An EMB120 flight crew loses all of their primary AC power sources while on final approach to dfw, tx...

Attributes
ACN	534214
Time
Date	200112
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : dfw.airport
State Reference	TX
Altitude	agl bound lower : 1500 agl single value : 36
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tower : dfw.tower
Operator	common carrier : air carrier
Make Model Name	Brasilia EMB-120 All Series
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : commercial pilot : instrument
Experience	flight time last 90 days : 200 flight time total : 1100 flight time type : 200
ASRS Report	534214
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : critical non adherence : published procedure non adherence : company policies other anomaly other
Independent Detector	other flight crewa other flight crewb other other : 941
Resolutory Action	aircraft : automation overrode flight crew controller : separated traffic flight crew : diverted to alternate
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Airline flight (EMB120) to dfw. Both the captain and I were both aware that the left generator was deferred and that the MEL called for the APU to remain running. After takeoff, I called for the after takeoff check and the captain complied. Out of habit, the captain inadvertently shut down the APU. I was established on a 3-4 mi final (runway 36L at dfw) when the electrical power failed due to the second main generator failing. The aircraft automatically went into emergency power. The captain took command of the aircraft and landed at dfw without incident. After clearing runway 36L at dfw it was noted that the APU had inadvertently been shut down.

Original NASA ASRS Text

Title: AN EMB120 FLC LOSES ALL OF THEIR PRIMARY AC PWR SOURCES WHILE ON FINAL APCH TO DFW, TX.

Narrative: AIRLINE FLT (EMB120) TO DFW. BOTH THE CAPT AND I WERE BOTH AWARE THAT THE L GENERATOR WAS DEFERRED AND THAT THE MEL CALLED FOR THE APU TO REMAIN RUNNING. AFTER TKOF, I CALLED FOR THE AFTER TKOF CHK AND THE CAPT COMPLIED. OUT OF HABIT, THE CAPT INADVERTENTLY SHUT DOWN THE APU. I WAS ESTABLISHED ON A 3-4 MI FINAL (RWY 36L AT DFW) WHEN THE ELECTRICAL PWR FAILED DUE TO THE SECOND MAIN GENERATOR FAILING. THE ACFT AUTOMATICALLY WENT INTO EMER PWR. THE CAPT TOOK COMMAND OF THE ACFT AND LANDED AT DFW WITHOUT INCIDENT. AFTER CLRING RWY 36L AT DFW IT WAS NOTED THAT THE APU HAD INADVERTENTLY BEEN SHUT DOWN.

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.