Narrative:

Aircraft X; an experimental aircraft; had been under restoration for 10 years; new fabric; propeller; engine; every nut and bolt. On departure from runway xx at ZZZ on first test flight; the engine lost RPM from 2;500 to 1;600 at 150 ft AGL. I elected to declare an emergency with tower and sidestepped to land on the center parallel taxiway since there was insufficient stopping distance on the departure runway. Stopped aircraft on taxiway; which was completely unoccupied with 2;000 ft remaining after stopping. Taxiway is a lot longer than runway. No damage to aircraft or airport property. Problem traced to a filter element in gascolator not suitable for gravity feed fuel system. Manufacturer notified via phone of our problem.

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Original NASA ASRS Text

Title: The pilot of an experimental aircraft reported an engine failure after takeoff. After declaring an emergency he elected to land straight ahead on an unoccupied taxiway.

Narrative: Aircraft X; an experimental aircraft; had been under restoration for 10 years; new fabric; propeller; engine; every nut and bolt. On departure from Runway XX at ZZZ on first test flight; the engine lost RPM from 2;500 to 1;600 at 150 FT AGL. I elected to declare an emergency with Tower and sidestepped to land on the center parallel taxiway since there was insufficient stopping distance on the departure runway. Stopped aircraft on taxiway; which was completely unoccupied with 2;000 FT remaining after stopping. Taxiway is a lot longer than runway. No damage to aircraft or airport property. Problem traced to a filter element in gascolator not suitable for gravity feed fuel system. Manufacturer notified via phone of our problem.

Data retrieved from NASA's ASRS site as of April 2012 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.