A B757-200 captain; electrically powering up a dead aircraft for preflight; inadvertently deployed t...

Narrative:

I entered the cockpit for preflight and the aircraft was completely shutdown; with no electrics at all. I checked the maintenance status and it was clean. I used the checklist to perform the safety and power on procedure: maintenance status/checked; bat switch/on...I reached up to turn on the battery; found the cover; lifted it and pressed. [Unfortunately;] I had pressed the RAT switch instead of the bat switch and the RAT dropped. Certainly; inattention to detail was the paramount cause. It should be noted; however; that [most] airplanes in our fleet; have a cover over the bat switch just like the RAT switch. Only the three merging partner aircraft do not. We routinely shut down an aircraft battery at night by lifting the cover and turning the bat switch off. So we lift the covers a lot. So; in my carelessness; I was looking for a cover to lift to turn on the bat and lifted the RAT instead. My aircraft that day did not have a cover over the bat switch! We need to stress in training the similarity of the switches. Plus; we should put covers on the aircraft that do not have them.

Original NASA ASRS Text

Title: A B757-200 Captain; electrically powering up a dead aircraft for preflight; inadvertently deployed the RAT believing the 'covered' RAT switch to have been the BAT switch.

Narrative: I entered the cockpit for preflight and the aircraft was completely shutdown; with no electrics at all. I checked the maintenance status and it was clean. I used the checklist to perform the Safety and Power On procedure: Maintenance Status/Checked; BAT Switch/ON...I reached up to turn on the battery; found the cover; lifted it and pressed. [Unfortunately;] I had pressed the RAT switch instead of the BAT switch and the RAT dropped. Certainly; inattention to detail was the paramount cause. It should be noted; however; that [most] airplanes in our fleet; have a cover over the BAT switch just like the RAT switch. Only the three merging partner aircraft do not. We routinely shut down an aircraft battery at night by lifting the cover and turning the BAT switch off. So we lift the covers a lot. So; in my carelessness; I was looking for a cover to lift to turn on the BAT and lifted the RAT instead. My aircraft that day did not have a cover over the BAT switch! We need to stress in training the similarity of the switches. Plus; we should put covers on the aircraft that do not have them.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1082958
Time
Date	201304
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	Parked
Flight Plan	IFR
Component
Aircraft Component	Hydraulic Auxiliary System Ram Air Turbine (RAT)
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy

A B757-200 captain; electrically powering up a dead aircraft for preflight; inadvertently deployed the RAT believing the 'covered' RAT switch to have been the bat switch.