EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Total 7522
Distraction; Confusion
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Human Factors
While at cruise altitude I was using the calculator on my phone to determine fuel burn to the next waypoint. I was the non-flying pilot and ATC gave us a change of frequency. I placed the phone on my right leg and reached forward to change the frequency. The phone fell from my leg and onto the floor. I heard the phone hit the floor. I left it there and changed frequencies and checked in with ATC. I went to pick up my phone and while I was doing this the aircraft alerted us to the cabin pressure altitude climbing. I noticed we were depressurizing and so we performed our memory items and requested priority handling and initiated a descent. At this point the passenger oxygen masks were activated. As we were descending I realized the dump button was pressed and surmised that when the phone fell it must have hit the guarded dump switch; bent the guard causing the dump button to engage and begin depressurizing the cabin. When we leveled at 10;000 feet we continued the checklist. We were right over ZZZ airport so this is where we diverted to. Because we were overweight and the First Officer was new I took control of the aircraft and made a smooth landing with approximately 300 ft/min descent rate. We landed without further incident. Passengers reported they were fine and did not want medical attention.In retrospect I would put any equipment that I have in my hands down in the proper place prior to doing anything else in the cockpit.
While flying at FL250 we experienced a rapid depressurization. We accomplished our memory items and the captain requested priority handling and commenced a descent. We diverted to ZZZ; no passengers requested medical attention.The Captain had been using the calculator on his phone to calculate fuel between points. While making a fuel calculation; we received a radio call from ATC and the Captain put his phone on his leg. When he leaned forward; the phone slipped off his leg denting the Dump button guard and pressed the dump button.
EMB-145 flight crew reported Captains cell phone fell from his leg and hit the pressure dump switch; causing cabin depressurization.