Light Transport; Low Wing; 2 Turboprop Eng
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 40; Flight Crew Total 2550; Flight Crew Type 450
Situational Awareness; Communication Breakdown
Flight Deck / Cabin / Aircraft Event Illness / Injury
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Diverted; Flight Crew Landed As Precaution; Flight Crew Took Evasive Action; General Physical Injury / Incapacitation
Human Factors
On the incident date; I was the pilot not flying on a crewed aircraft. The pilot flying told me before the flight that he hadn't slept good the night before and thought that it might have been something he ate. It was agreed that he would fly the first leg and I would fly the last two legs of the day as we are both rated on the airplane. As we began to level off at FL250 with the autopilot engaged; the pilot flying told me that he thought he was going to be sick and asked me to get him a trash can. I retrieved one from the cabinet behind our seats. Just as I handed him the small can; he began vomiting uncontrollably all over the cockpit and then slumped back in his seat unconscious. I told one of passengers that I needed assistance in the cockpit. The passenger came to the cockpit as the sickened pilot regained consciousness and began throwing up again. I disengaged the autopilot and began an emergency descent from the right seat while contacting ATC. As luck would have it; the Controller took a while to answer as he was on the landline. I [advised ATC of] the other pilot's incapacitation and that I needed vectors to the nearest airport. During this time; the passenger assisted in helping the sick pilot who went in and out of consciousness. I told ATC to have medical personnel enroute to the non-towered airport which was approximately 12 miles west of our location. It took about 12 minutes to descend from FL250 and then land at the airport. Medical personnel arrived shortly after landing and the sickened pilot was transported to the hospital. The pilot who became sick was diagnosed with atrial fibrillation which caused the episode. He had no prior history of heart problems. We were fortunate that there were two of us in the cockpit. ATC was extremely helpful during the event. The event was an eye opener as we all train for rapid decompression emergency events and even pilot incapacitation scenarios but I never would have imagined what happened in our situation.
Pilot of a turboprop aircraft reported diverting to an alternate airport after the other pilot became incapacitated.