JUST BEGAN OUR TKOF ROLL WITH THE FO FLYING. I HAD TAKEN THE XFER OF THE THROTTLES AND WE WERE AT APPROX 50 KTS WHEN WE HEARD 3 LOUD BANGS COMING FROM THE L SIDE OF THE AIRPLANE. THERE WAS A SLIGHT TURNING OF THE AIRPLANE TO THE L AND I ABORTED THE TKOF. THERE WERE NO OBSERVED ABNORMALITIES FROM THE ENG INSTS AND THE ACFT TAXIED NORMALLY. NO FIRE OR SMOKE WAS OBSERVED FROM OUTSIDE THE ACFT AND EVERYTHING APPEARED NORMALLY FROM THE TWR AND GND PERSONNEL CHKING THE RWY. WE NOTIFIED MAINT AND RETURNED TO THE GATE. MAINT MET THE ACFT AS WELL AS AN O'HARE RWY INSPECTOR. I WAS INFORMED THAT THERE WAS NOTHING ON THE RWY FROM THE GND PERSONNEL. THE MECHS CHKED THE COMPUTER AND FOUND A PROB WITH THE #2 ENG. 1 MECH CAME UP TO THE COCKPIT WITH BEARING PARTS FROM THE #2 ENG TAILPIPE. I WAS INFORMED THAT THE ENG HAD APPROX 20000 HRS ON IT AND HAD BEEN WRITTEN UP AS COMING IN FROM A PREVIOUS FLT WITH EGT SOME 40 DEGS C HIGHER THAN THE OTHER ENGS. WE DEPLANED THE PAX AND PROCEEDED TO ANOTHER GATE AND AIRPLANE.

Data retrieved from NASA's ASRS site as of January 2009 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.