COLYAER SL FREEDOM — Boynton Beach, FL

What happened

The airline transport pilot departed in his light sport aircraft with a friend, who held a student pilot certificate, on a cross-country flight to another airport for lunch. GPS data showed the airplane maneuvered near the accident site for about 30 minutes, performing multiple climbs, descents, and turns. Several witnesses reported hearing the engine "sputter," which was immediately followed by an advance in engine power. Although the airplane's final movements were not captured by witness reports or radar/GPS data, examination of the accident site showed that the airplane was in a steep descent when it impacted a swamp. The impact geometry was consistent with an in-flight loss of control and subsequent uncontrolled descent to ground impact. A postcrash fire ensued, which consumed most of the airplane.

Postaccident examination of the airplane and the engine did not reveal any mechanical anomalies that would have precluded normal operation. Although the environmental conditions were favorable for light icing at glide or cruise power, witnesses reported that the engine regained power after "sputtering"; such a gain in power is not consistent with a carburetor ice condition. The cause of the "sputtering" reported by the witnesses could not be determined because the extensive fire damage precluded testing of the engine-driven fuel pump, carburetors, and ignition system components.

The pilot reported a vibration in the control stick to the airplane manufacturer in the days leading up to the accident. The manufacturer responded to the pilot on the morning of the accident and stated that the vibration could be the result of an inadequately balanced engine or propeller. However, the propeller's effect on the airplane's performance could not be determined because two of the blades were not recovered from the accident site and the acetal pitch change slide block within the propeller hub was consumed by postcrash fire.

Although sedating medications were found in toxicological specimens from both occupants, and the pilot's autopsy found evidence of severe coronary artery disease, the investigation could not determine if these physiological conditions contributed to the accident.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.