On taxi in APU fails to start but captain shuts down left engine. Taxiway excursion.

Attributes
ACN	276986
Time
Date	199407
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : shv
State Reference	LA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zma
Operator	common carrier : air carrier
Make Model Name	Brasilia EMB-120 All Series
Operating Under FAR Part	Part 135
Flight Phase	ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 2700 flight time type : 700
ASRS Report	276986
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : far other anomaly other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : insufficient time
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

After landing while taxiing to the terminal, I tried to start the APU. On the first attempt it did not start. As I was attempting to restart the APU, the captain shut down the left engine. We had a complete electrical failure, thus losing nosewheel steering and control of the airplane. The left landing gear and nosewheel departed the taxiway before we could get the aircraft stopped. This problem has occurred on the emb 120 before. As the first officer, I should have noticed that the captain was shutting down the engine while I was starting the APU. He thought that the APU started and I failed to tell him it didn't and was attempting a restart.

Original NASA ASRS Text

Title: ON TAXI IN APU FAILS TO START BUT CAPT SHUTS DOWN L ENG. TXWY EXCURSION.

Narrative: AFTER LNDG WHILE TAXIING TO THE TERMINAL, I TRIED TO START THE APU. ON THE FIRST ATTEMPT IT DID NOT START. AS I WAS ATTEMPTING TO RESTART THE APU, THE CAPT SHUT DOWN THE L ENG. WE HAD A COMPLETE ELECTRICAL FAILURE, THUS LOSING NOSEWHEEL STEERING AND CTL OF THE AIRPLANE. THE L LNDG GEAR AND NOSEWHEEL DEPARTED THE TXWY BEFORE WE COULD GET THE ACFT STOPPED. THIS PROB HAS OCCURRED ON THE EMB 120 BEFORE. AS THE FO, I SHOULD HAVE NOTICED THAT THE CAPT WAS SHUTTING DOWN THE ENG WHILE I WAS STARTING THE APU. HE THOUGHT THAT THE APU STARTED AND I FAILED TO TELL HIM IT DIDN'T AND WAS ATTEMPTING A RESTART.

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.