Thrush Aircraft INC S2R-H80 accident near Gypsum, Kansas, May 5, 2017

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

The commercial pilot stated that, after completing a portion of a low-level agricultural application flight, the engine power decreased "significantly." The pilot pushed the power lever full forward, but the engine did not respond. He made several more passes to get more weight off the airplane to see if the engine would regain power; however, engine power did not increase, so the pilot flew the airplane back toward the departure airport. The pilot tried to climb the airplane but there was insufficient power to do so, and he then saw smoke coming out both exhausts. The engine then lost all power. Subsequently, the pilot conducted a forced landing in a field, and the airplane slid through a fence and then stopped, which resulted in substantial damage to the fuselage. A review of data downloaded from the engine monitor revealed engine operation consistent with a fuel interruption and a subsequent loss of engine power. During postaccident examination, the main electric fuel boost pump was found operational. However, it did not meet standard acceptance test criteria. The engine was not test run; however, component level testing of the fuel control unit, the emergency electric fuel pump, and the starting and limiting unit revealed no anomalies that would have prevented normal operation. Thus, the reason for the interruption in fuel flow and the subsequent loss of engine power could not be determined. However, the airplane manufacturer has subsequently developed a redesign and has issued a service bulletin to address the fuel system, including electric fuel pumps and plumbing. The Airplane Flight Manual (AFM) contained a Failure of Automatic Fuel Scheduling checklist, and the first step of this checklist was to engage the emergency governor. The pilot reported that he did not follow these procedures when the engine power decreased. Further, the AFM contained an Engine Failure In-Flight checklist, and the first step of the checklist was to dump the hopper. The pilot reported that he did not dump the hopper when the engine lost power. The pilot's failure to subsequently follow the emergency procedures to recover engine power likely necessitated the forced landing.

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.

Photographs from the investigation 17 pictures from the NTSB's docket, as the NTSB released them

Photo 1 – View of the wreckage, damaged fence, and ground scar.Photo 2 - Quartering view of the wreckage that shows substantial damage to left wing.Photo 3 - Side view of the wreckage that shows substantial damage to left wing.Photo 4 - View of the instrument panel with the MVP-50 powered up.Photo 5 - View of the instrument panel with the MVP-50 powered up.Photo 7 - View of the filter.Photo 8 - View of the electric fuel pump installation.Photo 11 - View of red colored media found in the threaded portion of the fuel pump.Photo 12 - View of the fuel pump showing the separated grounding connector.Photo 13 - View of the fuel pump as connected to the test bench.Photo 14 - View of a seat within the fuel pump.Photo 15 - View of the vanes within the fuel pump.Photo 16 - View of disassembled pump vanes.Photo 17 - View of the fuel pump armature.Photo 18 - View of remaining portion of brush block and springs.Photo 19 - View of the emergency pump as connected to the test bench.Photo 20 - View of the emergency pump's armature.

The NTSB's photographs with the NTSB's captions, at screen size. Open a picture to see it full size or to report one that should not be shown.