Beechjet 400
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Commercial
Flight Crew Last 90 Days 61; Flight Crew Total 962; Flight Crew Type 115
Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Landing Without Clearance; Deviation / Discrepancy - Procedural Clearance; Flight Deck / Cabin / Aircraft Event Illness / Injury
Flight Crew Became Reoriented
Human Factors
We had an early departure. Upon meeting up with the Captain in hotel lobby and during preflight he appeared not well and very tired. He said he was just worn out from walking so much the day prior. I asked him if he was okay; to which he responded yes. We took off part 91 and about 10 min into the flight he advised me he wasn't feeling well all morning. As we approached class D airspace at 3;000 ft.; I advised slow to 200 kts for Delta airspace and PF (Pilot Flying) started coughing very hard; turning his head lifting mic and hand off yoke. I asked if he was ok and if he wanted me to land. He replied 'no; I am fine'. The coughing continued aggressively as we were turning inbound; we still had not started to slow to 200 kts. I advised '200 kts.' PF continued cough and patted his chest. I asked; 'are you ok?' He replied yes. I urged the PF that 'I think it would be best if I landed.' He said he was fine and continued.We continued approach and stabilized appropriately and PF's symptoms seemed to subside. I noticed after 30 flaps was selected we were at a very steep approach and it did not feel or seem right. I glanced out of the cockpit and saw the VASI lights indicated we were above glide slope. I quickly transitioned my eyes back inside the cockpit. Something did not make sense or add up as to why we were high and what seemed steeper than a 3 degree glide path; not quite a stable approach. I was checking the FMS and looking at my runway/ approach charts and wondered why something did not make sense. I completed the before landing checklist and called out altitudes for PF. We landed safely and turned off runway. It wasn't until we turned of the runway and ground control advised us we were at [the wrong airport]. The Captain looked at the PFD and realized we still had 4nm on the approach from our destination. After looking back at the situation and debriefing; we concluded that lack of communication (CRM) was a big factor along with illness and situational awareness. I also was distracted and not situational aware due to being concerned about the PF's illness when beginning the approach. I noticed an airport that 'looked' right and trusted the PF to be doing things correctly without completely crosschecking and verbalizing my concerns on being high or something not seeming right. I also should have called a go around. My corrective action moving forward is to brief myself and PF that surrounding airports in close proximity of the destination may cause confusion on arrival and be aware. Especially airports with the same runway configurations. I also learned to verbalize anything that may not seem stable or right on the approach. Had I mentioned we seem high it may have got him looking inside the cockpit and caught that we had 4 more miles. If better CRM was utilized more efficiently we probably would have avoided this safety issue.
BE400 First Officer reported distractions with the Captain's apparent illness resulted in landing at the wrong airport.