SEA96LA102

The pilot reported that while maneuvering for an aerial application run at about 100 feet above ground level, the airplane started to sink and that he added power, but the engine did not respond. The pilot attempted to avoid obstructions, but the airplane subsequently struck a fence and crashed into a cultivated area. Witnesses reported 'sputter', 'back fire [sic]', and 'cutting in and out' noises from the engine. Postaccident examination revealed little to no damage to the three propeller blades. The pilot reported that he took off with full fuel and that the accident occurred 10 minutes after takeoff. Fuel was found in one of the two interconnected main tanks at the crash scene; the other main tank was empty, but the wing containing that tank was substantially damaged. In a postaccident test run, the engine operated successfully with normal fuel pressure and turbocharger operation, after the electric boost pump was primed. After the boost pump was subsequently turned off, the engine continued to run normally, using the engine-driven fuel pump.

On May 30, 1996, approximately 0745 mountain daylight time, a Cessna T188C, N9980J, received substantial damage in a collision with a fence and subsequent collision with terrain following a loss of engine power near Hooper, Utah. The airline transport pilot-in-command of the single-seat agricultural aircraft was not injured. The aircraft was on a local 14 CFR 137 agricultural application flight from Ogden, Utah. Visual meteorological conditions prevailed and no flight plan had been filed.

According to the pilot's accident report, the accident occurred 10 minutes after takeoff from Ogden and he had taken off with a full fuel load of 54 gallons. The pilot reported: "I pulled up from a run from north to south [and] started my turn back to the field. In the turn I felt the airplane start to sink so I added more power but there was no response. (This [occurred] at [approximately] 100 [feet above ground level] on a heading of west.) At this point I had 1 notch of flaps [and] full power. There was no buffet. I put the nose down, straightened the wings [and] went through a pole fence...." According to a Weber County sheriff's report of the accident, the pilot stated to sheriff's deputies that shortly before impact, he "increased his angle of bank to avoid several trees and a residence...it was at this point the wingtip clipped a wooden fence, and continued into a plowed garden area...." A witness to the crash told sheriff's deputies that she heard a "sputter like a back fire [sic] and an unusual sound." Another witness stated that "the engine seemed to cut in and out and had a putt, putt sound."

The report of the FAA inspector who responded to the crash site stated that "the props (3) showed little or no damage." The FAA inspector reported that the aircraft's right wing tank contained no fuel (however, the underside of the right wing was substantially damaged), and that the left wing tank contained fuel to about 1/2 inch below the top of the fuel filler. According to the airplane flight manual, the airplane fuel system is comprised of two wing tanks (one in each wing), which feed a common reservoir tank; i.e. the two wing tanks are interconnected via the reservoir tank. The fuel system is controlled by a two-position (on/off) fuel shutoff control in the cockpit. The fuel shutoff valve is located between the reservoir tank outlet and the engine.

The accident aircraft's engine, a Continental TSIO-520-T, was test run on June 10, 1996. An FAA inspector who attended the engine test reported that the engine started and ran after priming the boost pump, and that the engine subsequently ran on the engine fuel pump when the boost pump was turned off. He stated that "fuel pressure was normal and the turbo charger [sic] operated normally."

According to aircraft maintenance records, the engine was overhauled in October 1992 after experiencing a broken crankshaft. The engine logbook indicated that on March 31, 1995, 308.1 flight hours after overhaul, the engine was "removed from [the aircraft] and disassembled for sand in crankcase damage", then subsequently reassembled with several new and reconditioned parts and reinstalled on the aircraft. The operator indicated that the engine had 439 hours since overhaul at the time of the accident. The engine logbook also indicated that a 100 hour inspection was performed on March 22, 1996, at 405.5 hours since overhaul.