A B747-400 captain experienced multiple failures apparently related to electrical bus failure; elect...

Attributes
ACN	883563
Time
Date	201004
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B747-400
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Other Controlled
Component
Aircraft Component	Electrical Distribution Busbar
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 15000
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

Passing FL250 the crew heard a noise; and simultaneously lost the left radio; the captain's radio panel; and received numerous EICAS and status messages (about 20 of them); seemingly unrelated to each other. We elected to level off and trouble shoot. It seemed to be some sort of electrical bus failure; leading to multiple systems failure indications. Ultimately; we decided to return to departure airport. First officer flew and coordinated with ATC; captain consulted with dispatch and maintenance to determine what was wrong; and right; with the aircraft. No checklist really applied to the overall problem; although we did run several EICAS-driven checklists. Dispatcher declared emergency for flight; which we agreed with. Crew coordinated radar vectors to fully address the situation and landing considerations. We had flight control and flight operations run landing numbers for us to ensure we could return safely. Landed with anti-skid failure and brake limiter failure; captain landed otherwise uneventfully.

Original NASA ASRS Text

Title: A B747-400 Captain experienced multiple failures apparently related to electrical bus failure; elected to declare an emergency and returned to departure airport.

Narrative: Passing FL250 the crew heard a noise; and simultaneously lost the left radio; the Captain's radio panel; and received numerous EICAS and Status messages (about 20 of them); seemingly unrelated to each other. We elected to level off and trouble shoot. It seemed to be some sort of electrical bus failure; leading to multiple systems failure indications. Ultimately; we decided to return to departure airport. First Officer flew and coordinated with ATC; Captain consulted with Dispatch and Maintenance to determine what was wrong; and right; with the aircraft. No checklist really applied to the overall problem; although we did run several EICAS-driven checklists. Dispatcher declared emergency for flight; which we agreed with. Crew coordinated radar vectors to fully address the situation and landing considerations. We had Flight Control and Flight Operations run landing numbers for us to ensure we could return safely. Landed with anti-skid failure and brake limiter failure; Captain landed otherwise uneventfully.

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.

A B747-400 captain experienced multiple failures apparently related to electrical bus failure; elected to declare an emergency and returned to departure airport.