A C401 declared an emergency and diverted due to loss of all electrical power.

Attributes
ACN	369085
Time
Date	199705
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : mwl
State Reference	TX
Altitude	msl bound lower : 6000 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zfw
Operator	common carrier : air carrier
Make Model Name	Cessna 401
Operating Under FAR Part	Part 135
Flight Phase	cruise other other other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : commercial pilot : cfi
Experience	flight time last 90 days : 170 flight time total : 1630 flight time type : 145
ASRS Report	369085
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa other other : unspecified cockpit
Resolutory Action	flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

Lost all electrical power, reported this to center, thought I had enough battery power to make it to destination. However, did not. Requested direct to abi. ZFW cleared me direct to abi. It was VMC, so I descended and landed. However, abi tower said 'because I was off the airway (being vectored) and transponder and radios were not working, ZFW declared it an emergency.' I feel even though center could not track me on radar or talk to me, it was VFR and not an emergency in my mind, otherwise I would have declared one. Callback conversation with reporter revealed the following information: the reporter stated the cause of the failure was the overvoltage regulator which is common to both left and right electrical system. He stated maintenance replaced both the left and right generators, left and right voltage regulators and the single overvoltage regulator. He stated cessna models 402 now have 2 overvoltage regulators to prevent the loss of all electrical power.

Original NASA ASRS Text

Title: A C401 DECLARED AN EMER AND DIVERTED DUE TO LOSS OF ALL ELECTRICAL PWR.

Narrative: LOST ALL ELECTRICAL PWR, RPTED THIS TO CTR, THOUGHT I HAD ENOUGH BATTERY PWR TO MAKE IT TO DEST. HOWEVER, DID NOT. REQUESTED DIRECT TO ABI. ZFW CLRED ME DIRECT TO ABI. IT WAS VMC, SO I DSNDED AND LANDED. HOWEVER, ABI TWR SAID 'BECAUSE I WAS OFF THE AIRWAY (BEING VECTORED) AND XPONDER AND RADIOS WERE NOT WORKING, ZFW DECLARED IT AN EMER.' I FEEL EVEN THOUGH CTR COULD NOT TRACK ME ON RADAR OR TALK TO ME, IT WAS VFR AND NOT AN EMER IN MY MIND, OTHERWISE I WOULD HAVE DECLARED ONE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE CAUSE OF THE FAILURE WAS THE OVERVOLTAGE REGULATOR WHICH IS COMMON TO BOTH L AND R ELECTRICAL SYS. HE STATED MAINT REPLACED BOTH THE L AND R GENERATORS, L AND R VOLTAGE REGULATORS AND THE SINGLE OVERVOLTAGE REGULATOR. HE STATED CESSNA MODELS 402 NOW HAVE 2 OVERVOLTAGE REGULATORS TO PREVENT THE LOSS OF ALL ELECTRICAL PWR.

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.