Maricopa, AZ, USA
N6117X
Ayres S2R-G10
The airplane collided with the ground during aerial applications. En route to a field, the pilot related that the circuit breaker for the torque indicator popped. After it was reset, the pilot began his descent to the field and the torque indicator popped the circuit breaker for a second time. The pilot reset the breaker, and then the airplane impacted the ground. Post accident examination revealed that the insulation on the wiring to the torque meter had worn off, resulting in the circuit breaker tripping off line. The lower cowling contained pieces of the combustion liner, and a 1½-inch hole was located in the bottom of the combustion liner. The torque meter area displayed signatures consistent with extensive heat. An internal examination revealed aluminum and titanium deposits on the turbine blades, indicative of a running engine at the time of impact. No pre-existing condition was found on the engine that would have interfered with its normal operation.
On June 9, 2003, about 1515 mountain standard time, an Ayers S2R-G10, N6117X, collided with the ground, immediately prior to an aerial application near Maricopa, Arizona. Crop First Aviation, Inc., was operating the airplane under the provisions of 14 CFR Part 91. The commercial pilot, the sole occupant, sustained minor injuries; the airplane sustained substantial damage. The flight departed a private airstrip near Stanfield, about 1510. Day visual meteorological conditions prevailed, and no flight plan had been filed. In a telephone interview with the Safety Board investigator-in-charge (IIC), the pilot reported that shortly after takeoff, the torque indicator exceeded 100 percent. Then, the torque indicator circuit breaker popped. After resetting the circuit breaker, it popped a second time. All other components appeared to be operating normally. Approximately 2 miles from the crop field, the fuel flow indicator ceased operating. The engine then shutdown, "like it had been turned off." At 500 feet above ground level, an emergency landing to a field was initiated. In a written statement, the pilot reported that he loaded the airplane with fertilizer and departed for the crop application. During the climb out, the toque indicator popped the circuit breaker. After the breaker was reset, the torque indicator was working. As he started the descent to the field, the torque indicator popped the circuit breaker again. At that time, all gauges were in the green except for the torque indicator. The pilot reset the breaker for a second time and within 5 to 6 seconds the engine shut down. No noise or unusual vibration was noted. He immediately pushed the nose down and flared into a field, sliding approximately 100 feet. The engine failure occurred at an altitude of 300 to 400 feet agl. On June 26, 2003, the Federal Aviation Administration (FAA) inspector and a Honeywell representative, parties to the investigation, began an examination of the engine and its components. The lower cowling contained pieces of the combustion liner and a 1½-inch hole was located in the bottom of the combustion liner. The insulation on the wiring to the torque meter had worn off. The area of the torque meter displayed signatures consistent with extensive heat. Fuel was evident in various fuel lines that included, in part, those before and after the fuel shutoff valve and the fuel lines before and after the flow divider. Fuel was also present in the fuel control filter. The fuel shutoff valve was functionally tested and exhibited a 16 percent reduction per flow rate specifications. The fuel shutoff valve was disassembled; however, the source of the 16 percent reduction was not identified. Honeywell indicated that the 16 percent reduction would not result in a sudden engine stoppage. On August 28, 2003, the fuel flow divider, fuel control, and NTS checkout solenoid were functionally tested at Honeywell's facilities under the auspices of the FAA inspector. The fuel flow divider flowed 13 percent below fuel flow specifications. According to Honeywell, this reduction in flow would not impede the engine's ability to produce power during cruise flight. The fuel control and pump assembly tested nominal to high on power test points and nominal to low on idle and descent test points (Honeywell Engine SN P-37286C Report, Appendix B). The NTS checkout solenoid was leaking due to a damaged internal O-ring. A check valve had been installed in the system to prevent oil flowing back through the system in the event of a leak. On October 23, 2003 an engine teardown commenced with the IIC, the FAA inspector, and the Honeywell representative, present. Rotational scoring was present throughout the engine. All four ring gear assembly mounting dowels were bent counter-clockwise in the diaphragm housing. The suction sides of the vanes and the turbine stators and rotors exhibited metallic-like deposits. Four first-stage turbine nozzle vane segments and three first-stage turbine rotor blades were submitted for material analysis to identify the deposits. Honeywell issued a material analysis report on November 10, 2003 (Honeywell Engine SN P-37286C Report, Appendix A). The report concluded that the deposits on the vanes were determined to be rich in aluminum with silicon. The blade deposits consisted of both aluminum and titanium. In the Honeywell report issued on March 24, 2004, it concluded that no pre-existing condition was found on the engine that would have interfered with normal operation.
The pilot's failure to maintain clearance/altitude from terrain during an aerial application, which resulted in an in-flight collision with terrain. A factor associated with the accident is the pilot's diverted attention while resetting a circuit breaker.
Source: NTSB Aviation Accident Database
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