Citation I (C500)
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Workload; Communication Breakdown; Troubleshooting; Time Pressure; Human-Machine Interface
Aircraft Equipment Problem Critical; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem; Flight Crew Took Evasive Action
Human Factors; Aircraft
While in cruise at FL340 the right engine suddenly shutdown. Concerned about losing pressurization; the Captain had me [notify ATC] and request lower. The Captain disconnected the Autopilot and descended for lower. I dawned my O2 mask. I then took the controls while he attempted to put on his mask. While I was hand flying; the Captain was having trouble getting his mask on. Simultaneously; ATC was attempting to obtain information from us regarding the [situation] but despite the mic switch in the mask position; ATC was unable to hear my radio transmissions. After the Captain got his mask on he made several attempts to speak with ATC with no success as well. Seeing the Captain was unable to reach ATC; I proceeded to adjust my headset mic just below my mask; switched the mic switch back to headset and pulled my mask off to make radio transmissions then place the mask back on. With all the distractions we managed to get slightly right of course as the aircraft tended to yaw into the dead engine. About the time I noticed and started correcting; ATC alerted us we were off course. I responded that we were aware and already started correcting. Due to the mask/mic issue; ATC repeated their transmission and heard my reply the second time and we got back on course. By this time the Captain was situated and took the controls back. We then coordinated with ATC to choose a proper/nearest airport to land. ATC set us up for vectors for the RNAV and we landed without incident.The primary cause for the deviation was the yaw out of trim. Contributing factors were the distraction caused by inability to communicate with ATC through the mask mic with the Captain's struggle to dawn his mask and failed attempt to communicate with ATC through his mask as a secondary contributing factor. Going forward; when a control handoff occurs during an engine out I will confirm proper rudder trim has been set. Prior to flight in an aircraft I have not been in before and/or as part of a periodic check in an aircraft I fly regularly; I will conduct a radio check with the mask mic to insure the ability to communicate during an emergency requiring the O2 mask.
C500 First Officer reported an engine loss at cruise led to flight crew communication and navigation issues.