Primary electrical supply problem in a night operation.

Attributes
ACN	266338
Time
Date	199403
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : clt
State Reference	NC
Altitude	msl bound lower : 10000 msl bound upper : 33000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zjx tower : dca
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 180 flight time total : 19000 flight time type : 10000
ASRS Report	266338
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : exited adverse environment flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

At cruise FL330 en route from orlando, fl, to islip, ny, we lost all cockpit lighting for approximately 3-5 seconds. Followed by transfer to standby power on captain's instruments, first officer's lights and instruments continued to receive normal power, giving us conflicting information. As to nature of loss. Electrical instruments indicating normal readings. During search for popped circuit breaker, lost cabin pressure control. Initiated emergency descent procedures. Transponder would not respond to attempts to set 7700. Lost communication to ZJX. A mitsubishi aircraft relayed our distress call and provided new center frequency. Successful contact on new frequency. Requested immediate descent clearance to 10000 ft MSL, which was granted. Uneventful precautionary landing made at charlotte douglas airport with no injuries or aircraft damage. Maintenance inspections subsequently revealed internal failure of 'a' phase in #1 generator and the failure of a power module behind the circuit breaker panel. This type of failure has no established emergency procedure as the indications were contradicting each other. Our training continues to include 'vanilla type' malfunctions but reality is that when failures occur they tend to be compounded by other failures, both human and mechanical which frustrate the crew's attempt to solve the problem.

Original NASA ASRS Text

Title: PRIMARY ELECTRICAL SUPPLY PROB IN A NIGHT OP.

Narrative: AT CRUISE FL330 ENRTE FROM ORLANDO, FL, TO ISLIP, NY, WE LOST ALL COCKPIT LIGHTING FOR APPROX 3-5 SECONDS. FOLLOWED BY TRANSFER TO STANDBY PWR ON CAPT'S INSTS, FO'S LIGHTS AND INSTS CONTINUED TO RECEIVE NORMAL PWR, GIVING US CONFLICTING INFO. AS TO NATURE OF LOSS. ELECTRICAL INSTS INDICATING NORMAL READINGS. DURING SEARCH FOR POPPED CIRCUIT BREAKER, LOST CABIN PRESSURE CTL. INITIATED EMER DSCNT PROCS. XPONDER WOULD NOT RESPOND TO ATTEMPTS TO SET 7700. LOST COM TO ZJX. A MITSUBISHI ACFT RELAYED OUR DISTRESS CALL AND PROVIDED NEW CTR FREQ. SUCCESSFUL CONTACT ON NEW FREQ. REQUESTED IMMEDIATE DSCNT CLRNC TO 10000 FT MSL, WHICH WAS GRANTED. UNEVENTFUL PRECAUTIONARY LNDG MADE AT CHARLOTTE DOUGLAS ARPT WITH NO INJURIES OR ACFT DAMAGE. MAINT INSPECTIONS SUBSEQUENTLY REVEALED INTERNAL FAILURE OF 'A' PHASE IN #1 GENERATOR AND THE FAILURE OF A PWR MODULE BEHIND THE CIRCUIT BREAKER PANEL. THIS TYPE OF FAILURE HAS NO ESTABLISHED EMER PROC AS THE INDICATIONS WERE CONTRADICTING EACH OTHER. OUR TRAINING CONTINUES TO INCLUDE 'VANILLA TYPE' MALFUNCTIONS BUT REALITY IS THAT WHEN FAILURES OCCUR THEY TEND TO BE COMPOUNDED BY OTHER FAILURES, BOTH HUMAN AND MECHANICAL WHICH FRUSTRATE THE CREW'S ATTEMPT TO SOLVE THE PROB.

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.