A B747-400 during scheduled maintenance has the #1R door escape slide inadvertently deployed.

Attributes
ACN	432244
Time
Date	199903
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B747-400
Operating Under FAR Part	Part 121
Flight Phase	ground : parked ground : maintenance
Flight Plan	None
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
Qualification	technician : airframe technician : powerplant
Experience	maintenance technician : 6
ASRS Report	432244
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance
Independent Detector	other other : person 1
Resolutory Action	other
Consequence	other
Factors
Maintenance	contributing factor : weather performance deficiency : testing performance deficiency : scheduled maintenance
Supplementary
Problem Areas	Environmental Factor Maintenance Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

I was performing a garth bar operations check of our #3 service doors are armed and disarmed a couple of times and then check that garth bar lock tabs are engaged properly. It was. Then I somehow forgot to disarm and opened the door. (It was hot inside aircraft. I was given the whole inside check to do. Normally 2 people do the check and we start the check at gate but were short manpwr.) the slide opened, fully deploying. I do not know how I could forget. I've done this check many times -- 100 or more. These are not excuses, but if the aircraft wasn't so hot I would not opened door, if I was not asked to do whole job maybe not tried to work or rushed nor have been thinking on how the heat would hinder my work. This is door 1R. I just forgot. There wasn't aircraft damage other than slide deployed and thus need to be replaced, it was done on next shift and was released for scheduled service.

Original NASA ASRS Text

Title: A B747-400 DURING SCHEDULED MAINT HAS THE #1R DOOR ESCAPE SLIDE INADVERTENTLY DEPLOYED.

Narrative: I WAS PERFORMING A GARTH BAR OPS CHK OF OUR #3 SVC DOORS ARE ARMED AND DISARMED A COUPLE OF TIMES AND THEN CHK THAT GARTH BAR LOCK TABS ARE ENGAGED PROPERLY. IT WAS. THEN I SOMEHOW FORGOT TO DISARM AND OPENED THE DOOR. (IT WAS HOT INSIDE ACFT. I WAS GIVEN THE WHOLE INSIDE CHK TO DO. NORMALLY 2 PEOPLE DO THE CHK AND WE START THE CHK AT GATE BUT WERE SHORT MANPWR.) THE SLIDE OPENED, FULLY DEPLOYING. I DO NOT KNOW HOW I COULD FORGET. I'VE DONE THIS CHK MANY TIMES -- 100 OR MORE. THESE ARE NOT EXCUSES, BUT IF THE ACFT WASN'T SO HOT I WOULD NOT OPENED DOOR, IF I WAS NOT ASKED TO DO WHOLE JOB MAYBE NOT TRIED TO WORK OR RUSHED NOR HAVE BEEN THINKING ON HOW THE HEAT WOULD HINDER MY WORK. THIS IS DOOR 1R. I JUST FORGOT. THERE WASN'T ACFT DAMAGE OTHER THAN SLIDE DEPLOYED AND THUS NEED TO BE REPLACED, IT WAS DONE ON NEXT SHIFT AND WAS RELEASED FOR SCHEDULED SVC.

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.