B767 engine spool-down during climb while fuel xfeed operation was in progress.

Attributes
ACN	503579
Time
Date	200105
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : ogg.vortac
State Reference	HI
Altitude	msl single value : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zhn.artcc tower : lax.tower
Operator	common carrier : air carrier
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : pacific enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time total : 3200 flight time type : 632
ASRS Report	503579
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical non adherence : company policies non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	flight crew : landed as precaution flight crew : diverted to another airport flight crew : overcame equipment problem flight crew : became reoriented
Consequence	faa : reviewed incident with flight crew faa : investigated other other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Aircraft

Narrative:

Shortly after takeoff, passing through FL270, the captain asked me to balance the wing tanks, as we had about a 700 pound split. Turned off the right main pumps as I initially perceived this to be the low side. Several seconds later, I realized that the left side was low and I turned the right side back on and turned the left side off. At no time did I open the xfeed. Almost immediately captain reported a loss of thrust on the right engine followed immediately by 'we have lost both engines.' I immediately turned the left main fuel pumps on and started the qrc for loss of both engines. Before finishing the qrc, the captain reported that he had both engines back. I declared an emergency upon discussion with the captain. We decided on ZZZ as a divert due to its proximity and long runway length. We began a slow descent while working through the qrc and irregular eec items. We returned the eec's to their primary mode and all EICAS indications returned to normal. Upon receiving clearance, we landed in ZZZ. We decided on a heavy landing because we did not know the exact cause of the engine malfunction. We also believed that it could happen again without warning. I feel that this incident was caused by fuel starvation to the engines while the pumps were off. Callback conversation with reporter revealed the following information: reporter said the engines rolled back to approximately 40% N2 and that both generators dropped off line. The total time, determined from the flight recorder from fuel boost pump switching being turned off to engine rollback, was approximately 14 seconds. The aircraft was test flown and the condition was repeated on the test flight. It was found that the engines would suction feed, if it was begun around 10000 ft, right on up to the service ceiling of the aircraft. If, however, it was begun at higher altitudes engine spool-down occurred. The aircraft was recently fueled and it is believed that aeration and fuel cavitation were contributing factors. The MEL has since been changed to require all tank pumps be operable for dispatch. The reporter is concerned that his training and aircraft manuals indicate that the engine fuel pumps will suction feed without fuel tank boost pumps.

Original NASA ASRS Text

Title: B767 ENG SPOOL-DOWN DURING CLB WHILE FUEL XFEED OP WAS IN PROGRESS.

Narrative: SHORTLY AFTER TKOF, PASSING THROUGH FL270, THE CAPT ASKED ME TO BAL THE WING TANKS, AS WE HAD ABOUT A 700 LB SPLIT. TURNED OFF THE R MAIN PUMPS AS I INITIALLY PERCEIVED THIS TO BE THE LOW SIDE. SEVERAL SECONDS LATER, I REALIZED THAT THE L SIDE WAS LOW AND I TURNED THE R SIDE BACK ON AND TURNED THE L SIDE OFF. AT NO TIME DID I OPEN THE XFEED. ALMOST IMMEDIATELY CAPT RPTED A LOSS OF THRUST ON THE R ENG FOLLOWED IMMEDIATELY BY 'WE HAVE LOST BOTH ENGS.' I IMMEDIATELY TURNED THE L MAIN FUEL PUMPS ON AND STARTED THE QRC FOR LOSS OF BOTH ENGS. BEFORE FINISHING THE QRC, THE CAPT RPTED THAT HE HAD BOTH ENGS BACK. I DECLARED AN EMER UPON DISCUSSION WITH THE CAPT. WE DECIDED ON ZZZ AS A DIVERT DUE TO ITS PROX AND LONG RWY LENGTH. WE BEGAN A SLOW DSCNT WHILE WORKING THROUGH THE QRC AND IRREGULAR EEC ITEMS. WE RETURNED THE EEC'S TO THEIR PRIMARY MODE AND ALL EICAS INDICATIONS RETURNED TO NORMAL. UPON RECEIVING CLRNC, WE LANDED IN ZZZ. WE DECIDED ON A HVY LNDG BECAUSE WE DID NOT KNOW THE EXACT CAUSE OF THE ENG MALFUNCTION. WE ALSO BELIEVED THAT IT COULD HAPPEN AGAIN WITHOUT WARNING. I FEEL THAT THIS INCIDENT WAS CAUSED BY FUEL STARVATION TO THE ENGS WHILE THE PUMPS WERE OFF. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR SAID THE ENGS ROLLED BACK TO APPROX 40% N2 AND THAT BOTH GENERATORS DROPPED OFF LINE. THE TOTAL TIME, DETERMINED FROM THE FLT RECORDER FROM FUEL BOOST PUMP SWITCHING BEING TURNED OFF TO ENG ROLLBACK, WAS APPROX 14 SECONDS. THE ACFT WAS TEST FLOWN AND THE CONDITION WAS REPEATED ON THE TEST FLT. IT WAS FOUND THAT THE ENGS WOULD SUCTION FEED, IF IT WAS BEGUN AROUND 10000 FT, RIGHT ON UP TO THE SVC CEILING OF THE ACFT. IF, HOWEVER, IT WAS BEGUN AT HIGHER ALTS ENG SPOOL-DOWN OCCURRED. THE ACFT WAS RECENTLY FUELED AND IT IS BELIEVED THAT AERATION AND FUEL CAVITATION WERE CONTRIBUTING FACTORS. THE MEL HAS SINCE BEEN CHANGED TO REQUIRE ALL TANK PUMPS BE OPERABLE FOR DISPATCH. THE RPTR IS CONCERNED THAT HIS TRAINING AND ACFT MANUALS INDICATE THAT THE ENG FUEL PUMPS WILL SUCTION FEED WITHOUT FUEL TANK BOOST PUMPS.

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.