Narrative:

On takeoff roll; just prior to the V1 callout; the aircraft experienced what appeared to be a loss of an electrical bus (lost captain's HSI; CDU/FMC; and the upper EICAS screen). With no aircraft yawing or engine failure evident; the captain said 'continue' and I continued the takeoff. We soon discovered the autothrottle was inoperative; left pack off/inoperative lights; an equipment overheat light; a left IRU on dc light; left center fuel pump and right forward fuel pump off lights; an egpws fail light (along with associated EICAS messages compacted on the lower EICAS screen). We also had a left fuel override pump circuit breaker popped; and the brake pressure gauge indicating a loss of pressure. No electrical or hydraulic caution lights or EICAS messages were evident. I continued to fly the aircraft as the captain troubleshot the equipment overheat and pressurization issues. We leveled off at 10;000 ft after informing ATC that we would need to stay in the local area until we sorted out our multiple system problems. We proceeded to fly a large box pattern with a long final to runway xx. The captain briefed the flight attendants (cabin advisory) and passengers. As we discussed the need of declaring an emergency with ATC; dispatch sent us an ACARS message saying they had done it for us. We declared an emergency with ATC over the radio and set up for an approach to runway xx. Unsure of what other systems might be compromised; we elected to slow at altitude and lower the flaps. After selecting flaps post #1; the flap gauge showed the flaps as only partially out and slightly split. We asked the flight attendants to verify the position of the flaps and slats and again continued with the approach. The flap indication continued to lag our selected flaps setting as we lowered to flap position 30 degrees. On final approach; the left aft electric fuel pump and right engine electric hydraulic pump off lights illuminated. We transferred controls at the FAF and the captain flew the aircraft to touchdown with emergency equipment standing by. On landing; the thrust reversers wouldn't deploy past the idle detent.

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Original NASA ASRS Text

Title: B757 flight crew encountered multiple system malfunctions shortly after takeoff. Believed anomalies to have been the result of a failed electrical bus.

Narrative: On takeoff roll; just prior to the V1 callout; the aircraft experienced what appeared to be a loss of an electrical bus (lost Captain's HSI; CDU/FMC; and the upper EICAS screen). With no aircraft yawing or engine failure evident; the Captain said 'continue' and I continued the takeoff. We soon discovered the autothrottle was inoperative; left pack off/inoperative lights; an equipment overheat light; a left IRU on DC light; left center fuel pump and right forward fuel pump off lights; an EGPWS fail light (along with associated EICAS messages compacted on the lower EICAS screen). We also had a left fuel override pump CB popped; and the brake pressure gauge indicating a loss of pressure. No electrical or hydraulic caution lights or EICAS messages were evident. I continued to fly the aircraft as the Captain troubleshot the equipment overheat and pressurization issues. We leveled off at 10;000 FT after informing ATC that we would need to stay in the local area until we sorted out our multiple system problems. We proceeded to fly a large box pattern with a long final to Runway XX. The Captain briefed the Flight Attendants (cabin advisory) and passengers. As we discussed the need of declaring an emergency with ATC; Dispatch sent us an ACARS message saying they had done it for us. We declared an emergency with ATC over the radio and set up for an approach to Runway XX. Unsure of what other systems might be compromised; we elected to slow at altitude and lower the flaps. After selecting flaps post #1; the flap gauge showed the flaps as only partially out and slightly split. We asked the Flight Attendants to verify the position of the flaps and slats and again continued with the approach. The flap indication continued to lag our selected flaps setting as we lowered to flap position 30 degrees. On final approach; the left aft electric fuel pump and right engine electric hydraulic pump off lights illuminated. We transferred controls at the FAF and the Captain flew the aircraft to touchdown with emergency equipment standing by. On landing; the thrust reversers wouldn't deploy past the idle detent.

Data retrieved from NASA's ASRS site as of April 2012 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.