Cirrus SR22 N151SR

The pilot stated that the preflight inspection and engine runup revealed no anomalies and the takeoff, climb, and initial portion of cruise were routine. He noted that the engine missed briefly about halfway through the flight. However, as the flight progressed, the engine sputtered briefly and then lost power completely, although the propeller continued to windmill. The pilot reported he cycled the ignition thinking that the issue might be ignition related since it had been recently serviced. He recalled that the engine stopped just after he turned off the left magneto and did not restart when it was switched back on. He added that the right magneto shut down briefly. He activated the fuel boost pump and switched fuel tanks but his efforts to restore engine power were not successful. The pilot activated the airframe parachute, and the airplane touched down in a corn field. Engine data recovered from the onboard avionics appeared stable throughout the flight until about 70 seconds before the accident. At that time, the engine fuel flow decreased to zero over a 26-second interval. The exhaust gas temperatures also began to decrease. Then, about 54 seconds before the accident, the engine speed began to decrease from 2,600 rpm until it reached 1,360 rpm. During the postaccident examination, no anomalies with respect to the airframe or engine fuel systems was observed and, according to recovery personnel, both fuel tanks contained useable fuel. The airplane was equipped with dual electronic ignition systems. The postaccident examination revealed that the fuse powering the right ignition controller module was open, which rendered the right ignition system inoperative. No preimpact anomalies were observed with respect to the left ignition system, nor any anomalies with respect to the fuel system or the engine assembly itself. The investigation was unable to determine exactly why the engine missed during the flight or why the fuse was tripped. One possibility is that the engine missed when the fuse tripped, and the right ignition system became inoperative. At that point, the engine continued to operate on the remaining ignition system. When the pilot cycled off the left ignition system to troubleshoot the cause of the engine miss, he inadvertently shut off the only remaining ignition system, resulting in a total loss of engine power. The pilot’s attempt to determine if the anomaly was ignition system related by isolating one system and then the other was reasonable. Because the ignition system fuses were installed behind the cockpit circuit breaker panel, the pilot was unable to detect the tripped fuse and determine that the right ignition system was inoperative. However, the engine should have been able to operate on the left ignition system. Ultimately, the reason for the loss of engine power could not be determined.

Quoted verbatim from the NTSB record.