Pitts Model 12 accident near Burneyville, Oklahoma, April 18, 2015

The NTSB's narrative final · quoted from the NTSB record

The commercial pilot reported that, after a short local flight, he entered the traffic pattern on the downwind leg and reduced the engine power to reduce airspeed. He subsequently reduced the engine power again when the airplane was abeam the approach end of the runway. During the base leg, he determined that the airplane would require additional engine power to land at his preferred touchdown point on the runway; however, the engine did not respond when he advanced the throttle. He subsequently increased both the throttle and propeller controls with no noticeable change in engine power. The airplane did not have enough altitude to reach the runway, so the pilot made a left 90° turn from the final approach path toward an open wheat field for a forced landing. He stated that the airplane came to rest nose down after both main landing gear collapsed upon landing in soft, muddy terrain. Postaccident engine examination revealed no evidence of a mechanical failure that would have precluded normal operation. The main fuel tank contained ample fuel; however, water and various debris were found in the main fuel line, line fitting, and the inline fuel filter. The observed contamination of the fuel system likely resulted in a partial loss of engine power. It could not be determined whether the vent inlet became blocked during the accident or was blocked before the accident and caused the partial loss of engine power.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.