Narrative:

While climbing to my cruising altitude after departing ZZZ1; and contacting approach for VFR flight following; I noticed the strong smell of what I thought was exhaust fumes. I began a scan of all my engine information (all engine systems and sensors reporting safe and normal operation); my aircraft's carbon monoxide detector (no indication of co present) and visually checking the cockpit. Upon looking beneath the pilot and copilots panels; near the rudder pedals; I saw grayish smoke. I immediately contacted approach and informed them that I had smoke in the cockpit and that I was planning to land at ZZZ. My reasoning being that if emergency services were required should the situation worsen; ZZZ would likely have the better assets and response compared to turning back to ZZZ1; an unattended airfield. I then moved my air vents on the doors of the aircraft to provide ventilation to the cockpit; and confirmed that no cabin heating was on. No fire was observed. From my recollection; [approach] promptly acknowledged my transmission and asked if there was anything they could help with further. [Approach] then provided the airfield's position; distance; and weather. I was cleared to land straight-in for runway 7 shortly before being handed off to ZZZ tower. While speaking with the tower; I noticed that the smoke appeared to have dissipated (possibly due to nose down/lower power setting; I was unsure at the time) and informed tower that I should be able to exit the runway at the first taxiway. I was able to land the aircraft normally given the circumstances and exit the runway. Upon clearing the runway and taxiway I began my shutdown procedures and exited the aircraft promptly. Firefighters approached and evaluated the aircraft and my condition. Upon opening the cowling and looking at the engine the exhaust system appears to have cracked and failed. A large piece of the exhaust down pipe appears to have broken off and the exhaust fumes collected in the engine compartment; likely resulting in the smoke I saw in the cockpit. I did not declare an emergency; but one was declared on my behalf. I was able to land safely and no one was injured. This experience has given me serious doubts regarding honest communication of an in-flight issue with controllers if the outcome is this burden of information and reports. Thank you for your time and for this program.

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Original NASA ASRS Text

Title: GA Pilot reported smoke accompanied by strong exhaust fumes in the cockpit during initial climb.

Narrative: While climbing to my cruising altitude after departing ZZZ1; and contacting Approach for VFR Flight Following; I noticed the strong smell of what I thought was exhaust fumes. I began a scan of all my engine information (all engine systems and sensors reporting safe and normal operation); my aircraft's carbon monoxide detector (no indication of CO present) and visually checking the cockpit. Upon looking beneath the pilot and copilots panels; near the rudder pedals; I saw grayish smoke. I immediately contacted Approach and informed them that I had smoke in the cockpit and that I was planning to land at ZZZ. My reasoning being that if emergency services were required should the situation worsen; ZZZ would likely have the better assets and response compared to turning back to ZZZ1; an unattended airfield. I then moved my air vents on the doors of the aircraft to provide ventilation to the cockpit; and confirmed that no cabin heating was on. No fire was observed. From my recollection; [Approach] promptly acknowledged my transmission and asked if there was anything they could help with further. [Approach] then provided the airfield's position; distance; and weather. I was cleared to land straight-in for Runway 7 shortly before being handed off to ZZZ Tower. While speaking with the Tower; I noticed that the smoke appeared to have dissipated (possibly due to nose down/lower power setting; I was unsure at the time) and informed Tower that I should be able to exit the runway at the first taxiway. I was able to land the aircraft normally given the circumstances and exit the runway. Upon clearing the runway and taxiway I began my shutdown procedures and exited the aircraft promptly. Firefighters approached and evaluated the aircraft and my condition. Upon opening the cowling and looking at the engine the exhaust system appears to have cracked and failed. A large piece of the exhaust down pipe appears to have broken off and the exhaust fumes collected in the engine compartment; likely resulting in the smoke I saw in the cockpit. I did not declare an emergency; but one was declared on my behalf. I was able to land safely and no one was injured. This experience has given me serious doubts regarding honest communication of an in-flight issue with controllers if the outcome is this burden of information and reports. Thank you for your time and for this program.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.