Commercial Fixed Wing
Maintenance Airframe; Maintenance Powerplant
Time Pressure; Troubleshooting; Confusion; Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Flight Crew Overcame Equipment Problem
Human Factors; Aircraft
On date; I was assigned Aircraft X as a return to gate for aft lavs clogged.  I was assigned by myself. The aircraft was full of passengers and the main reason I wanted the door open was to get rid of the bag of urine soaked paper towels I had removed from both lavs.  I didn't want to carry that bag thru the cabin and have the passengers smell or see it.  Thinking about this issue and knowing the flight was outbound I lost focus and opened the door.  Met Aircraft X at gate fully loaded with passengers and flight crew.  I unclogged the lavs and having a large pile of paper towels stuffed in both lavs; I didn't want to walk thru the cabin full of passengers.  I inadvertently armed L4 and immediately opened L4 door causing the slide to deploy.
Maintenance Technician reported inadvertently arming a door; then opening it; causing the slide to deploy.