Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Time Pressure; Communication Breakdown; Distraction; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Procedure; Human Factors
We were assigned to ferry an airplane. The aircraft was at the maintenance hangar and we closed the door and I armed the MCD (Main Cabin Door). When we started engine 1; we got an EICAS message that required a ground reset; which we could not clear. The message was Engine 1 short dispatch. Before maintenance came on the aircraft I disarmed the MCD. Maintenance fixed the issue but before they started the engine to troubleshoot the problem; they asked me to close the MCD. Out of habit; I armed the door and when they were done; I was sitting in 1A and one of the maintenance personnel opened the MCD as it was armed.
The Captain and I were assigned to ferry an Airplane which we picked from the maintenance hangar. We did our normal checks everything seemed great so we closed the door and started engine 1. After Engine 1 was started we got an EICAS message ENGINE 1 SHORT DISPATCH. We ran the [checklist] but the message didn't clear so we called dispatch and notified them then got transferred to maintenance who promptly came out to the airplane to assess the issue. Before maintenance Started to troubleshoot the engine they asked us to close the main Cabin door which the captain did and mistakenly armed the doors. I was sitting in 1B and didn't notice so I take responsibility also. One of the maintenance personnel opened the main cabin door and the slides came out due to them being armed.
E175 flight crew reported that; when arriving at the aircraft; maintenance failed to disarm door prior to opening it activating the slide.