Narrative:

I was flying a rental aircraft; and it was the aircraft's first flight since progressive maintenance. I had not flown for about a month. During taxi; I noticed an unusual smell in the cockpit; smelled of a cleaning agent or solvent. Assuming it was related to the recently completed maintenance; I ignored it. Shortly after takeoff; smell in cockpit became stronger. Climbing through 1;000 ft AGL; I noticed a light gray smoke coming from either under the front seats or beneath the panel. The smell did not seem to be a fuel or oil smell; so I assumed an electrical fire was a possibility. Declared an emergency to the tower; announced I was returning to land on 29; and that I'd be shutting off my radios. After shutting the radios and opening the storm window and fresh air vents; the smell and smoke seemed to subside. I was watching the tower for light gun signals; but never saw any. I made a left downwind; and tight base to final; landed; turned off on the taxiway. In front of me was the airport firefighting equipment and operations personnel. I shut down and left the plane while the firefighters checked it out; and gave my personal information to operations personnel. The flight school towed the plane to the maintenance hangar where I spoke with the chief mechanic. He suspected that some of the engine de-greasing solvent that they used during maintenance had dripped into the muffler shroud. Full power for takeoff generated enough heat for it to start burning off; so once I was moving fast enough; the airflow through the heater caused the smoke to enter the cockpit. It likely would have stopped on its own after 5 or 10 minutes. Tower and airfield personnel were very accommodating; tower cleared the runway as soon as I announced my intentions to return; and I was NORDO after that. It seems somewhat amiss to me that ordinary maintenance procedures can cause smoke in the cockpit; but now I know; and can identify the smell. In the future I will; if I see smoke but identify a similar smell; will instead remain near the airfield to see if it goes away on its own; instead of immediately declaring an emergency.

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Original NASA ASRS Text

Title: A PA-28 pilot declared an emergency and returned to land when a light gray chemical smelling smoke entered the cockpit after takeoff. Maintenance later said that a cleaning chemical on the exhaust manifold was the source.

Narrative: I was flying a rental aircraft; and it was the aircraft's first flight since progressive maintenance. I had not flown for about a month. During taxi; I noticed an unusual smell in the cockpit; smelled of a cleaning agent or solvent. Assuming it was related to the recently completed maintenance; I ignored it. Shortly after takeoff; smell in cockpit became stronger. Climbing through 1;000 FT AGL; I noticed a light gray smoke coming from either under the front seats or beneath the panel. The smell did not seem to be a fuel or oil smell; so I assumed an electrical fire was a possibility. Declared an emergency to the Tower; announced I was returning to land on 29; and that I'd be shutting off my radios. After shutting the radios and opening the storm window and fresh air vents; the smell and smoke seemed to subside. I was watching the Tower for light gun signals; but never saw any. I made a left downwind; and tight base to final; landed; turned off on the taxiway. In front of me was the Airport Firefighting equipment and Operations personnel. I shut down and left the plane while the firefighters checked it out; and gave my personal information to Operations personnel. The flight school towed the plane to the Maintenance hangar where I spoke with the Chief Mechanic. He suspected that some of the engine de-greasing solvent that they used during maintenance had dripped into the muffler shroud. Full power for takeoff generated enough heat for it to start burning off; so once I was moving fast enough; the airflow through the heater caused the smoke to enter the cockpit. It likely would have stopped on its own after 5 or 10 minutes. Tower and Airfield Personnel were very accommodating; Tower cleared the runway as soon as I announced my intentions to return; and I was NORDO after that. It seems somewhat amiss to me that ordinary maintenance procedures can cause smoke in the cockpit; but now I know; and can identify the smell. In the future I will; if I see smoke but identify a similar smell; will instead remain near the airfield to see if it goes away on its own; instead of immediately declaring an emergency.

Data retrieved from NASA's ASRS site as of July 2013 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.