Date: 201310
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Physiological - Other; Fatigue; Confusion; Distraction; Communication Breakdown
Second reporter function: Pilot Not Flying; Captain
Anomaly: Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Flight Deck / Cabin / Aircraft Event Illness / Injury
Detector: Person Flight Crew; Person Other Person
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Executed Go Around / Missed Approach; General Physical Injury / Incapacitation
Contributing factors: Human Factors; Environment - Non Weather Related; Company Policy; Aircraft
Primary problem: Ambiguous

Narrative: I was the pilot flying as we were being vectored Approach Control for 22. We were on a heading but I don't remember what it was. I heard ATC say to turn to a heading of 170 so I turned the heading knob to that heading as the autopilot was engaged. I do not recall what the Captain read back only what I heard and therefore did. They told us to turn to a 090 heading but changed it to a west heading. We were vectored around again for another approach. There was no loss off separation. Upon landing we were told to call ATC. There were other aircraft with flight numbers that were close to ours as well; so that may have added to my confusion. So I am still replaying it in my mind trying to figure out how I could have got it so wrong.  Later in the day; I was advised to go get tested for possible Carbon Monoxide contamination.  I went to the hospital late that night and was tested positive for 'Carbon Monoxide Exposure' as this is how it reads on my discharge paperwork. The Doctor said my readings were elevated at that time of night which was very late that night; 12+ hours later; and would have been much higher at the time of this event but who knows how high it was. I did not know at the time about the Carbon Monoxide. It sneaks up on you without you knowing you are being affected as it did to us. So watch out for each other. This is very rare in planes. I think but maybe a Carbon Monoxide monitor installed in the cockpit might be a good option.

Callback: The reporter stated he flew the same aircraft on a series of flights that day. He did not recognize any symptoms at the time; other than fatigue as evidenced by continual yawning. The Captain had himself removed from flight because he could not concentrate nor comprehend some of what was occurring and suspected he was not suitable for continued work. The Captain went to an ER and tested high for Carbon Monoxide. He called the reporter; his First Officer; who had flown an additional four legs. He was then removed from flying and tested Carbon Monoxide positive at the ER about two hours after landing; which would have been more than twelve hours since his first flight earlier that morning.The aircraft continued flying even after the Captain reported his test results. The reporter is concerned that should the pilots become incapacitated because of Carbon Monoxide poisoning; the aircraft could continue flying to fuel exhaustion because the Flight Station door lock is digital with no key available.The reporter had previously talked to a Captain who had experienced Carbon Monoxide poisoning and had hearsay reports that the exposure had happened to one other of his airline's crews and another air carrier's crew flying the same aircraft type.

Second narrative: We were notified to contact Approach after we landed to provide details of event. I should have caught the turn past 070; whatever the reasoning may have been. There were many similar sounding call signs in the area that myself and/or the First Officer may have mistaken for our own.After landing I assessed my mental and physical condition. I felt that I was no longer suitable to fly and removed myself from duty. A couple hours later I was still not feeling well so I went to my Doctor. They ran some blood work and found that my carbon monoxide levels were above normal and were consistent with carbon monoxide poisoning. This may have had a significant affect on me and my first officer understanding and complying with the ATC instructions and ultimately the heading deviation.


Synopsis: A CRJ-200 flight crew reported they experienced a heading deviation during approach to destination. Post flight; the Captain reported he was unable to concentrate feeling unfit physically and mentally for the next flight; and decided to remove himself from duty.  Captain went to the Doctor and blood test results were consistent with Carbon Monoxide poisoning; which could have been a contributing factor in the heading deviation.  First Officer flew four additional legs before he was called and removed from flying; he also tested positive for Carbon Monoxide.