Narrative:

I was performing an operational test of the left/H (left hand) and right/H (right hand) engine fuel shutoff valves. I had armed the left/H and right/H engine fire bottles according to the task and went to ensure that the shutoff valves were closed. After which I had told fellow mechanic [name] to return to the cockpit to disarm the fire bottles; reminding him not to press the green switchlights beneath the fire push switchlights he was supposed to press. I had prepared to witness the shutoff valves close when I heard the sounds of the engine fire bottles discharging. Mechanic [name] had returned to me and I asked him which switch he had hit and he told me he had pressed both of the discharge switch/lights; confirming my suspicions. I returned to the cockpit and verified that the bottles had indeed discharged before pressing both fire push switchlights and completing my original task before dealing with the aftermath.I'm not too sure what more could be done to mitigate the issue other than a shield of some sort covering the discharge switch/lights.

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Original NASA ASRS Text

Title: Technician reported miscommunication during a functional check of the engine fuel shut off valves; resulting in the inadvertent discharge of both engines' fire bottles.

Narrative: I was performing an Operational Test of the L/H (Left Hand) and R/H (Right Hand) Engine Fuel Shutoff valves. I had armed the L/H and R/H engine fire bottles according to the task and went to ensure that the shutoff valves were closed. After which I had told fellow mechanic [NAME] to return to the cockpit to disarm the fire bottles; reminding him not to press the green switchlights beneath the FIRE PUSH switchlights he was supposed to press. I had prepared to witness the shutoff valves close when I heard the sounds of the engine fire bottles discharging. Mechanic [NAME] had returned to me and I asked him which switch he had hit and he told me he had pressed both of the discharge switch/lights; confirming my suspicions. I returned to the cockpit and verified that the bottles had indeed discharged before pressing both FIRE PUSH switchlights and completing my original task before dealing with the aftermath.I'm not too sure what more could be done to mitigate the issue other than a shield of some sort covering the discharge switch/lights.

Data retrieved from NASA's ASRS site 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.